̶1̶PREFACE
The OCU-Advanced Research Institute for Natural Science and Technology(OCARINA) sincerely invite you to its 5th International Conference as the 2012OCARINA Annual International Meeting.
The annual meeting follows the very successful previous meetings. The 1st meeting
was held at OCARINA in 2010. The third meeting was held just before the great East
Japan Earth Quake (11 March 2011; The 4th meeting was held through 7-9 March). It
past two and half years since the building and experimental facilities of OCARINA
institute has been settled. Now we will have another facility at the 2nd floor of a newly
built Comprehensive Science Research building. Even more the fully related ResearchCenter for Artificial Photosynthesis (ReCAP) for the purpose of active Collaboration
between Industry and University. Recently, it attracts very interest to utilize
alternative and renewable energy sources. This Conference invites several importantresearchers from all over the world to discuss the real future of artificial/natural
photosynthesis.
The Conference will cover the recent advances and novel progress in the field of
Natural and Artificial Photosynthesis to celebrate the settlement of the ReCAP
building. Our Institute, OCARINA and ReCAP will walk together with the Research
Organization for the 21th Century of Osaka-Prefectural University (OPU). The projectof Artificial Photosynthesis for practical achievement is so important and should be coworked with vicinal Universities. It is our great pleasure to collaborate OPU forcelebrating the future partnership.
Finally, we would like to express our sincere gratitude to Osaka City University for thefinancial support to host this important conference.

The OCU Advanced Research Institute for Natural Science and Technology(OCARINA)
Director Prof.Dr.Isamu Kinoshita

̶2̶

ÔÓ
 ¾  ã   Þ5  ÞŔŤ©Ŗ½ě©±ŢæåċDW^RJţ±ĴĨÌ§K^L`4#&9+0Ť©Ŗ½ě©±Ķ~ĝĒĚïìŢ
ðĨt2+0ĞĞ¢¢  £Śtľ?œ|".+9,  £Śtľ6  ¾4œ|*>Ťħŉ".+9+.

  ţ5¾  %ĺě+0ģ  ¾

ņ¾ŤĆį3BQ\E`Łû85ŕÈ%Š9=gŤ©Ŗ½ě©±6ć±ŇØ5Ħ5a/1!=m¼ÐĒĚK^L`Ţ 


ţ?ĺě+ŤoÇ©ŖÁě©±5  fĢ

ę±ĒĚïì2+0m¼ÐT]IAFO?Öň+0ĳ&9,åtľ

16ŤfČ£$;ÐĒĚ4ŕw,=ı3~ĆÝ?#Ò&+0Ťm¼Ð7-5ŕŇŏ4#(=âÜ5ĒĚÐê?Ďĵ+0ŝ'22:4Ť
5ĺě?ĹÊ,=)2?h3Đď2+0#<9,©Ŗ½ě©±Ķ~ĝĒĚïì_ïìő
äe


̶3̶

Date
4-6th March, 2013
Venue
10thFloor, Osaka City Univ. Media Center
Organizing committee•Prof. Dr. Hideki Hashimoto (Project Leader of OCARINA)•Prof. Dr. Isamu Kinoshita (Director of OCARINA)•Prof. Dr. Keisuke Kawakami (Special-appointment Associate Professor of
OCARINA)
Advisory Board•Prof. Dr. Richard J. Cogdell (FRS, University of Glasgow, UK)•Prof. Dr. Masakazu Anpo (Vice-President of Osaka Prefecture University,
JP)
Plenary speakers (Presentation: 50 mins, Question & Answer: 10 mins)•Prof. Dr. Leroy Cronin (University of Glasgow, UK)•Prof. Dr. Wolfgang Lubitz (Max Plank Institute for Chemical Energy
Coversion, DE)•Prof. Dr. Osamu Ishitani (Tokyo Institute of Technology, JP)•Prof. Dr. Jun Miyake (Osaka University, JP)•Prof. Dr. Bruno Robert (CEA Saclay, FR)•Prof. Dr. Ryu Abe (Kyoto University, JP)•Prof. Dr. Yutaka Amao (Oita University, JP)•Prof. Dr. Jian-Ren Shen (Okayama University, JP)•Prof. Dr. Nobuo Kamiya (Osaka City University, JP)
Invited speakers (Presentation: 25 mins, Question & Answer: 5 mins)•Prof. Dr. Tim Storr (Simon Fraser University, CA)•Dr. Rudi Berera (Vrije Universiteit Amsterdam, NL)•Prof. Dr. Masakazu Anpo (Osaka Prefecture University, JP)•Prof. Dr. Masako Kato (Hokkaido University, JP)•Prof. Dr. Masahiro Sadakane (Hiroshima University, JP)•Prof. Dr. Sachiko Matsushita (Tokyo Institute of Technology, JP)̶4̶ Prof. Dr. Shigeyuki Masaoka (Institute for Molecular Science, JP)
Prof. Dr. Yuji Furutani (Institute for Molecular Science, JP)
Prof. Dr. Hiroshi Isikita (Kyoto University, JP)
Prof. Dr. Masayuki Yagi (Niigata University, JP)
Prof. Dr. Toshio Asada (Osaka Prefecture University, JP)
Prof. Dr. Miwa Sugiura (Ehime University, JP)
Prof. Dr. Kentaro Ifuku (Kyoto University, JP)
Prof. Dr. Mitsuo Shoji (University of Tsukuba, JP)
Prof. Dr. Kenji Kano (Kyoto University, JP)
Invited speakers in OCARINA (Presentation: 25 mins, Question & Answer: 5 mins)
Prof. Dr. Ritsuko Fujii
Prof. Dr. Daisuke Kosumi
Prof. Dr. Masakazu Hirotsu
Prof. Dr. Yoshimasa Fukushima

Programme
Monday, 4th March, 201309:30~

Opening reception

10:00~10:05

Opening Remarks

10:05~10:15

Message from Michio Miyano (Vice-President of Osaka
City University)

10:15~10:45

Masakazu Anpo (Osaka Prefecture University)

10:45~11:45

Plenary lecture - Jun Miyake (Osaka University)

11:45~12:45

Poster sessions & Lunch Break

12:45~13:15

Shigeyuki Masaoka (Institute for Molecular Science)

13:15~13:45

Tim Storr (Simon Fraser University)

13:45~14:15

Sachiko Matsushita (Tokyo Institute of Technology)

14:15~14:30

Break

14:30~15:30

Plenary lecture - Bruno Robert (CEA Saclay)

15:30~16:00

Ritsuko Fujii (Osaka City University)

16:00~16:15

Break

16:15~16:45

Yuji Furutani (Institute for Molecular Science)

16:45~17:15

Miwa Sugiura (Ehime University)

17:15~18:15

Plenary lecture - Nobuo Kamiya (Osaka City University) 5 

Tuesday, 5th March, 2013
09:00~10:00

Plenary lecture - Wolfgang Lubitz (Max Plank Institute for
Chemical Energy Coversion)

10:00~10:30  Yoshimasa Fukushima (Osaka City University)
10:30~10:40  Break
10:40~11:10  Daisuke Kosumi (Osaka City University)
11:10~11:40  Mitsuo Shoji (University of Tsukuba)
11:40~13:40  Artificial photosynthesis forum, Poster sessions, & Lunch
Break
13:40~14:40  Plenary lecture - Leroy Cronin (University of Glasgow)
14:40~15:10

Masahiro Sadakane (Hiroshima University)

15:10~15:40  Rudi Berera (Vrije Universiteit Amsterdam)
15:40~15:50

Break

15:50~15:20  Kentaro Ifuku (Kyoto University)
15:20~16:50  Hiroshi Ishikita (Kyoto University)
16:50~17:50  Plenary lecture - Jian-Ren Shen (Okayama University)
18:00~   

BanquetWednesday, 6th March, 2013
09:00~10:00 Plenary lecture - Osamu Ishitani (Tokyo Institute ofTechnology)
10:00~10:30  Masayuki Yagi (Niigata University)
10:30~10:40  Break
10:40~11:10  Masakazu Hirotsu (Osaka City University)
11:10~11:40  Masako Kato (Hokkaido University)
11:40~12:40  Poster sessions & Lunch Break
12:40~13:40  Plenary lecture - Ryu Abe (Kyoto University)
13:40~14:10

Toshio Asada (Osaka Prefecture University)

14:10~14:20

Break

14:20~14:50  Kenji Kano (Kyoto University)
14:50~15:50  Plenary lecture - Yutaka Amao (Oita University)
15:50~   

Closing Remarks

̶6̶

Þá
2013 ¾ 3 ã 4 ÞŢãţ  9 á 30 ŧÇ 6 á 15 2013 ¾ 3 ã 5 ÞŢÿţ  9 áŧÇ 5 á 50 2013 ¾ 3 ã 6 ÞŢòţ  9 áŧÇ 4 áŢi´ţt¨©Ŗ½ě©±±ĴÌ§ĨK^L`10 ř©Ŗ½uæå 3 bĐ 3 č 138  Tel:06-6344-9560h|©Ŗ½ě©±Ķ~ĝĒĚïìŢOCARINAţ
Ç×©Ŗ½ě©±_ŎĀĒĚT]GZVăł°ġ5Ħĩď3©±ŘÛĭÙŜ5Öň2±mçĭÐĦĩ®
îå ĘíŢ©Ŗ½ě©±Ķ~ĝĒĚïì_T]IAFO[`M`/©±Řą±ĒĚę_ÛÕţäe Ţ©Ŗ½ě©±Ķ~ĝĒĚïì_ïìő/©±Řą±ĒĚę_ÛÕţ»d ËŢ©Ŗ½ě©±Ķ~ĝĒĚïì_Ąq

ÛÕţ

Ş¡®
Prof. Dr. Richard J. Cogdell (FRS, University of Glasgow, UK)³y ñaŢ©ŖÁě©±_ąj_±ő¤¥ŇØĒĚïìő
ÒÅĽüĬ
Prof. Dr. Leroy Cronin (University of Glasgow, UK) Prof. Dr. Wolfgang Lubitz (Max Plank Institute for Chemical Energy
Coversion, DE)
Prof. Dr. Bruno Robert (CEA Saclay, FR)
Prof. Dr. Tim Storr (Simon Fraser University, CA)
Dr. Rudi Berera (Vrije Universiteit Amsterdam, NL)đĿ ôŢèl¼ë©±©±Řą¼±ĒĚę_ÛÕţc² úŢ©Ŗ©±©±Ř¦ē¼±ĒĚę_ÛÕţŗŌ ĜŢlō©±©±Ř¼±ĒĚę_ÛÕţ̶7̶

ª· ŀŢ©©±¼±ŌÉĈ±ę_ÛÕţó ÃnŢ¹¸©±İĂę±ĒĚę_ÛÕţ³y ñaŢ©ŖÁě©±_ąj_±ő¤¥ŇØĒĚïìőţĲ ß°ŢùŊ©±©±Řą±ĒĚŘ_ÛÕţ´Ő ñöŢ¿º©±©±Ř¼±ĒĚŘ_ÛÕţée Ė°Ţèl¼ë©±©±Řą¼±ĒĚę_ÛÕţñ¹ ŎĳŢİĂę±ĒĚïì°ę±ĒĚÑ_ÛÕţĿ ĔĻŢİĂę±ĒĚïì°ę±ĒĚÑ_ÛÕţđ ­Ţlō©±Ćę±ġDW[@RJÄÐXPNO_Ą´Ûţä ÚĳŢÜý©±¼±Ō_ÛÕţšĉ xś Ţ©ŖÁě©±ą±Ō_ÛÕţæø ĪīŢÍ¯©±āĥĮĆę±¼±ĒĚK^L`_ÛÕţrė {«ŋŢlō©±©±ŘĆę±ĒĚę_ÛţÀ ĊŢğõ©±ĸĠę±ĒĚK^L`_ÛţĤ {Ţlō©±©±ŘŅ±ĒĚę_ÛÕţ±ÒÅĽüĬ
ĕĿ z¬Ţ©Ŗ½ě©±Ķ~ĝĒĚïì/©±Řą±ĒĚę_ÛÕţÂ÷ ßŢ©Ŗ½ě©±©±Řą±ĒĚę_ÛÕţĲk Æ°Ţ©Ŗ½ě©±Ķ~ĝĒĚïì_ĄqÛÕţ¶þ ©ŃŢ©Ŗ½ě©±Ķ~ĝĒĚïì_ĄqÛÕţėº v}Ţ©Ŗ½ě©±Ķ~ĝĒĚïì_ĄqÛţT]GZV
3 ã 4 ÞŢãţ09:30~    œ¨_p
10:00~10:05 œt5ń
10:05~10:15 ±őÔÓ/µŏ ŊśŢ©Ŗ½ě©±_±őţ
10:15~10:45 ³y ñaŢ©ŖÁě©±_ąj_±ő¤¥ŇØĒĚïőţ
10:45~11:45 ť¦ļĽü 1Ŧc² úŢ©Ŗ©±©±Ř¦ē¼±ĒĚę_ÛÕţ
11:45~12:45 UJL`KNHY^ & àş
12:45~13:15 ñ¹Ŏĳ ŢİĂę±ĒĚïì °ę±ĒĚÑ_ÛÕţ

13:15~13:45 Tim Storr (Simon Fraser University)
13:45~14:15 ée Ė°Ţèl¼ë©±©±Řą¼±ĒĚę_

̶8̶

ÛÕţ

14:15~14:30 sÎ
14:30~15:30 ť¦ļĽü 2ŦBruno Robert (CEA Saclay)
15:30~16:00 Ĳk Æ°Ţ©Ŗ½ě©±Ķ~ĝĒĚïì_ĄqÛÕţ

16:00~16:15 sÎ
16:15~16:45 Ŀ ĔĻŢİĂę±ĒĚïì °ę±ĒĚÑ_ÛÕţ

16:45~17:15 æø ĪīŢÍ¯©±āĥĮĆę±¼±ĒĚK^L`_ÛÕţ

17:15~18:15 ť¦ļĽü 3ŦĕĿ z¬Ţ©Ŗ½ě©±Ķ~ĝĒĚïì/©±
Řą±ĒĚę_ÛÕţ2013 ¾ 3 ã 5 ÞŢÿţ09:00~10:00  ť ¦ ļ Ľ ü 4 Ŧ Wolfgang Lubitz (Max Plank Institute for
Chemical Energy Coversion)
10:00~10:30 ėº v}Ţ©Ŗ½ě©±Ķ~ĝĒĚïì_ĄqÛţ
10:30~10:40 sÎ
10:40~11:10 ¶þ ©ŃŢ©Ŗ½ě©±Ķ~ĝĒĚïì_ĄqÛÕţ

11:10~11:40 À ĊŢğõ©±ĸĠę±ĒĚK^L`_Ûţ
11:40~13:40 m¼ÐSC`ZVŤUJL`KNHY^Ťàş
13:40~14:40 ť¦ļĽü 5ŦLeroy Cronin (University of Glasgow)
14:40~15:10 ´Ő ñöŢ¿º©±©±Ř¼±ĒĚŘ_ÛÕţ

15:10~15:40 Rudi Berera (Vrije Universiteit Amsterdam)
15:40~15:50 sÎ
15:50~15:20 rė {«ŋŢlō©±©±ŘĆę±ĒĚę_Ûţ
15:20~16:50 đ ­Ţlō©±Ćę±ġDW[@RJÄÐXPNO_Ą´Ûţ
16:50~17:50 ť¦ļĽü 6Ŧó ÃnŢ¹¸©±İĂę±ĒĚę_ÛÕţ
18:00~    Ïķt
2013 ¾ 3 ã 6 ÞŢòţ09:00~10:00 ť¦ļĽü 7ŦđĿ ôŢèl¼ë©±©±Řą¼±ĒĚę_ÛÕţ
10:00~10:30 ä ÚĳŢÜý©±¼±Ō_ÛÕţ
10:30~10:40 sÎ
10:40~11:10 Â÷ ßŢ©Ŗ½ě©±©±Řą±ĒĚę_ÛÕţ

11:10~11:40 Ĳ ß°ŢùŊ©±©±Řą±ĒĚŘ_ÛÕţ
11:40~12:40 UJL`KNHY^ & àş
12:40~13:40 ť¦ļĽü 8ŦŗŌ ĜŢlō©±©±Ř¼±ĒĚę_ÛÕţ̶9̶

13:40~14:10 šĉ xś Ţ©ŖÁě©±ą±Ō_ÛÕţ14:10~14:20 sÎ
14:20~14:50 Ĥ {Ţlō©±©±ŘŅ±ĒĚę_ÛÕţ
14:50~15:50 ť¦ļĽü 9Ŧª· ŀŢ©©±¼±ŌÉĈ±ę_15:50~  

Œt5ń

̶ 10 ̶

ÛÕţ

Invited Lectures̶ 11 ̶

̶ 12 ̶

Monday, 4th March̶ 13 ̶

̶ 14 ̶The Science and Technology of Artificial
Photosynthesis-based on Ti-oxide Photocatalysts
Masakazu ANPO
Vice President & Executive Director, Osaka Prefecture University
1-1 Gakuen-cho, Sakai-city, Osaka 599-8531, Japan
Osaka Prefecture University is a partner of the Artificial Photosynthesis ResearchCenter of Osaka City University and, in this presentation, the science and technology ofartificial photosynthesis incorporating our newly developed visible light-responsive
Ti-oxide photocatalysts will be introduced.
Environmentally harmonious, clean, safe and sustainable chemical technology andprocesses are required to address pollution and climate change and are, thus, the subjectof much research and discussion. Artificial photosynthesis, in which abundant and cleansolar energy can be harnessed, would be a major advance in the development ofsustainable, non-hazardous and cost-efficient technologies. The development of highly
functional Ti-oxide photocatalytic materials is especially promising and, significantly,
the photo-induced super-hydrophilic properties of TiO2 thin films for such applications
as self-cleaning and anti-fogging in mirrors and bone-titanium integration with highbio-compatibility have already been realized.
Unlike the natural photosynthesis in green plants, conventional photocatalytic
materials can make use of only 3-4% of the sunlight reaching earth, necessitating theuse of a UV light source. However, as we have reported since 2000, visible
light-responsive Ti-oxide photocatalytic materials which enable the absorption ofvisible light and can operate under sunlight irradiation have been successfully
developed. These developed Ti-oxide materials were found to work as effective
environmentally-friendly photocatalysts, leading to the efficient use of solar energy for
production of clean energies and other significant reactions.
This lecture introduces the most promising approaches in the development of highly
functional TiO2 thin film materials for applications in photocatalytic devices for thesolar splitting of H2O into H2 and O2 by separate evolution as well as the design of solid
solar cells and photo-induce fuel cells without the use of any organic dye sensitizers.
1) M. Anpo, M. Takeuchi, J. Catal., 216 505 (2003) and references therein.
2) M. Anpo, M. Matsuoka, Annu. Rev. Mater. Res., Ed., J.M. Thomas, 35, 233 (2005).
3) M. Matsuoka, M. Anpo, Green Catalysis, Ed., P.T. Anastas, Wiley-VCH, 59 (2009).
4) M. Anpo, P. V. Kamat, Environmentally Benign Photocatalysts, Springer (2010).

̶ 15 ̶

Pathway for BioHydrogen RealizationJun Miyake and Kazumi Hakamada
Graduate School of Engineering Science, Osaka University
1-3 Machikaneyama, Toyonaka, Osaka 560-8531 Japan
Diversification of energy is required to stabilize the supply other than oil, gas and nuclear
power. However, renewable natural power sources, such as sunlight and wind force, have
low energy density, and it is a fault that a time jitter occurs. The entropic problems in windand solar cell as collection and stabilization requires much energy.
Biomass is the most abundant energy source available in the world. Problem is the cost forthe collection of biomass. A conceptual classification is given below based on the size ofthe biomass accumulation. I should like to explain the scientific evaluation of the difficulty
and the possible technological directions, based on the table below.
Table 1. Scale and Possibility of BioEnergy Production
1. Abundant Biomass Available (as Ethanol Production Waste in Brazil)! Realistic application possible with a large scale (Very low entropy state)
2. Large Amount of Biomass Accumulation as Factory/Municipal Wastes! Application possible for special purpose (Low entropy state)
3. Community Scale Waste! The most difficult situation (High entropy state)
4. Very Remote Area without Any Other Energy Supply! Biomass Could be the Primal Energy Source
The most difficult technology should be in the category No.3. Entropic view gives us themechanism of the difficulty. Collection of biomass of a large amount needs energy, which
would be very high in some situation. The application study of biohydrogen for thecommunity is being studied by many researchers.
Bacteria are the system changed as energy which can exploit natural power sources.
Photosynthesis bacteria can be used for the large-scale reactor which changes light energy
into hydrogen by little investment, in order to carry out self-multiplication.
Accumulation of the hydrogen also reduces a time jitter. That is, it is thought that the energy
transduction of bacteria has a meaning as technology corresponding to a difficult subject(entropy) in engineering of an energy collection and equalization.
Equipment and an energy investment -- the large-scale equipment for appearing natural powersources and securing the amount of collections of cargo for using in society is needed, and alarge-scale accumulation of electricity is required to also cover a time jitter, and there is in it-- become large and difficult to serve as realistic technology easily.

̶ 16 ̶

It is thought that creation of an energy transduction method which is called the equalization ofenergy which carries out a time jitter to the thermodynamic entropy problem of accumulationof thin energy and which can similarly conquer an entropy problem is needed.
We should like to show a system design of a grid composed of several elements (Electric Grid,
Wind Turbine, Solar Cell and BioHydorgen). Effect of the reduction of entropic loss isgoing to be examined theoretically and experimentally.

Fig. BioHydrogen as an Equalization Element for Power Grid
Acknowledgements:
This work was supported by Strategic China-Japan Cooperative Programme on “Scienceand Technology (S&T) for Environmental Conservation and Construction of a Society withLess Environmental Burden” “Energy Recycling Technology for Waste and Exhaust Heat”(Jun Miyake, Osaka and Katsutoshi Hori, Nagoya, Japan and Xin-Hui Xing, Tsinghua,
China).
References:
1)
2)
3)

4)

T. Kihara, X.Y. Liu, C. Nakamura, K.M. Park, S.W. Han, D.J. Qian, K. Kawasaki, N.A. Zorin, S. Yasuda,
K. Hata, T. Wakayama, J. Miyake, Direct electron transfer to hydrogenase for catalytic hydrogenproduction using a single-walled carbon nanotube forest, Int. J. Hydrogen Energy 36, 7523-7529 (2011).
Asada, Y., Tokumoto, M., Aihara, Y., Oku, M., Ishimi, K., Wakayama, T., Miyake, J., Tomiyama, M.,
Kohno, H., Hydrogen production by co-cultures of Lactobacillus and a photosynthetic bacterium,
Rhodobacter sphaeroides RV, Int. J. hydrogen Energy 31, 1509-1513 (2006).
K. Hori, M. Ishikawa, M. Yamada, A. Higuchi, Y. Ishikawa, and H. Ebi; Production of peritrichatebacterionanofibers and their proteinaceous components by Acinetobacter sp. Tol 5 cell affected by growth
substrates, J. Biosci. Bioeng. 111, 31-36 (2010).
Feng Q, Wang Y, Wang T, Zheng H, Chu L, Zhang C, Chen H, Kong X, Xing XH. , Effects of packing
rates of cubic-shaped polyurethane foam carriers on the microbial community and the removal of organics
and nitrogen in moving bed biofilm reactors. Bioresour Technol. 117, 201-7 (2012).

̶ 17 ̶

Water Oxidation by Mono- and Multinuclear Metal Complexes
Shigeyuki Masaoka
Institute for Molecular Science, 5–1 Higashiyama, Myodaiji, Okazaki
444–8787, Japan, and PRESTO, Japan Science and Technology Agency (JST),
Honcho 4-1-8, Kawaguchi, Saitama 332-0012, Japan
Water splitting to H2 and O2 using sunlight is one of the most important chemical
processes to provide the solution for the energy and environmental problems encountered inour society. Water oxidation (2H2O  O2 + 4H+ + 4e-), one of two half-reactions for water
splitting, provides electrons and protons for the other half-reaction (hydrogen evolution).
The water oxidation step has long been considered as the bottleneck of the water-splitting
process, so the development of highly active and robust water oxidation catalysts is a key stepto accomplish light-driven water splitting.
We recently reported that some mononuclear ruthenium complexes serve as highly
active water oxidation catalysts [1], although it has long been believed that only dinuclear
metal complexes are active for water oxidation. We have also investigated the reaction
mechanism of water oxidation catalyzed by the mononuclear catalysts, revealing that thesecatalysts can be classified into two groups that have different rate-determining steps (RDS).
In one class, the RDS is a homolytic radical coupling between two catalyst species. For theother class, the step is a heterolytic radical coupling between the catalyst and the oxidant.
Based on these reaction mechanisms, new multinuclear metal complexes were designed anddeveloped as candidates for a new class of water oxidation catalysts. In this talk, recent
progress of our study will also be presented [2].
[1] (a) S. Masaoka, K. Sakai, Chem. Lett., 2009, 38, 182. (b) M. Yoshida, S. Masaoka, K.
Sakai, Chem. Lett., 2009, 38, 702. (c) M. Yoshida, S. Masaoka, J. Abe, K. Sakai, Chem. AsianJ., 2010, 5, 2369. (d) J. Kiyota, J. Yokoyama, M. Yoshida, S. Masaoka, K. Sakai, Chem. Lett.,
2010, 39, 1146. (e) A. Kimoto, K. Yamauchi, M. Yoshida, S. Masaoka, K. Sakai, Chem.
Commun., 2012, 48, 239. (f) M. Okamura, M. Yoshida, R. Kuga, K. Sakai, M. Kondo, S.
Masaoka, Dalton Trans., 2012, 41, 13081.
[2] (a) M. Kobayashi, S. Masaoka, K. Sakai, Angew. Chem. Int. Ed., 2012, 51, 7431. (b) K.
Kuroiwa, M. Yoshida, S. Masaoka, K. Kaneko, K. Sakai, N. Kimizuka, Angew. Chem. Int.
Ed., 2012, 51, 656. (c) K. Yamauchi, S. Masaoka, K. Sakai, J. Am. Chem. Soc., 2009, 131,
8404. (d) T. Yamaguchi, S. Masaoka, K. Sakai, Chem. Lett., 2009, 38, 434.

̶ 18 ̶

Oxidized Metal Phenoxide Complexes - Correlation of Electronic Structure
and Reactivity
Tim Storr,* Linus Chiang, Tim J. Dunn
Department of Chemistry, Simon Fraser University, Burnaby, BC, V5A-1S6,
Canada *Corresponding author: tim_storr@sfu.ca
The interplay of redox-active transition metal ions and pro-radical ligands inmetalloenzyme sites is an area of considerable research interest. Galactose oxidase (GOase), amononuclear copper enzyme with a Cu(II)-phenoxyl radical active oxidant, is the archetypicalexample. The simplicity of the single copper active site of the enzyme galactose oxidase,[1]which functions by catalyzing the oxidation of primary alcohols to aldehydes while reducing
dioxygen to hydrogen peroxide, has inspired efforts to develop small molecule mimics capableof mild and selective alcohol oxidation. Recent developments show that ligands serving aselectron reservoirs offer opportunities to expand catalysis, especially by conferring to first-row
transition   metals   a   “noble   metal-like”   reactivity.[2] To this end, we have investigated thechemistry of a series of simple oxidized mono- and bis-phenoxide metal complexes, which
demonstrate that small variations of the ligand structure affect the locus of oxidation.[3]Characterization of the oxidized complexes has afforded significant insight into the electronic
structure of these ligand radical systems.
Wearecurrently
investigatingbothmonometallic and bimetallic ligand radical complexes(Figure 1). The oxidized forms are characterized by bothexperimental(lowtemperature
UV-Vis-NIR
spectroscopy, electrochemistry, x-ray crystallography,
resonance Raman) and theoretical methods. DFT
calculations provide insight into the oxidation locus,
Figure 1
providing further information of the electronic structure.
We have shown that small changes to ligand structure influences ligand radical localization.
We are now using this information to probe the effect of radical localization on reactivity fora large number of mono- and bi-metallic systems.
!

References: [1] N. Ito, S. E. V. Phillips, C. Stevens, Z. B. Ogel, M. J. McPherson, J. N. Keen,K. D. S. Yadav and P. F. Knowles, Nature, 1991, 350, 87. [2] P. J. Chirik and K. Wieghardt,
Science, 2010, 327, 794. [3] L. Chiang, A. Kochem, O. Jarjayes, T. J. Dunn, H. Vezin, M.
Sakaguchi, T. Ogura, M. Orio, Y. Shimazaki, F. Thomas and T. Storr, Chem. Eur. J., 2012, 18,14117; T. J. Dunn, M. I. Webb, K. Hazin, P. Verma, E. C. Wasinger, Y. Shimazaki and T. Storr,
Dalton Trans., 2013, DOI:10.1039/C2DT32632A.

̶ 19 ̶Preparation of Mesoporous Oxide Monoliths and the
Photocatalytic Activity    
Sachiko Matsushita*, Takashi Nogawa, Toshihiro Isobe, Akira Nakajima
Department of Metallurgy & Ceramics Science, Tokyo Institute of Technology,
2-12-1, Ookayama, Meguro-ku, Tokyo 152-8552, JAPAN okyo Institute of Technology,JAPANe-mail: matsushita.s.ab@m.titech.ac.jp
An organic monolith is a continuousinterconnected skeleton with large through-pores.
This structure reduces the diffusion path andprovides high permeability, resulting in excellent
separation efficiency. Such organic monolith, which
can be produced by self-organization in polymer
phase separation, might be an excellent template asa catalyst.[1] In this research, porous spherical metaloxide particles were prepared by impregnation of a
Titanium precursor and Si precursor solution into

Ti20%-500
Ti20%-600
Ti40%-500
1

the organic monolith sphere particles (8 µm
diameter, MBP-8, Sekisui Plastics Co. Ltd.) at room
Figure 1. Ti precursor concentration andcalcining temperature dependence of poretemperature, with subsequent calcining in air. The
size distribution for obtained TiO2 –SiO2
scanning electron microsopy (SEM), and N2
composite particles. The SEM image of thesamples sintered at 500 is shown in inset.
adsorption-desorption isotherms and BJH
equation analysis revealed that our samples
were porous spheres mainly sized pores ofaround 2 and 10 nm (Fig. 1). Larger poresof around 55 nm were also convinced by
SEM observations.
Addition of Si precursor decreased theTiO2 crystallinity and increased the specificsurface area and the width of bandgap (Fig.
2). The photocatalytic reduction activities of
Ti40%
Ti20%
Ti20%
these samples were examined using
-500
-600
-500
Figure 2. Total pore area and bandgap for obtained
CO2–vapor under UV light irradiation. The
TiO2 –SiO2 composite particles. The volume
persentage of titanium precursor in raw materials andgeneration of CO was convinced.
the sintered tempaerature were noted at bottom.

References: [1] Uchiyama, S.; Isobe, T.; Matsushita, S.; Nakajima, K.; Hara, M.; Nakajima,A., J. Mater. Sci. 2011, 47 (1), 341.
̶ 20 ̶

Molecular Basis of Photoprotection
Bruno RobertInstitute of Biology and Technology CEA Saclay, 91191 Gif/Yvette Cedex. France
bruno.robert@cea.fr

Through their light-harvesting antenna, plants frequently absorb more solar energy than they
can use in photosynthesis. This excess energy has the potential to cause cell damage, such as
pigment bleaching and protein inactivation. To minimise photodamage, a number ofprotection mechanisms exist, which we have characterized at a molecular/functional level. I
will discuss the following mechanisms in the light of our most recent results
Protection against photooxidative stress induces by high light environments : shaping
proteins in large multimolecular architectures
Excitation energy quenchers rapidly appear in the photosynthetic membrane of plants andalgae when these organisms are exposed to high illumination conditions. Until recently, thismechanism was still poorly understood. In the last years, combined use of advanced
spectroscopic methods, first applied on isolated light-harvesting complexes then developed
for their application on systems as complicated as whole leaves, have yielded a precise pictureof the molecular events which underlie this important mechanism of photoprotection in higher
plants. I will report recent results showing that these mechanisms actually occur upon thebuild-up of the large macrocomplexes of photosystem II,i.e.that the protein-protein
interactions in these complexes shape the structure and function of antenna proteins.
Triplet-triplet transfers between chlorophyll and carotenoid molecules : from natural to
artificial photosynthesis
We recently showed that in most light-harvesting proteins of oxygenic organisms, the pigment
organization dramatically modify the properties of the triplet states, in order to minimize theproduction of singlet oxygen. I will report the excitation energy cascade in these complexes,
as well as in artificial systems such as phtalocyanin/carotenoid dyads, and how we can accessto the structure of these triplet states.

̶ 21 ̶

Structure of siphonaxanthin bound to
the newly isolated photosynthetic antennafrom a deep-sea green alga, Codium intricatum    
FUJII, Ritsuko1,2; SHIGEMATSU, Yusuke3; OKA, Naohiro4; IHA, Masahiko4;
HASHIMOTO, Hideki1,3,5
1
OCARINA/OCU; 2JST-PRESTO; 3Osaka City Univ.; 4South Product Inc.; 5JST-CREST
Abstract: One of an issue of the Solar-fuel system is how to utilize the low-density photon
from the sun. Natural photosynthetic organisms have developed a variety of light-harvesting
system, so-called "photosynthetic antenna", to collect the photon to transfer the excitedenergy to the reaction center in a proper time scale. At 10-20 m below the sea level, only a
dim blue-green light can penetrate. Thus the photosynthetic antenna of deep-sea phototrophs
shows highly efficient light-harvesting function. We aimed to extract the essence of theefficient energy utilization system to make use of the result for the Solar-fuel system.
Some of green alga from deep sea shows olive drab color and they are called "siphonous"
green alga because they have a unique pigment, siphonaxanthin (Sx). It is bound to thephotosynthetic antenna, Sx-chlorophyll a/b protein (SCP), and harvest blue-green region oflight. The Sx content were quite scattering among the collected alga from the seashore. We
have been recently successful to optimize the Sx content by culturing one of the siphonous
green alga, Codium intricatumOkamura as its filamentous body. In this study, we purified the
SCP and determined its partial primary structure by MALDI-TOF-MS/PSD, and its
quaternary structure by Blue Native-PAGE, as well as its pigment compositions by a
combination of HPLC, LC-MS, and 1H-NMR. The SCP forms a trimer consists of a subunit,
whose partial sequences show high homology to thewell-studied light-harvesting complex from higher
plants, LHCII. Pigment analyses revealed that both
Sx and Sx C12:O ester (see the figure)were equallybound to the SCP and the pigment composition was
identical to that of the LHCII except for Sx and Sx
ester is the substitutes for the two molecules of lutein.
Therefore the structure of Sx (and Sx ester) in the
SCP can be estimated by using the X-ray structure of
the pea LHCII at 2.5Å resolution [1].
References: [1] Standfuss, J.; van Scheltinga, A.C.
T.; Lamborghini, M; Kühlbrandt, W. Embo J. 2005,
24, 919.

̶ 22 ̶

Fig. Chemical structures of carotenoids andabsorption
spectraofcorresponding
photosynthetic antennae

Water Molecules and Ions in Membrane Proteins
Studied by FTIR Spectroscopy
Yuji Furutani1,2,3
1

Department of Life and Coordination-Complex Molecular Science,

Institute for Molecular Science, 38 Nishigo-Naka, Myodaiji, Okazaki 444-8585, Japan2
Department of Structural Molecular Science, The Graduate University for Advanced
Studies (SOKENDAI), Myodaiji, Okazaki 444-8585, Japan
3
PRESTO, Japan Science and Technology Agency(JST),
4-1-8 Honcho Kawaguchi, Saitama, 332-0012, Japan

Abstract: Membrane proteins play crucial roles for receiving external stimuli, transportingand permeating protons and ions to genere biological energy and signal, and incorporating
nutrients and excreting unfavorable chemicals, and so on. The molecular mechanisms ofmembrane proteins have been deepened with the progress in structural biology. Elucidationof atomic structures of various kinds of G protein coupled receptors (GPCRs) and its active
form complex with G protein is a milestone, leading to the Nobel prize in chemistry 2012.
Another great progress was done by Japanese groups (Profs. Kamiya and Shen). They
revealed the precise coordination structure of the Mn cluster in photosystem II, which
impacted on chemists in various fields, especially the researchers aiming to realize artificial
photosynthesis. However, X-ray crystallography captures a static structure of protein
restricted by steric constraint in the crystal lattice. The structural changes which connect theinactive and active states of protein should be elucidated by using other physicochemical
methods.
Fourier-transform infrared (FTIR) spectroscopy is one of powerful method forinvestigating molecular structures in the level of chemical bonds. In general, large numberof atoms in a protein molecule hampers resolving each normal mode in the infrared spectrum.
Therefore, stimulus-induced difference infrared spectroscopy has been applied to extract
structural changes of protein in response to various stimuli. Light is one of important
stimulus for life and can be easily controlled by modern electronics and laser techniques.
Inorganic ions permeate ion channels and are vectoriay transported by pumps and transporters.
The selectivity of ions, especially discrimination between potassium and sodium ions, isimportant for understanding the molecular mechanisms of the ion channels and transporters.
In this talk, I’d like to introduce my recent studies on a light-driven chloride ion pump,pharaonis halorhodopsin (pHR), and a potassium ion channel, KcsA. The structural changesof pHR including water molecules inside protein has been revealed by time-resolved FTIR
spectroscopy. We analyzed the dynamics of the dangling bonds of water molecules, which̶ 23 ̶

are free from the hydrogen-bonding network, and discussed the relationship with theion-transporting mechanism [1]. KcsA is a well-known potassium ion channel whose
precise X-ray structures in various conditions have been reported. We have applied
attenuated total reflection FTIR (ATR-FTIR) spectroscopy to reveal the ion-protein
interaction of the selectivity filter of KcsA, which is a special part for discriminating
potassium ions from sodium ions. We succeeded to assign the C=O stretching vibrations of
the selectivity filter in the amide I region [2]. By analyzing the bands, we characterized thecoordination structure of the carbonyl groups and the affinity for potassium ions.
FTIR spectroscopy could be a complementary method for investigating the structuralchanges of protein as a result of reception of various stimuli and specific interactions withions, ligands, and inhibitors. After revealing X-ray crystal structures of proteins, FTIR
spectroscopy would help the researchers to investigate the molecular mechanisms of theproteins in more detail.
References:[1] Furutani, Y.; Fujiwara, K.; Kimura, T; Kikukawa, T.; Demura, M.; Kandori, H. J. Phys.
Chem. Lett. 2012, 3, 2964.
[2] Furutani, Y.; Shimizu, H.; Asai, Y.; Fukuda, T.; Oiki, S.; Kandori, H. J. Phys. Chem. Lett.
2012, 3, 3806.

̶ 24 ̶

Regulation of electron transfer in Photosystem II
Miwa SUGIURA
Cell-Free Science and Technology Research Center, Ehime University
JST-PRESTO
In the photosynthetic primary process of plants, algae and cyanobacteria, Photosystem II(PSII) cooperates in series to convert photon energy into chemical energy throughlight-induced charge separation and subsequent electron transfers.

The light-driven wateroxidation by PSII enzyme is responsible for the production of O2 on Earth, and is at the originof the synthesis of most of the biomass.
supracomplex

thatconsists

PSII is a

with

17

membrane-spanning proteins and 3 extrinsic proteins
involving over 80 cofactors such as chlorophylls,
ß-carotenes, non-heme irons, plastoquinones, lipids,
and so on [1].

The reaction centre proteins, D1 andFig. 1. Electron transport and water oxidation in PSII.

D2, bind all the redox-active cofactors involved in the energy conversion process and thefollowing sequence of reactions occurs.

As shown in Fig. 1, firstly, a special form of Chla,

P680, acts as an exciton trap and converted to a strong reducing agent after excitation (P680*).
Within a few picoseconds, P680* reduces a pheophytin (Pheo) to form the radical par state
P680+•Pheo-•, then Pheo-• reduces a primary plastoquineone QA to produce P680+•Pheo-•.

The

P680+•, which has a very high redox potential (> 1.2 V), oxidises a TyrZ to form
TyrZ+•P680PheoQA- on a nanosecond.

On a millisecond scale, QA- reduces a second

plastoqunone QB to form TyrZ+•P680PheoQAQB-.
proton from a Mn4CaO5 cluster.

The oxidised TyrZ+• extracts an electron andA second photochemical turnover reduces QB- to QB2-.

Two further photochemical turnovers provide the Mn4CaO5 cluster with a total of fouroxidising equivalents.

̶ 25 ̶

The main cofactors involved in the function of PSII are borne by the D1 and D2
proteins.

In cyanobacteria, the D1 protein may be encoded by several psbA genes which are

known to be possibly expressed differentially depending on the environmental conditions.
In the cyanobacterium Thermosynechococcus elongatus there are 3 different psbA genes
coding for D1. Among the 344 residues constituting D1 there are 21 differences between
PsbA1 and PsbA3, 31 between PsbA1 and PsbA2 and 27 between PsbA2 and PsbA3.

By

those substitutions functions of PSII are modified especially in water oxidation rate and redox
potentials of cofactors[1-6].

In this symposium, regulation system of D1 gene expression

and functional difference due to the partial modification of structure in PSII complexes.
References:[1] Umena, Y.; Kawakami, K.; Shen, J.-R.; Kamiya, N. Nature 2011, 473, 55.
[2] Sugiura, M.; Kato, Y.; Takahashi, R.; Suzuki, H.; Watanabe, T.; Noguchi, T.; Rappaport,
F.; Boussac, A. Biochim. Biophys. Acta 2010, 1797, 1491.
[3] Ogami, S.; Boussac, A.; Sugiura, M. Biochim. Biophys. Acta 2012, 1817. 1322.
[4] Sugiura, M.; Ogami, S.; Kusumi, M.; Un, S.; Rappaport, F.; Boussac, A. J. Biol. Chem.
2012, 287, 13336.
[5] Kato, Y.; Sugiura, M.; Oda, A.; Watanabe, T. Proc. Natl. Acad. Sci. U.S.A. 2009, 106,17365.
[6] Kato, Y.; Shibamoto, T.; Yamamoto, S.; Watanabe, T.; Ishida, N.; Sugiura, M.;
Rappaport, F.; Boussac, A. Biochim. Biophys. Acta 2012, 1817, 1998

̶ 26 ̶

Structure and Function of Mn4CaO5 Cluster
Water-Splitting and Oxygen-Evolving Photosystem IIinNobuo Kamiya, The OCU Advanced Research Institute for Natural
Science and Technology (OCARINA), Osaka City University, Osaka
558-8585, Japan. E-mail: nkamiya@sci.osaka-cu.ac.jp
Photosystem II (PSII) performs light-induced electron transfer and water-splitting
reactions leading to the formation of molecular oxygen. PSII from thermophilic cyanobacteria
consists of seventeen membrane-spanning subunits, three hydrophilic, peripheral subunits,
and many cofactors with a total molecular weight of 350 kDa for a monomer. Recently,
crystal quality of PSII from Thermosynechococcus vulcanus has been improved significantly,
and the crystal structure has reported by our group at a resolution of 1.9 Å [1]. Electron
density distributions for each of the five metal ions in the water-splitting and oxygen-evolving
Mn4Ca-cluster are clearly separated to locate the individual metal ions and all of the ligands
to the metal cluster unambiguously. Five oxygen atoms forming oxo-bridges between themetal ions are identified, and four water molecules are found to be associated with the metalcluster, some of which may serve as substrates in the oxygen-evolving reaction. The mostsignificant structural feature of the Mn4CaO5 cluster is its distorted chair form. The large
distortion from a symmetric cubane is principally caused by the existence of Ca and O5, thefifth oxo-bridge connecting three Mn and one Ca ions. The distances between the three Mnions and O5 are remarkably longer than those between the other oxygen and Mn ions. Thissuggests that the bonds between O5 and each of the Mn ions are weak, implying that O5 isapparently different from the other four oxygen atoms. It may also suggest that O5 may exist
as a hydroxide ion in the S1-state of the Kok cycle, as supported recently by DFT calculations[2]. In order to elucidate the mechanism of PSII oxygen evolution, it is crucial to identify thetwo substrate-water molecules participating in the O-O bond formation. Based on the above
structural features revealed, O5 may form part of the reaction site. Among the four watermolecules bound to the Mn4CaO5 cluster, two are located most closely to O5, with theirdistances to O5 around 3 Å. In addition, these two water molecules have a distance of 3.3 Å
between each other. Thus, there is a possibility that O-O bond formation is taken place withinthese two water molecules and O5.
Based on the detailed structure of the Mn4CaO5 cluster, many researchers may be atpresent making their efforts towards developing novel water-splitting and oxygen-evolving
catalysts. The most difficult problem may be how to realize the asymmetry like the Mn4CaO5cluster in their catalysts.
[1] Y. Umena, K. Kawakami , J.-R. Shen, N. Kamiya, Nature 473 (2011) 55-60.
[2] H. Isobe, M. Shoji, S. Yamanaka, Y. Umena, K. Kawakami, N. Kamiya, J.–R. Shen, K.
Yamaguchi, Dalton Trans., 41, (2012) 13727-13740.

̶ 27 ̶

̶ 28 ̶

Tuesday, 5th March̶ 29 ̶

̶ 30 ̶Light-Induced Water Splitting and Hydrogen
Production: Learning from Nature
Wolfgang Lubitz
Max Planck Institute for Chemical Energy Conversion (CEC),Stiftstrasse 34-36,
45470 Mülheim an der Ruhr, Germany
Storage of the sun’s energy in “solar fuels” like molecular hydrogen or related molecules
using water as basic material is a research topic of great important for our society.
A promising starting point for the development of synthetic sun light-driven water splitting
catalyst, is to use Nature’s approach for inspiration, which is realized in oxygenic
photosynthesis.[1] In this process, found in green plants, algae and cyanobacteria, wateroxidation occurs in a unique biological supercomplex (Photosystem II, PSII). This harbours
an oxygen-bridged tetra-nuclear manganese/calcium cluster as catalytic site embedded in asmart protein matrix.[2] Many green algae and bacteria also contain enzymes that enablehydrogen evolution from excess protons, the hydrogenases.[3,4]The implementation of “artificial photosynthesis” represents a major challenge as chemists
are at present not yet able to design and synthesize devices that are able to mimic the naturalprocesses in an efficient way, i.e. with low overpotential, high turnover rates and sufficientstability (long lifetimes) of the catalysts. One major difficulty is the poorly understoodcoupling of the light-induced one-photon/one-electron charge separation to the multi-electron
catalytic processes leading to water oxidation and fuel production. In addition, Nature uses
the protein surrounding to optimize the enzymatic process; the matrix is also protection andallows efficient repair in vivo. In this respect chemically synthesized systems are currently by
far inferior to the native ones.
In recent years high resolution X-ray crystallographic structures of PSII [2] and differenthydrogenases [3-6] have been obtained and additional spectroscopic and electrochemical
experiments have very significantly increased our knowledge about the structure and functionof the native enzymes. Slowly, a mechanistic understanding of the underlying processes isdeveloping.[3,7] This knowledge will help to advance the field of artificial photosynthesis,
aiming at synthesizing new catalysts for large scale water splitting, hydrogen production orenergy storage in other chemical compounds, processes that are of key importance for asustainable energy future.
In this lecture the native enzymes wateroxidase and hydrogenase are presented and theirworking mechanisms are discussed.[1] Prospects of native biological and chemical systems tosolve the energy problem will also be addressed.

̶ 31 ̶

References:[1] Cox, N.; Lubitz, W. Molecular Concepts of Water Splitting: Nature’s Approach. In:
Chemical Energy Storage, R. Schlögl (ed.), De Gruyter, Berlin/Boston 2013, pp.185 224.
[2] Umena, Y.; Kawakami, K.; Shen, J.-R.; Kamiya, N. Nature 2011, 473, 55.
[3] Lubitz, W.; Ogata, H.; Reijerse, E.; Higuchi, Y. Structure and Function of Hydrogenase
Enzymes. In: Molecular Solar Fuels, T.W. Wydrzynski, W. Hillier (eds.), RSC
Publishing; Cambridge 2012, pp. 288 - 325.
[4] Fontecilla-Camps, J.C.; Amara, P. ; Cavazza, C.; Nicolet, Y.; Volbeda, A. Nature 2009,
460, 814.
[5] Fritsch, F.; Scheerer, P.; Frielingsdorf, S.; Kroschinsky, S.; Friedrich, B.; Lenz, O.; Spahn,
C.M.T. Nature 2011, 479, 249.
[6] Shomura, Y.; Yoon, K.-S.; Nishihara, H.; Higuchi, Y. Nature 2011, 479, 253.
[7] Cox, N.; Pantazis, D.; Neese, F.; Lubitz. W. Acc. Chem. Res. 2013, in press

̶ 32 ̶

 Photoreaction analysis of flavin photoreceptor BLUF domain
by cryogenic spectroscopy    
Yoshimasa Fukushima
The OCU Advanced Research Institute for Natural Science and Technology
Osaka city university, 3-3-138, Sugimoto, Sumiyoshi, Osaka, 558-8585 Japan
BLUF (sensor of Blue Light Using Flavin) domain is a class of flavin-binding photoreceptor
that is distributed among genomes of bacteria and some eucaryotes. Cyanobacterial
BLUF-domain protein PixD is related to the cell motility. Three types of flavin protein
families, BLUF, LOV (Light, Oxygen and Voltage sensing) and PHR (Photolyase Homology
Region) domains are known to function as a photoreceptor. They show somewhat different
photoreactions. The photoreaction of the BLUF-containing protein TePixD of acyanobacterium Thermosynechococcus elongatus BP-1 have been studied by cryogenic
spectroscopy, nano second time-resolved spectroscopy, and site-directed mutagenesis on theconserved residues around the flavin chromophore.
Absorption spectrum of flavin in TePixD shows the ~10 nm red shift upon the illumination
at 283 K [1]. H-bondings between flavin and the surrounding amino acid seem to be modified
coupled to the red-shift as also shown for other BLUF domain proteins by FTIR or Raman
spectroscopy. The red-shifted form was found to appear at 10 ns after the laser flash
excitation suggesting the fast photoconversion to the red-shifted form from the singlet-excitedstate of flavin at room temperature. This type of photoreaction is different from the otherflavin-binding proteins LOV and PHR domains that form triplet state or electron transferredstate of flavin. Illumination of wild-type protein at 10 K, on the other hand, induced only the 5
nm red shift of flavin. The 5 nm-shifted form was stable at 10 K, and was converted to the~10 nm-shifted form on warming to 50-240 K in the dark. The 5 nm-shifted form, thus, seems
to be an intermediate state with a small conformational changes around flavin. The mutant
proteins, in which either Tyr8 or Gln50 is replaced, did not show the proper photoconversion
at room temperature [2]. Gln50 is directly H-bonded to flavin but Tyr8 indirectly interacts
with flavin via H-bond with Gln50. Y8F and Y8A mutant proteins formed higher extents of
triplet state of flavin as found in the LOV domain proteins. We concluded that conformationalor redox change of flavin itself is very limited in the red-shifted intermediates. We will
discuss how the protein environment determines the photoreaction of flavin.
References:[1] Fukushima, Y.; Okajima, K.; Shibata, Y.; Ikeuchi, M.; Itoh, S. Biochemistry 2005, 44,5149.
[2] Okajima, K.; Fukushima, Y.; Suzuki, H.; Kita, A.; Ochiai, Y.; Katayama, M.; Shibata, Y.;
Miki, K.; Noguchi, T.; Itoh, S.; Ikeuchi, M. J. Mol. Biol. 2006, 363, 10.
̶ 33 ̶

Ultrafast Excited State Dynamics of Fucoxanthin: A Role ofIntramolecular Charge Transfer in Brown Algal
Light-harvesting
Daisuke Kosumi1,2, Ritsuko Fujii1,3, Mitsuru Sugisaki2,4, Masahiko Iha5,
Shigeo Katsumura6, and Hideki Hashimoto1,2,4
1

The Osaka City University Advanced Research Institute for Natural Science and Technology(OCARINA), 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585, Japan
2
JST/CREST, 4-1-8 Hon-chou, Kawaguchi, Saitama 332-0012, Japan
3
JST/PRESTO, 4-1-8 Hon-chou, Kawaguchi, Saitama 332-0012, Japan
4
Department of Physics, Graduate School of Science, Osaka City University
5
South Product Co. Ltd., 12-75 Suzaki, Uruma-shi, Okinawa 904-2234, Japan
6
Department of Chemistry, Kwansei Gakuin University, Hyogo 669-1337, Japan

Fucoxanthin-chlorophyll a/c protein (FCP) complexes from brown algae, Cladosiphon
okamuranus TOKIDA (Okinawa Mozuku in Japanese), contain the carbonyl-carotenoid,
fucoxanthin [1], which exhibits spectral characteristics attributed to an intramolecular chargetransfer (ICT) state located nearby the lowest S1 excited state in polar environments due to thepresence of the carbonyl group in its polyene backbone as shown in Fig. (A) [2]. In the FCP
complexes, fucoxanthin molecules absorb light energy in the blue-green region of thespectrum (Fig. (B)) and transfer it to nearby chlorophylls rapidly and efficiently [1,3].
Recent ultrafast spectroscopic techniques have revealed the ultrafast dynamics of the ICT
state of carbonyl-carotenoids and its role in excitation energy transfer of aquatic algal
photosynthetic antennas [3]. However, details of the nature and function of the ICT state
have been still matters of debate. In this study, we investigated (1) the role of the ICT
property of fucoxanthin in ultrafast energy transfer tochlorophyll a/c in brown algal photosynthetic
antennas and (2) the molecular nature of the ICT stateof fucoxanthin molecules with various conjugation
lengths [4] in solvent environments using
femtosecond
pump-probe
spectroscopic
measurements.
[1] R. Fujii et al., Photosynth. Res., 111, 165, 2012.
[2] D. Kosumi et al., Phys. Chem. Chem. Phys., 13, 10762,
2011.
[3] T. Polívka and V. Sundström, Chem. Rev., 104, 2021,
2004.
[4] T. Kajikawa et al., Org. Lett., 14, 808-811, 2012.

̶ 34 ̶

Figure: (A) A chemical structure offucoxanthin and (B) the steady-state
absorption spectrum of the isolated FCP
complex.

A QM/MM study on the S2 spin state of the oxygen-evolving complex    
Mitsuo Shoji,1 Hiroshi Isobe,2 Shusuke Yamanaka, 2
Jian-Ren Shen, 3 Kizashi Yamaguchi2
1
Graduate School of Pure and Applied Science, University of Tsukuba
2Graduate School of Science, Osaka University
3
Graduate School of Natural Science and Technology, Okayama University
Oxygen-evolving complex (OEC) is a key reaction center in photosystem II (PSII) for theoxidation reaction of water to dioxygen. The OEC cycles through five redox states (Si, i =0-4) with the extraction of four electrons and four protons. Umena and co-workers havedetermined the high-resolution x-ray structure at the 1.9A, and revealed the fine 3D structureof OEC, including the CaMn4O5 cluster and close waters [1]. The OEC forms manyhydrogen-bonds with neighboring waters and residues, it is not obvious for the electronic andspin structure at the ground state.
In this study, the ground spin state of OEC at the S2 state was examined by using a QM/MM
approach. Ground spin state is one of the important characters to check the validity ofcomputational results. The high-resolution x-ray structure was used as a starting model (Fig.
1). A large QM region was used including second coordination amino acids and waters.
Geometry optimizations were performed for the QM/MM model. We fond that calculated
ground spin state is (4/2, -3/2, 3/2, -3/2) at the (III, IV, IV, IV) charge state for Mn centers,
respectively. This result is consistent to the recent EPR result. The magnetic interactions
between Mn centers were evaluated to evaluate the Heisenberg exchange parameters
following the generalized spin projection scheme [2].

Figure 1. QM atoms used in the QM/MM calculations.
References:[1] Umena, Y.; Kawakami, K.; Shen, J-R; Kamiya, N. nature 2011, 473, 55.
[2] Shoji, M. et al. Chem. Phys. Lett. 2006, 432,343.

̶ 35 ̶

New Paradigms in Water Splitting
Lee Cronin, School of Chemistry, University of Glasgow,
Glasgow, G12 8QQ, UK
Email: Lee.Cronin@glasgow.ac.uk
Web: www.chem.gla.ac.uk/staff/lee!
!
The!need!for!sustainable,!carbon3neutral!technologies!to!meet!the!world’s!growing!demand!for!
energy! has! become! a! widely! acknowledged! imperative.! However,! despite! this! realization,!
renewable!energy!sources!such!as!wind!and!solar!power!remain!under3exploited!as!large3scale!
replacements!for!fossil!fuels.[1]!This!is!largely!due!to!the!intermittency!of!supply:!a!reliable!way!
of!storing!the!energy!generated!by!renewable!sources!must!be!found!in!order!to!compensate!
for! periods! during! which! the! wind! does! not! blow! or! the! sun! does! not! shine.! An! especially!
attractive! solution! to! this! problem! is! to! store! sustainably3generated! energy! in! the! form! of!
chemical!bonds!by!the!electrochemical!or!photochemical!splitting!of!water!to!produce!oxygen!
and!hydrogen.!Here!we!describe!the!development!of!‘proton3
electron3buffers’! (PEBs)! using! redox3active! polyoxometalate!
(POM)! clusters! that! are! be! able! to! address! the! problem! of!
simultaneous! oxygen! and! hydrogen! production! during! the!
electrolysis!of!water,!Figure!1.!!
Figure! 1! shows! the! CV# of# 0.5# M# H3Mo12PO40# (black# line)# and# 1# M# H3PO4#(dashed#line,#to#show#where#OER#and#HER#onset#occur).#A#threeFelectrode,#
single#compartment#setup#was#used,#with#a#2#mm#diameter#Pt#disc#working#electrode,#Pt#wire#counter#electrode#and#an#Ag/AgCl#reference#electrode#at#
F1
a# scan# rate# of# 100# mVs .# The# green# arrows# highlight# the# oxidation# and#reduction#peaks#associated#with#the#first#reduced#state#of#H3Mo12PO40.!

!
Using! a! PEB! in! an! electrolyser! could! also! bring! significant! advantages! with! regards! to!
intermittent! power! supplies! (such! as! renewables)! by! reducing! the! instantaneous! voltages!
required!for!electrolysis!to!occur.!In!addition!to!exploring!water!splitting!through!the!paradigm!
of!the!proton3electron3buffer,!we!will!also!describe!the!use!of!reduced!polyoxometalate!clusters!
as! an! intermediate! “fuel! source”,! by! reacting! the! reduced! PEBs! with! reducible! chemical!
substrates!(possibly!including!low!grade!organic!waste!products)!to!produce!storable!fuels.!
!
1.!R.!J.!Cogdell,!T.!H.!Brotosudarmo,!A.!T.!Gardiner,!P.!M.!Sanchez,!L.!Cronin,!Biofuels,!2010,!1,!8613876.
2.!D.!–L.!Long,!R.!Tsunashima,!L.!Cronin,!Angew.#Chem.#Int.#Ed.,!2010,!49,!173631758.!

Catalytic activity of-oxo dimmer of mono-ruthenium-Keggin-type heteropolytungstates for water
substitutedoxidation.
Masahiro Sadakanea)b), Hiroaki Kitatomia), Shuhei Ogoa), Tsuneji Sanoa)a) Applied Chemistry, Graducate School of Engineering, Hiroshima Universityb) PRESTO JST
Abstract: We present -oxo dimeric species of the mono-ruthenium substituted
heteropolytungstates, [{XW11O39Ru}2O)]n- (X = Si or Ge) (Fig 1 (right)), show WOC activity
using CAN as an oxidant without decomposition to the monomeric species.
Development of efficient and robust water oxidation catalyst (WOCs) is one of the mostimportant keys for realization of artificial photosynthesis which could be a solution for theenergy problem worldwide. Heteropolytungstates are discrete tungsten-oxide molecules withother elements that have recently been attracting increasing interest because of their WOC
activities [1]. Bonchio and Hill groups reported another sandwich-type heteropolytungstatewith tetranuclear ruthenium core, [( -SiW10O36)2Ru4O4(OH)2(H2O)4]10-, showed high catalytic
activity for water oxidation using cerium ammonium nitrate (CAN) or [RuIII(bpy)3]3+ as anoxidant. Hill group reported high catalytic activity of a sandwich-type heteropolytungstatewith tetranuclear cobalt core, [(PW9O34)2Co4(H2O)]10-, using [RuIII(bpy)3]3+ as an oxidant.
Fukuzumi group reported that mononuclear ruthenium substituted heteropolytungstates,[XW11O39RuIII(H2O)]5- (X = Si or Ge) (Fig 1 (left)), show WOC activity using CAN as anoxidant. They proposed that oxo-Ru species is active species [2].
We reported that the mono-ruthenium substituted heteropolytungstates (Fig 1 (left)dimerized to form -oxo dimeric species, [{XW11O39Ru}2O)]n- (X = Si or Ge) (Fig 1 (right))[3]. We present WOC activity of these dimeric species.

Fig 1. Structure of (left) [XW11O39Ru(H2O)]n- and (right) [{XW11O39Ru}2O)]n- (X : Si or Ge).
The dimer showed catalytic acitivity for water oxidation using CAN as an oxidant (Fig 2).
Ru in the dimeric species was coordinated by five oxygen of polyoxotungstate and one -oxobridged two mono-ruthenium substituted polyoxotungstates. There is no example where such
-oxo dimer is active as WOC. Therefore, it could be consider that monomeric species
generated by dissociative decomposition of the dimer acted as an active species. However, we̶ 37 ̶

Template for the abstract
indicated that the dimer worked as a real catalyst.
㪈㪍㪇㪜㫍㫆㫃㫌㫋㪼㪻㩷㫆㫏㫐㪾㪼㫅㩷㪆㩷P㫄㫆㫃

㪈㪋㪇
㪈㪉㪇
㪈㪇㪇
㪏㪇
㪍㪇
㪋㪇
㪉㪇
㪇
㪇

㪌㪇

㪈㪇㪇

㪈㪌㪇

㪉㪇㪇

㪉㪌㪇

㪫㫀㫄㪼㩷㪆㩷㫄㫀㫅㫌㫋㪼㫊Fig 2. Time course of oxygen evolution catalyzed by (green) Si-monomer, (blue) Si-dimer,(black) Ge-monomer, and (pink) Ge-monomer. Ru concentration: 60 PM, CAN
concentration: 6 mM in 100 mL of 0.1 M HNO3.
Fig 2 shows time course of oxygen evolution catalyzed by monomers and dimers in same
Ru concentration. Oxygen evolution rate using Si-monomer catalyt is faster than Si-dimer
catalyst but reaction rate became slower in the course of reaction. Amount of oxygen
produced using Si-dimer catalyst became larger than amount of oxygen using Si-monomer
catalyst in the cource of reaction. Furthermore, catalytic activity of Ge-dimer is higher than
Ge-monomer. These results indicated that dimer is a real catalyst.
㪋㪇㪇㪜㫍㫆㫃㫌㫋㪼㪻㩷㫆㫏㫐㪾㪼㫅㩷㪲P㫄㫆㫃㪴㪜㫍㫆㫃㫌㫋㪼㪻㩷㫆㫏㫐㪾㪼㫅㩷㪲P㫄㫆㫃㪴

㪋㪇㪇

㪊㪇㪇

㪉㪇㪇

㪈㪇㪇

㪇

㪊㪇㪇

㪉㪇㪇

㪈㪇㪇

㪇
㪇

㪌㪇

㪈㪇㪇

㪈㪌㪇

㪉㪇㪇

㪇

㪫㫀㫄㪼㩷㪲㫄㫀㫅㫌㫋㪼㫊㪴

㪉㪇

㪋㪇

㪍㪇

㪏㪇

㪈㪇㪇

㪈㪉㪇

㪈㪋㪇

㪈㪍㪇

㪈㪏㪇

㪉㪇㪇

㪫㫀㫄㪼㩷㪲㫄㫀㫅㫌㫋㪼㫊㪴Fig 3. CAN concentration effect on oxygen evolution using (left) Ge-monomer and (right)
Ge-dimer. CAN concentration: (green) 18 mM, (red) 12 mM, (blue) 6 mM, (black) 3
mM Ru concentration: 60 PM, CAN concentration: 6 mM in 100 mL of 0.1 M HNO3.
Fig 3 shows effect of CAN concentration on the oxygen evolution rate. Initial reaction rate
decreased by decreasing CAN concentration in the case of Ge-monomer which agreed withresult reported by Fukuzumi group [2]. On the other hand, intial reaction rate did not change
by decreasing CAN concentration in the case of Ge-dimer. This result indicate that reaction
mechanism of dimer is different from reaction mechanism of monomer.
References [1] Miras, H. N.; Yan, J.; Long, D.-L.; Cronin, L. Chem. Soc. Rev. 2012, 41, 7403.
[2] Murakami, M.; et al. J. Am. Chem. Soc. 2011, 133, 11605.
[3] Sadakane, M.; et al. Dalton Trans. 2007, 2833.

̶ 38 ̶

The excited states of the inactive and active forms of the Orange
Carotenoid Protein
Rudi Berera1, Michal Gwizdala2,3, Ivo HM van Stokkum1, Diana Kirilovsky2,3
and Rienk van Grondelle1
1 Division of Physics and Astronomy, Department of Biophysics, VU University Amsterdam,
The Netherlands
2 Commissariat a l’Energie Atomique, Institute de Biologie et Tecnologie de Saclay and3Centre National de la Recherce Scientifique, 91191 Gif sur Yvette, France

Too much light in photosynthesis is just an example of how too much of a good thing can be
extremely harmful. In fact while light is the lifeblood of the photosynthetic process, too muchof it can be lethal. In order to cope with the deleterious effects of excess illumination
photosynthetic organisms have developed photoprotective mechanisms generally known as
nonphotochemical quenching (NPQ).
The orange carotenoid protein (OCP) is a crucial player in NPQ in a large number of
cyanobacteria. This water soluble protein binds one pigment only, the keto carotenoid
3’-hydroxyechinenone and needs to be photoactivated by strong (blue-green) light in order toinduce energy dissipation within or from the phycobilisome, the main light harvesting systemof these organisms. We performed transient-absorption spectroscopy on OCP samples frozen
in the inactive and active forms at 77 K. By making use of target analysis we determined theexcited state properties of the active form. Our results show that OCP photoactivation
modifies the carotenoid excited state energy landscape. More specifically the photoactivated
OCP is characterized by one state with predominantly ICT character (ICT/S1) and a lifetime of
2.3 ps, and another state with mainly S1 character (S1/ICT) with a lifetime of 7.6 ps. We also
show that the kinetic model is fully consistent with the RT data obtained earlier(1). We
propose that this ICT/S1 state acts as the quencher in the OCP mediated NPQ.
1.

Berera, R., van Stokkum, I. H. M., Gwizdala, M., Wilson, A. l., Kirilovsky, D., andvan Grondelle, R. (2012) The Photophysics of the Orange Carotenoid Protein, aLight-Powered Molecular Switch, The Journal of Physical Chemistry B 116,
2568-2574.

̶ 39 ̶

Molecular Functions of the Membrane-Extrinsic Subunits of
Photosystem II in Higher Plants    
Kentaro Ifuku
Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan / JST-PRESTO
Abstract:
Photosystem II (PSII) is a light-driven water–plastoquinone oxidoreductase and a major
source of energy on earth. Recently, the crystal structure of PSII from thermophilic
cyanobacteria was resolved at atomic resolution, which allows us to analyze and understandits functions in great detail [1]. However, the structural information of cyanobacterial PSII
cannot be necessarily generalized to PSII of other eukaryotes, because eukaryotic PSII has
developed specific subunits during evolution. In particular, the compositions of the PSII
membrane-extrinsic subunits, which are associated with the luminal side of PSII and involvedin oxygen evolution, are significantly different among the oxygenic photosynthetic organisms.
The PsbP and PsbQ protein are PSII extrinsic subunits characteristically developed in green
plants and required for Ca2+ and Cl- retention in PSII, essential cofactors for water-splitting
reaction [2]. We have characterized molecular functions of PsbP and PsbQ in higher plants
and suggest that PsbP, but not PsbQ, is essential for the oxygen-evolving activity [3]. In vitro
reconstitution and cross-linking experiments suggest that PsbP directly interacts with thecytochrome b559 ! subunit of PSII (PsbE protein), and the conserved His-144 residue in thecentral !"! structure of PsbP has a critical role to maintain this interaction [4]. The
substitution of His-144 to alanine particularly lowered the Cl--retention ability of PsbP,
suggesting that the interaction between PsbP and PsbE is required for the optimal PSII
activity. Molecular evolution and the specific role of PsbP in regulating the function of the
PSII-light-harvesting complex II supercomplex will be discussed.
References:[1] Umena, Y.; Kawakami, K.; Shen, J.-R.; Kamiya, N. Nature. 2011, 473, 55-60.
[2] Ifuku, K.; Ido, K.; Sato, F J. Photochem. Photobiol. B. 2011, 104, 158-164.
[3] Kakiuchi, S.; Uno, C.; Ido, K.; Nishimura, T.; Noguchi, T.; Ifuku, K.; Sato, F. Biochim.
Biophys. Acta (Bioenergetics) 2012, 1817, 1346-1351.
[4] Ido, K.; Kakiuchi, S.; Uno, C.; Nishimura, T.; Fukao, Y.; Noguchi, T.; Sato, F.; Ifuku, K.
J. Biol. Chem. 2012, 287, 26377-26387.

̶ 40 ̶

Proton transfer mediated by hydrogen bonds in proteins    
Hiroshi Ishikita1,2(1) 202 Building E, Career-Path Promotion Unit for Young Life Scientists, Graduate
School of Medicine, Kyoto University, Yoshida-Konoe-cho, Sakyo-ku, Kyoto 606-8501,
Japan(2) Japan Science and Technology Agency (JST), PRESTO, 4-1-8 Honcho Kawaguchi,
Saitama 332-0012, Japan
Abstract:
In a protein environment, protons can be transferred along a proton transfer pathway, where
each ionizable or polar site is arranged at a hydrogen-bond (H-bond) distance. Thus,
formation of an H-bond between proton donor and acceptor moieties is essential for protontransfer.

Fig 1. Potential-energy profiles of standard H-bond (left), low-barrier H-bond, LBHB (middle), and single-well
H-bond (right).

In photoactive yellow protein (PYP), the H-bond between Glu46 and p-coumaric acid is astandard H-bond in the ground state. Upon photo-excitation, the H-bond becomes anunusually short, single-well H-bond (Fig 1),
facilitating proton transfer (Fig 2) [1, 2].
Formation of a single-well H-bond has also
been observed in proton-coupled electrontransfers via quinone in the O2-evolving
complex, Photosystem II [3]. Formation of asingle-well H-bond appears to be prerequisite
for proton transfer events in proteins.
Fig 2. Formation of a single-well H-bond in PYP.

References:[1]
K. Saito and H. Ishikita, Proc Natl Acad Sci U S A 109 (2012) 167-172.
[2]
K. Saito and H. Ishikita, Biochim Biophys Acta 1827 (2013) 387-394.
[3]
K. Saito, A.W. Rutherford and H. Ishikita, Proc Natl Acad Sci U S A 110 (2013)954-959.

̶ 41 ̶

Structure of photosystem II and the mechanism of light-induced
water-oxidation
Jian-Ren Shen
Graduate School of Natural Science and Technology/Fuculty of Science,
Okayama University, Okayama 700-8530, Japan
Photosystem II is a multi-subunit membrane protein complex containing 19-20 subunits
with a total molecular mass of 350 kDa, and forms a dimer in cyanobacterial cells. PSII
catalyzes light-induced water splitting, leading to the evolution of molecular oxygen. The
catalytic center of water-oxidation is a Mn4CaO5-cluster. In this talk, I will introduce the highresolution structure of PSII analyzed at a resolution of 1.9 Å [1], with the emphasis on the
structure of the oxygen-evolving complex (OEC), which is organized in a distorted chair form
with a cubane-like structure. The cubane-like core of the metal cluster is composed of
Mn3CaO4 linked via µ-oxo bridges to a fourth Mn (Mn4) outside of the cubane. The distortionin the cubane structure makes it unstable, or flexible, which may be important for the
structural changes to occur accompanying the water-oxidation cycle, namely, the S-state cycle.
In order to examine the role of the only Ca2+ ion within the cubane core, we replaced it with
Sr2+, and analyzed its structure [2]. Our analysis showed that the structure of the resulted
Mn4SrO5-cluster is very similar to that of the Mn4CaO5-cluster. However, among the twowater molecules W3 and W4 ligated to the Ca2+ ion, the position of W3 was affected by theSr2+-substitution, leading to an elongated distance between W3 and Sr2+ as well as that of
W2-W3; whereas the position of W4 was not much affected. This result suggests that W3
binds to Ca2+ more weakly than W4, and is more mobile than W4. The change in the positionof W3 may therefore be one of the reasons for the decrease in the oxygen-evolving activity
upon Sr2+-substitution, which implies the possible involvement of this water in the O-O bondformation.
This work was performed in collaboration with Yasufumi Umena, Keisuke Kawakami, Fasal
Hammad Mekky Koua, and Nobuo Kamiya. I thank them for their great contributions.
References[1] Umena Y., Kawakami K., Shen J.-R., Kamiya N. Nature 2011, 473, 55-60.
[2] Koua K.M.H., Umena Y., Kawakami K., Shen J.-R. Proc. Natl. Acad. Sci. USA 2013, inpress.
̶ 42 ̶

Wednesday, 6th March̶ 43 ̶

̶ 44 ̶

Artificial Photosynthesis Using Homogeneous andHeterogeneous Photocatalytic Systems.

Osamu Ishitani
Department of Chemistry, Tokyo Institute of Technology, Japan
Abstract: Both the problems of the global warming and shortage of the fossil fuels havebrought about great interest in photochemical utilization of CO2 with solar energy.
Efficient photocatalysts for CO2 reduction must be necessary for development of such animportant technology.
We have developed novel types of photocatalytic systems using metal complexes
and/or semiconductors as a photocatalyst.1
I will focus on the following systems in mypresentation.
(1)
Architecture of supramolecular photocatalysts driven with visible light, which canefficiently reduce CO2 selectively to CO or HCOOH.2-6(2) Z-scheme type photocatalysts by using hybrids composed with the supramolecular
photocatalyst and a semiconductor, which can reduce CO2 with methanol as an electron
donor.

̶ 45 ̶

References:
1. Yui, T.; Tamaki, Y.; Sekizawa, K.; Ishitani, O., Photocatalytic reduction of CO2: frommolecules to semiconductors. Top. Curr. Chem. 2011, 303, 151-84.
2. Gholamkhass, B.; Mametsuka, H.; Koike, K.; Tanabe, T.; Furue, M.; Ishitani, O. Inorg.
Chem. 2005, 44, 2326.
3. Sato, S.; Koike, K.; Inoue, H.; Ishitani, O. Photochem. Photobiol. Sci. 2007, 6, 454.
4. Koike, K.; Naito, S.; Sato, S.; Tamaki, Y.; Ishitani, O. J Photochem. Photobiol. A: Chem.
2009, 207, 109.
5. Tamaki, Y.; Watanabe, K.; Koike, K.; Inoue, H.; Morimoto, T.; Ishitani, O. Faraday
Discuss. 2012, 155, 115.
6. Tamaki, Y.; Morimoto, T.; Koike, K.; Ishitani, O. Proc. Natl. Acad. Sci. USA 2012, 109,
15673.

̶ 46 ̶

Molecular design of catalysts for water oxidation
taward artifitial photosynthesis.
   
Masayuki Yagi
Department of Materials Science and Technology, Faculty of Engineering and Center forTransdisciplinary Research, Niigata University, 8050 Ikarashi-2, Niigata 950-2181, Japan
 PRESTO, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama
332-0012, Japan
Ruthenium(II) complexes with polypyridyl ligands have been extensively studied becauseof diverse variety of excited-state phenomena, including photoluminescence, photoredox
chemistry, and photosubstitution process. The luminescent excited state is usually a triplet
metal-to-ligand charge transfer (3MLCT) state. In some case, thermal excitation of 3MLCT is
known to allow a triplet ligand field (3d-d) excited state, and the latter state is assumed to be
involved in a dissociative mechanism for photosubstitution. Recently, much attention has
been given to poly(pyridyl)ruthenium aquo complexes as water oxidation catalyst. Most ofthese complexes undergo proton coupled electron transfer reactions to give RuV=O species
which have been pointed out as a key intermediate in the catalytic cycle of water oxidation.
One could expect that dinuclear ruthenium complexes capable of being intramolecular
coupling of RuV=O moieties work as a highly water oxidation catalyst. We design a new
dinuclear ruthenium complex (denoted as Ru2, see Fig.1) shown in the below scheme.
However, the thermochemical reaction of Ru(tpy)Cl3 with the bridging ligand (L) having ananthridine moiety selectively produces trans-[Ru(tpy)(L)Cl]+ (trans-RuLCl). The subsequent
reaction of trans-RuLCl with additional Ru(tpy)Cl3 can not give Ru2 due to the sterichindrance between tpy ligands on trans-RuLCl and Ru(tpy)Cl3 To overcome the problem on
the thermochemical synthesis, we focus on the utilization of photoisomerization reactions ofpoly(pyridyl)ruthenium(II) aquo complexes which was recently reported in our earlier
paper.[1]The thermochemical reaction of L and Ru(tpy)Cl3 in water gave a green solid oftrans-RuLCl, which is identified from single X-ray crystallography and NMR data.
trans-[Ru(tpy)(L)OH2]2+ (trans-RuLH2O) was obtained by reflux with AgNO3 in water. Next,
the aqueous solution of trans-RuLH2O was irradiated with visible light to givecis-[Ru(tpy)(L)OH2]+ (cis-RuLH2O). The photoisomerization reaction was monitored by
UV-vis and 1H NMR spectroscopy techniques, and the4+quantum yield of the reaction was 4.6 ! 10-2 %. Ru2 wasNNsynthesized by the following two methods. (1) It was givenNRufrom the reaction of cis-RuLH2O with 1 equivalent of
N N
H2O
Ru(tpy)Cl3 by reflux with microwave radiation (yield 20 %)NR
H2O(2) It was also given by one-pod synthesis, where
N N
Ru(tpy)Cl3 and L were irradiated with visible light at 70°C
N Ru
N
followed by the reflux with microwave radiation for 30 min.
N(yield 16 %). Ru2 was characterized by mass spectroscopic
data, exhibiting a peak at m/z = 371.98 which can be assigned
cis,cis-[{Ru(tpy)(OH2)}2L]4+
to [RuII2(tpy)2L(OH)(OH2)]3+ (m/z = 372.05). The 1H and Fig. 1 Structure of a dinuclear1
H-1H COSY NMR data suggest a high symmetricruthenium complex.
configuration of cis,cis-[RuII2(tpy)2L(OH)(OH2)]3+ in D2O.
[1]

Yamazaki, H.; Hakamata, T.; Komi, M.; Yagi, M. J. Am. Chem. Soc. 2011, 133,
8846-8849.

̶ 47 ̶

Redox Behavior of High-Valent Polynuclear ManganeseComplexes with Xanthene-Bridged Schiff Base Ligands    
Masakazu Hirotsu
Graduate School of Science, Osaka City University, Osaka, 558-8585, Japan
Photosynthetic water oxidation is catalyzed by the oxygen evolving complex (OEC)containing a manganese cluster in photosystem II (PSII). X-ray diffraction studies of PSII
revealed that the active site of the OEC has a Mn4CaO5 cluster [1]. Biomimetic manganesecomplexes for the OEC have not been fully established. We recently developed axanthene-bridged Schiff base ligand, H4L, which effectively forms tetranuclear manganesecomplexes (Scheme 1) [2]. Redox behavior of the tetramanganese complexes supported by
the xanthene-bridged ligands is presented.
The reaction of H4L with 2 equiv of Mn(OAc)2·4H2O under reflux in ethanol afforded themixed-valence MnII2MnIII2 complex [Mn4(L)2(µ-OAc)2] (1), which has an incomplete
double-cubane structure of Mn4O6 with four alkoxide and two phenolate O atoms. The
analogous reaction using MnCl2·4H2O gave the chloride-bridged MnIII4 complex[Mn4(L)2Cl3(µ4-Cl)(OH2)] (2). The xanthene-bridged ligand L has a propensity to incorporate
fourmanganeseionsbydimerization.
When
Mn(OAc)3·2H2Oor[Mn12O12(OAc)16(OH2)4]·2AcOH4H2O was used as a starting manganese complex withhigher oxidation states, the MnIII4 complex [Mn4(L)(HL)(µ3-O)(µ-OAc)2](BF4) (3) was
obtained. Complex 3 has a bridging oxide ligand and a non-coordinated propanol arm of HL,
and its Mn4O6 core structure is similar to that of 1.
Cyclic voltammogramsof 1 and 3 in CH2Cl2 exhibit
four redox processes in therange of –1.2 to 0.7 V vsEo’(Fc+/0). The oxide-bridged
complex 3 stabilizes higher
oxidation states comparedwith 1. Reduction of 3 gave 1
through proton abstraction
from the non-coordinatedpropanol arm by the bridging
oxide ligand.
Scheme 1. Synthesis of Manganese Complexes[1] Umena, Y.; Kawakami, K.; Shen, J.-R.; Kamiya, N. Nature 2011, 473, 55.
[2] Hirotsu, M.; Shimizu, Y.; Kuwamura, N.; Tanaka, R.; Kinoshita, I.; Takada, R.; Teki, Y.;
Hashimoto, H. Inorg. Chem. 2012, 51, 766.

Construction of Photochemical Hydrogen Evolution
Systems Based on the Effective Utilization of 3d Metals
Masako Kato
Department of Chemistry, Faculty of Science, Hokkaido University,
Sapporo 060-0810, JapanThe strategy of our group to contributeH2
H2
Hto the energy issues is to construct novel
–H
–H
N
N
N
–e
–e
M
M
M
photocatalytic systems using common
N
N
N
+H
+H
H2
H
H
+e
+e
metals instead of precious metals. For thissemi-Benzoquinodiimine
Benzoquinodiimine
challenging subject, we developed metal o-Phenylenediamine(opda)(s-bqdi)(bqdi)
complexes containing redox active ligands
Scheme 1. Multi-step redox propeties ofsuch as benzenedithiolato and catecholato M-opda complexes.
ions [1]. As shown in Scheme 1,o-phenylenediamine (opda) also acts as a redox active ligand taking part in the multiple
proton/electron transfer of the metal complexes. By using this ligand, we found a simple
metal-complex system for photochemical hydrogen evolution without extra photosensitizers.
On photoirradiation with the UV light, the hydrogen evolution occurred from the suspension
formed by the mixing of Fe(ClO4)2 and opda in THF. It is clear that the complexation of Fe
ion and opda is essential for the reaction because very little hydrogen was evolved in theabsence of Fe(II) ion. The hydrogen molecules would be produced by the photochemical
activation of opda coordinated to Fe (II)ion. Interestingly, the hydrogen evolution
increased by adding hydroquinone (HQ)
indicating that the catalytic processproceeded by the supply of both protons
and electrons from HQ as shown in
Scheme 2. The results demonstrate a novel
photoinduced hydrogen production/storage
Scheme 2. Proposed photocatalytic hydrogensystemcomprisedofcompletely evolution cycle.
precious-metal free materials.
+

+

–

–

+

+

–

–

References:[1] Matsumoto, T.; Chang, H.-C.; Kobayashi, A.; Uosaki, K.; Kato, M. Inorg. Chem. 2011, 50,
2859-2869; Matsumoto, T.; Wakizaka, M.; Yano, H.; Kobayashi, A.; Chang, H.-C.; Kato, M.
Dalton Trans. 2012, 41, 8201–8478.

̶ 49 ̶Development of Visible-Light-Responsive
Photocatalysts for Solar Hydrogen Production    
Ryu AbeDepartment of Energy and Hydrocarbon Chemistry, Graduate School of Science and Engineering,
Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan. email: ryu-abe@scl.kyoto-u.ac.jp

Photocatalytic water splitting into H2 and O2 using a semiconductor photocatalyst hasreceived much attention recently due to the potential of this method for the clean productionof H2 from water utilizing solar energy.[1, 2] Although a number of metal oxides have beenreported to be active photocatalysts for the water-splitting reaction, most only function underultraviolet (UV) light (! < 400 nm) owing to the large band gap energy of the materials (> 3eV). Because almost half of all incident solar energy at the Earth’s surface falls in thevisible region (400 < ! < 800 nm), the efficient utilization of visible light remains
indispensable for realizing practical H2 production based on photocatalytic water splitting.
However, it is intrinsically difficult to develop an oxide semiconductor having both asufficiently narrow bandgap (< 3.0 eV)
allowing visible light absorption and ahighly negative conduction band level forH2 production. In order to split water
under visible light, we have developed new
type of water splitting system based on
two-step photoexcitation between two
different photocatalyst materials, as shown
Fig. 1. Conceptual scheme for two-step waterin Fig. 1. This process was inspired by splitting
natural photosynthesis in green plants and is known as the Z-scheme. In two-step systems,
the water splitting reaction is broken up into two stages: one for H2 evolution and the other forO2 evolution; these are combined by using a shuttle redox couple (Red/Ox) in the solution.
Over a H2 evolution photocatalyst (referred to as a H2 photocatalyst), the photoexcitedelectrons reduce water to H2 and holes in the valence band oxidize the reductant (Red) to anoxidant (Ox). The oxidant is reduced back to the reductant by photoexcited electrons
generated over an O2 evolution photocatalyst (referred to as an O2 photocatalyst), where theholes oxidize water to O2. This system lowers the energy required for photocatalysis,
allowing visible light to be utilized more efficiently than in conventional water-splitting
systems. In other words, it enables a semiconductor to be used that has either a water
reduction or oxidation potential on one side of the system.
For example,
visible-light-responsive oxides such as WO3 can be used as O2 photocatalysts if they can
reduce the oxidant to a reductant. Similarly, non-oxide photocatalysts (e.g., sulfides,
oxynitrides, and dyes) can be used as H2 photocatalysts if they can oxidize the reductant to an̶ 50 ̶

oxidant. Based on the strategy, we have achieved overall water splitting using various
visible light responsive photocatalysts, such as SrTiO3 doped with Cr,[3] tantalum oxynitrides(TaON or BaTaO2N),[4-7] and organic dyes,[8] which work as a H2 evolution photocatalyst,
combined with tungsten oxide (WO3) for O2 evolution in the presence of a shuttle redox
mediator such as iodate/iodide (IO3–/I–). The use of BaTaO2N or coumarin organic dye wasdemonstrating to be photoactive at wavelength up to ca. 700 nm. These results demonstrate
the potential of a two-step water-splitting system for utilizing a broader band of visible
spectrum.
Some oxynitride materials possess appropriate band levels for water splitting as well as anarrow band gap that permits visible light absorption. The top of valence band of these
oxynitrides is much more negative than those of the corresponding oxides due tohybridization of the N 2p and O 2p orbitals. On the other hand, the bottom of the conduction
band in these tantalum oxynitrides consists predominantly of empty tantalum orbitals. For
example, tantalum oxynitride (TaON; band gap: ca. 2.5 eV, corresponding to light absorption
up to 500 nm) has conduction and valence band edges at ca. -0.3 and +2.2 V vs. NHE,
respectively, which are suitable for both water reduction and oxidation. However, theintroduction of N 2p orbitals in the valence band generates a new problem in stability thatneed to be solved. Most oxynitrides undergo self-oxidative deactivation some degree, inwhich photogenerated holes oxidize nitrogen anions (N3–) to N2 (2N3– + 6h+ ! N2).
Recently, we have developed a simple method for fabricating an efficient oxynitride TaON, inwhich the TaON particles are first deposited on a conductive substrate using electrophoretic
deposition, and then a necking treatment is applied to form effective contacts between the
TaON particles.[9] It was also demonstrated that highly dispersed CoOx nanoparticles on the
TaON photoanode efficiently scavenge photogenerated holes and effectively suppress
self-oxidative deactivation of the TaON surface, resulting in a stable photocurrent.[10] This
enabled us to stably split water into H2 and O2 under visible light irradiation at a relatively
low applied bias (0.6 V vs. Pt counter electrode).
References:[1] Kudo, A.; Miseki, Y. Chem. Soc. Rev. 2009, 38, 253[2]Abe, R. J. Photochem. Photobiol. C: Photochemistry Reviews 2010, 11, 179.

[3]

Abe, R.; Sayama, K.; Sugihara, H. J. Phys. Chem. B 2005, 109, 16052.

[4]Abe, R.; Takata, T.; Sugihara, H.; Domen, K. Chem. Commun. 2005, 3829.

[5]

Higashi, M.; Abe, R.; Takata, T.; Domen, K. Chem. Mater. 2005, 21, 1543.

[6]

Maeda, K.; Higashi, M.; Lu, D.; Abe, R.; Domen, K. J. Am. Chem. Soc. 2010, 132, 5858.

[7]Abe, R.; Higashi, M.; Domen, K. ChemSusChem. 2011, 4, 228.

[8]

Abe, R.; Shinmei, K.; Hara, K.; Ohtani, B. Chem. Commun. 2009, 3577.

[9]Abe, R.; Higashi, M.; Domen, K. J. Am. Chem. Soc. 2010, 132, 11828.

[10]

Higashi M.; Domen K.; Abe, R. J. Am. Chem. Soc., 2012, 134, 6968.
̶ 51 ̶

 Theoretical Study of Charge Transfer Process
in Condenced Matter    
Toshio Asada

Osaka Prefecture University, The Research Institute for MolecularElectronic Devices (RIMED)
1-1, Gakuen-cho, Naka-ku, Sakai-city, Osaka, 599-8531 Japan
Abstract:.
The simulation of chemical processes in proteins, condenced materials, and solutions
require the coupling of quantum chemical methods and statistical mechanics approaches. The
computatational code[1] has been developed for molecular dynamics (MD) simulations using
combined quantum mechanical/molecular mechanical (QM/MM) methods. Using the
program, physical properties relating to charge transfer processes in complexes such as thedegradation mechanism of the electron transporting layer in organic light-emitting diode(OLED)[2] or environmental effects on the redox potential of QB plastoquinone inphotosystem II (PSII) have been investigated.

Organic electro-luminescent (EL) and OLED electronic devices have recently been usedas displays in mobile phones, televisions, electronic papers, and organic EL illuminations. In
these OLED displays, emission is triggered by charge recombinations of electrons and holes
in the light-emitting layer. It is known that the light emission efficiency of OLED devices isreduced as a function of time. This phenomenon is usually explained by penetration of Li ions
into the electron-transporting layer. The degradation mechanism of the electron-transporting
layer of Alq3 is theoretically investigated [2] based on charge transfer rate constants.
The redox potential is also important to explain the charge transfer pathways in proteins.
The environmental effects on the redox potential is evaluated using QM/MM MD simulations
which can take the dynamical effects into consideration. Theoretical evalutaion of redox
potentials of QB, and of the bromacil in PSII will be discussed.

References:[1] Okamoto, T.; Yamada, K.; Koyano,Y.; Asada,T; Koga,N.; Nagaoka,M.; J.Comp.Chem.
2011, 32, 932-942.
[2] Asada ,T.; Ohta,K.; Koseki,S.; Theo.Chem.Acc. 2011, 130, 439-448.

̶ 52 ̶

Bioelectrochemical Approach in Energy Conversion    
Kenji Kano
Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto
University, Japan
Bioelectrocatalytic systems, in which several biological redox reactions are coupledwith electrode reactions, may be utilized for bio-sensing and energy conversion systems. Oneof the most popular biosensors is commercially available blood glucose sensor. On the other
hand, biofuel cell becomes attracting attention as one of next-generation energy conversion
systems. In order to couple biological redox reactions with electrode reactions, there are two
types of strategies; direct electron transfer (DET)-type communication without mediator andmediated electron transfer (MET)-type one with mediators to assist the electron trasnfer
between biological redox function and electrode.
Multi-copper oxidases (MCO) including laccase, bilirubin oxidase, and copper efflux
oxidase would be the best catalyst for oxygen-reducing cathodes without release of
O2-derived intermediates. The current density of DET-type bio-cathode has reached about 40
mA cm–2 at 0 V (vs. Ag|AgCl electrode) at pH 5 under passive mode in atmosphere bycontrolling the hydrophobicity for oxygen transport and hydrophilicity for enzymatic reactionof meso-porous carbon electrodes.
On the other hand, there are a wide variety of strategies for anode. One of simple
bio-anodes is microbe-catalyzed one, in which several microbes such as Shewanella sp. may
be utilized to oxidize several organic and inorganic compounds and the electron is tranferredto the cathode preferably in DET mode. This system is called microbial fuel cell (MFC). The
weak points of this system is the low current density and that some inorganic cathodecatalysis including specific carbon material such as Co-containing graphene will be required
for field-type MFCs.
Photo-current can be observed in the presence of cyanobacteria as a catalyst andquinone as a mediator in anode on usual materials, and the coupling of the photo-anodesystem with MCO-catalyzed cathode leads to a bio-solar system, which can convert thephoto-energy into the electric energy.
Glucose/O2 biofuel cell has also been constructed in cooperation with Sony.
NAD-dependent glucose dehydrogenase/NAD/diaphorase/quinone system is utilized as an
anode catalyst. The cell power has reached about 10 mW cm–2, which is the world record in
the MET system. Fructose/O2 biofuel cell works as a noble DET-type biofuel cell, in which
membrane-bound fructose dehydrogenase is utilized as an anode catalyst. The cell power has
reached 2 mW cm–2, which is also the world record in the DET system.
The weak point of these enzymatic sugar/O2 fuel cells may be that the complete
oxidation of sugar fuels is difficult. In this sense, hydrogen and formate may be utilized as
̶ 53 ̶

fuels for complete oxidation. Hydrogen oxydation can be accelerated by Desulfovibrio
vulgaris (Hildenborough) as a catalyst and methyl viologen as a mediator. The true mediator
is of course hydrogenase. The H2-reducing anode has been coupled with MCO-catalyzed
cathode to constuct an H2/O2 biofuel cell. Electrochemistry of isolated hydrogenase is also
receiving a great attention.
Membrane-bound [NiFe] hydrogenase gives DET-type H2-oxidation current. The
activity is reversibly inhibited at positive potential. However, the system may be utilized toconstruct gas-diffusion DET-type H2/O2 biofuel cells.
Soluble NAD+-reducing hydrogenase and W- or Mo-containing NAD+-linked
formate dehydrogenase has sequence homology very close to that of complex I. These arealso useful to construct hydrogen-oxidizing and formate-oxidizing anodes, respectively.
These variety of anode strategies for energy conversion system are also very
important to construct biosensors.

̶ 54 ̶

Solar Fuel Production Based on the Bio-hybrid
Artificial Photosynthesis SystemYutaka Amao
Department of Applied Chemistry, Oita University, Oita 870-1192, Japan, and Precursory
Research for Embryonic Science and Technology (PREST), Japan Scienceand Technology Agency (JST), 4-1-8 Honcho Kawaguchi, Saitama 332-0012, Japan
Abstract: Major purpose of this presentation is to achieve the “Artificial Photosynthesis for
Solar Fuel Production”. In this presentation, production technologies of low-carbon fuels areclassified into two categories[1-3]. First category is the solar hydrogen production from water
based on the artificial photosynthesis using bioinspired system consisting of an electron donor,
a photosensitiser, an electron relay and a platinum nano-particle. Second category is theartificial photosynthesis system for solar fuel production from CO2. CO2 fixation is a potential
technology for photocatalytic CO2 reduction and synthesis of organic compounds from CO2
as the starting material. For example, the low-carbon fuel, methanol production from CO2 isaccomplished using the artificial photosynthesis system consisting of the photosensitizer
molecule and three dehydrogenases (formate, aldehyde and alcohol dehydrogenases). For
example, methanol production from CO2 using the artificial photosynthesis system is
introduced. A sample solution containing ZnTPPS (0.1 !M), MV2+ (0.1 mM), TEOA (0.3 M)
FDH (12.5 units), AldDH (12.5 units) and ADH (12.5 units) is deaerated and then flushedwith argon gas for 5 min. NaHCO3 (0.01 mM) is added to the sample solution and thenirradiated. The produced methanol is measured by gas chromatography. When the sample
solution is irradiated with a tungsten lamp, methanol is produced with irradiation time. The
methanol production was 0.55 µM after 4 h irradiation. The conversion yield of HCO3- tomethanol is estimated to be 5.5% after 4 h irradiation. In contrast, no methanol production isobserved without irradiation or in the absence of HCO3-. Thus, the produced methanol is not
the oxidized TEOA but the origin from HCO3- reduction with three dehydrogenases. These
results indicate that the photochemical synthesis of methanol from HCO3- with FDH, AldDH
and ADH via the photoreduction of MV2+ using ZnTPPS photosensitisation.
References:[1] Amao, Y. ChemCatChem 2011, 3, 458.
[2] Amao, Y. Current Nanoscience 2008, 4, 45.
[3] Amao, Y., Maki, Y., Fuchino, Y. J. Phys. Chem. C 2009, 113, 16811.

̶ 55 ̶

̶ 56 ̶

Poster Presentations

̶ 57 ̶

Titles of Poster Presentations
PS01. Mutual relationships between structural and functional changes in the
PsbM-deletion mutant of photosystem II
Sayaka Utoh, Keisuke Kawakami, Yasufumi Umena, Masako Iwai, Masahiko
Ikeuchi, Jian-Ren Shen, Nobuo Kamiya
PS02. Theoretical Simulation of Carotenoid Absorption Spectrum
Chiasa Uragami, Hideki Hashimoto
PS03. Three catalysis achieved by ADP ribose pyrophosphatase
Yoshihiko Furuike, Yuka Akita, Ikuko Miyahara, and Nobuo Kamiya
PS04. Synthesis of a sugar-incorporated C-C-N pincer palladium complex andtheir catalytic ability toward Suzuki-Miyaura reaction in water
Yosuke Imanaka, Hideki Hashimoto, Isamu Kinoshita, and Takanori Nishioka
PS05. Reactions of Dibenzothiophene Derivatives Containing Bidentate Chelate
Moieties with Iron Carbonyl Complexes
Kiyokazu Santo, Masakazu Hirotsu, and Isamu Kinoshita
PS06. Dynamic structure change of phenothiazine trimer radical cation in its
photo-induced charge separated state
Ayumu Karimata
PS07. Molecular assembly of photosynthetic antenna pigment complexes on a gold
electrode by using recombinant light-harvesting polypeptides with His-tag
Syunsuke Sakai
PS08. Pigments and protein composition of the photosynthetic antenna from asiphonous green alga (Codium intricatum Okamura)
SHIGEMATSU, Yusuke; FUJII, Ritsuko; OKA, Naohiro; IHA, Masahiko;
HASHIMOTO, Hideki
PS09. Crystal enlargement of ADPRase and neutron diffraction experiments to
elucidate the proton transfer pathway
Yusuke Komatsu, Yoshihiko Furuike, Ikuko Miyahara, and Nobuo Kamiya
PS10. Sugar-coated N-heterocyclic carbene complexes incorporated with long alkyl
ChainsAkiya Oda, Hideki Hashimoto, Isamu Kinoshita, and Takanori Nishioka
PS11. Elucidation of the photosynthtic function of carbonylcarotenoids in
the Chloroplast Genome-Modified lettuce
Masahiro Shirota, Ritsuko Fujii, Norihiko Misawa, Hideki Hashimoto
PS12. Optical properties of photoexcited states of oceanic photosynthetic antenna
pigment, chlorophylls c (Chls c)
Naoki Senju, Ritsuko Fujii, Tadashi Mizoguchi, Masahiko Iha, Akio Ichimura,
Hideki Hashimoto
PS13. Applications of Peptide Gemini Surfactants as Novel Solubilization
Surfactants for Photosystems I and II of Cyanobacteria
S. Koeda, T. Mizuno, T. Noji, T. Dewa, T. Tanaka, M. Nango̶ 58 ̶

PS14. How iodide ions inhibit the oxygen evolution of photosystem II?
Keisuke Kawakami, Daisuke Hgiwara, Yasufumi Umena, Jian-Ren Shen,
Nobuo Kamiya
PS15. Syntheses of sulfur bridged Mo complexes with dithiophosphate ligand andthe stability controlled by functional ligand
KAWAMOTO, Keisuke; ICHIMURA, Akio; KINOSHITA, Isamu
PS16. Syntheses and Characterization of Novel Sulfido PtM2 (M = Rh, Ir) Type
Trinuclear Complexes with Chelated N-Heterocyclic Carbene Ligands
Yuri Maeda, Hideki Hashimoto, Isamu Kinoshita, and Takanori Nishioka
PS17. Exciton-exciton annihilation in light harvesting complexes from a purple
bacterum
Yuya Nagaoka, Daisuke Kosumi, Ritsuko Fujii, Mitsuru Sugisaki,
and Hideki Hashimoto
PS18. Towards Catalytic Water Oxidation: Synthesis of a Cobalt(III)-Oxon Cuban
Cluster with protected-p-pyridylphosphonato ligand
Tomoyuki HASEGAWA, Keisuke KAWAMOTO, Isamu KINOSHITA
PS19. Computational analysis of the electron-transfer inhibitors in Photosystem II
Ayako Tanaka,Satoshi Suzuri,Asada Toshio, Keisuke Kawakami,
Yasufumi Umena, Jian-Ren Shen, Miyahara Ikuko, Nobuo Kamiya
PS20. Regulation of the receptor ability of Zn-porphyrin by the formation of Fe
complexes
Yoshikazu Ninomiya, Masatoshi Kozaki, Shuichi Suzuki, Keiji Okada
PS21. Structural study on the Mn atoms in the oxygen-evolving complex of
Photosystem II by X-ray absorption techniques
UMENA, Yasufumi, KAWAKAMI, Keisuke, Tanka, Ayaka, SHEN, Jian-Ren,
KAMIYA, Nobuo
PS22. The pH titration experiment in the crystals of ADPRase-ADPR binary
complexes
Yurie Tomita, Yoshihiko Furuike, Ikuko Miyahara, and Nobuo Kamiya
PS23. Design of Polyoxometalates Aimed to Artificial Photosynthesis
Hitoshi Yoneda, Keisuke Kawamoto, Toshio Asada, Isamu Kinoshita,and Hideki Hashimoto
PS24. Synthesis and Magnetic Properties of Iron and Cobalt Complexes
Containing a !-Radical Ligand with Photo-Excited High-Spin State
Koichi Katayama
PS25. Relationship of charge of heads group of lipid and photochemical activity ofphotosystem II in reconstituted lipid bilayer
Tomoyasu Noji, Masaharu Kondo, Keisuke Kawakami, Jian-ren Shen,
Mamoru Nango, Takehisa Dewa
PS26. Construction of Carotenoid Molecularly-Oriented Film: A Model System of
Photosynthetic Antenna
Shouhei Kita

̶ 59 ̶

PS27. Photoinduced Electron Transfer of Platinum Bipyridine Diacetylides Linked
by Triphenylamine and Naphthalenediimide and its application tophotoelectric conversion system
Shuichi Suzuki, Yuma Matsumoto, Mai Tsubamoto, Masatoshi Kozaki, Kenshi
Kimoto, Munetaka Iwamura, Koichi Nozaki, Naoki Senju, Chiasa Uragami,
Hideki Hashimoto, and Keiji Okada
PS28. Syntheses and Properties of Nickel and Zinc Complexes with a Tripodal
Ligand, 1-(pyridine-2-yl)-2,2-bis(pyridine-2-ylthio)ethanone
Yu Masuda
PS29. A Trial for Developing the Hybrid Artificial Photosynthesis
Yui Takemoto, Keisuke Kawakami, Isamu Kinoshita

PS01. Mutual relationships between structural and functional changes in the
PsbM-deletion mutant of photosystem II
Sayaka Utoh1, Keisuke Kawakami2, Yasufumi Umena2,3, Masako Iwai4, Masahiko
Ikeuchi5 , Jian-Ren Shen6, Nobuo Kamiya2,11Graduate School of Science, Osaka City University; 2 The OCU Advanced ResearchInstitute for Natural Science and Technology (OCARINA), Osaka City University;
3
JST-PRESTO; 4 Center for Biological Resources and Informatics, Tokyo Institute ofTechnology; 5 Department of Life Sciences (Biology), Graduate School of Arts andScience, The University of Tokyo; 6 Division of Bioscience, Graduate School of Natural
Science and Technology/Faculty of Science, Okayama University
Photosystem II (PSII) is a membrane protein complex that performs light-induced
oxygen evolution from water. PSII consists of 20 subunits and various cofactors such as
chlorophyll a, carotenoid, plastoquinone, and lipids. PsbM is one of the low molecularweight subunits of PSII, and is located in the monomer-monomer interface of PSII
dimer. The function of PsbM has been reported to stabilize the PSII dimer and to relate
to electron transfer efficiency of PSII. In order to elucidate the role of PsbM, we
purified oxygen-evolving PSII complex from a PsbM-deletion mutant ofThermosynechococcus vulcanus, and started its structural and biochemical analysis.

PS02. Theoretical Simulation of Carotenoid Absorption Spectrum
Chiasa Uragami1, Hideki Hashimoto1,2
1. JST/CREST and Department of Physics, Graduate School of Osaka City University
2. Osaka City University Advanced Research Institute for Natural Science andTechnology (OCARINA)
In general, the absorption spectrum of carotenoid depends on its chemical structure.
However, when we compare the absorption spectrum of the !-carotene with lycopene
and astxanthin, which all of them has same number of conjugated double bond, not only
the maximum wavelength, but also the spectral shapes are obviously different. Thus, we
could see that the absorption spectra dose not depends only on the chemical structure.
There must be some other factors that make difference in spectrum. In this study weconsider that the factor is interaction between the carotenoid and neighboring molecules,
hence we theoretically simulate the absorption spectrum and tried to get some kind of
information that which kind of interaction contributes to the absorption spectrum.

̶ 61 ̶

PS03. Three catalysis achieved by ADP ribose pyrophosphatase!

Yoshihiko Furuike1, Yuka Akita1, Ikuko Miyahara1, and Nobuo Kamiya2
1

2

Graduate School of Science, Osaka City University
The OCU Advanced Research Institute for Natural Science and Technology(OCARINA), Osaka City University

ADP ribose pyrophosphatase (ADPRase) hydrolyzes ADP ribose to AMP and ribose5’-phosphate (R5P) with the help of divalent metal cations. Although the existence ofthe concerted general acid-base catalysis and the metal ion catalysis has been expected,
the detail of their chemical mechanisms hasn’t been described. In order to reveal the
ADPRase’s chemical function, we conducted the time resolved X-ray crystallography atatomic resolutions. Consequently, the ADPRase mechanism could be described in threeimportant points; the metal assisted regulations of configurations and reactivities for theelectrophilic pyrophosphate and the nucleophilic water molecule, the participation of
Glu residues in the deprotonation of the water molecule around "-phosphorus, and thewell-designed hydrogen bonding network including the low barrier hydrogen bondaround #-phosphorus.

PS04. Synthesis of a sugar-incorporated C-C-N pincer palladium complex andtheir catalytic ability toward Suzuki-Miyaura reaction in water
Yosuke Imanaka,* Hideki Hashimoto, Isamu Kinoshita, and Takanori Nishioka
Division of Molecular Materials Science, Graduate School of Science, Osaka City
University, The OCU Advanced Institute of Natural Science and Technology(OCARINA), Osaka City University
We demonstrated that the click chemistry is one of the useful methods to introduce
sugar units into NHC ligands. The obtained C-C-N pincer NHC Pd complex with anacetyl protected D-glucose unit exhibited efficient catalytic activity in the SuzukiMiyaura coupling reaction in aqueous media with excellent TON (91000) and TOF(30000 h–1). The acetylated complex, whose solubility is limited in water, should be
deprotected under the reaction condition. These results imply that the click chemistry
open a new way for the development of novel green asymmetric catalysts via
incorporation of a variety of sugar units including mono-, di-, and poly-saccharides into
metal complexes.

̶ 62 ̶

PS05. Reactions of Dibenzothiophene Derivatives Containing
Bidentate Chelate Moieties with Iron Carbonyl Complexes
Kiyokazu Santo, Masakazu Hirotsu, and Isamu Kinoshita
Department of Chemistry, Graduate School of Science, Osaka City University(Molecular Design Laboratory)
Hydrogenases are enzymes that catalyze the reversible oxidation of dihydrogen. The
active site of the [FeFe]-hydrogenase has two iron centers, a bridged-dithiolate ligand,and biologically unusual carbonyl and cyanide ligands. A Schiff base containing an
N,S-bidentate chelate moiety was synthesized by the reaction of 4formyldibenzothiophene with 2-(methylthio)aniline. The photochemical reaction of thedibenzothiophene derivative with Fe(CO)5 was performed to give two products,[{Fe(LS,C,N)(CO)2}Fe(CO)3] (1) and [{Fe(LS,C,N,S)(CO)}Fe(CO)3] (2), where L is aligand formed by C-S cleavage of the Schiff base ligand precursor. These complexes
have two iron centers, a bridged-thiolate ligand, and carbonyl ligands. Complex 2 acts
as an electro-catalyst for proton reduction in the presence of acetic acid.

PS06. Dynamic structure change of phenothiazine trimer radical cation in its
photo-induced charge separated state
Ayumu Karimata
Osaka City University
We investigated photo-induced electron transfer of anthraquinone-phenothiazine trimer
dyad (AQ-B-PTZ1-PTZ2-PTZ3) linked by bicyclo[2.2.2]octane (B) by means of picoand nano- second transient absorption spectroscopies. Irradiation of 355 nm laser-pulse
immediately gave a 620 nm band which is attributed to the spectral overlap ofanthraquinone radical anion and meta-stable edge phenothiazine radical cation (PTZ1+PTZ2-PTZ3). During 0.5-6 ns after the laser-pulse, the 620 nm band was converted to a
940 nm band that is assigned to the most stable phenothiazine trimer cation radical(PTZ1-PTZ2+-PTZ3), showing a hole-shift process with structural relaxation in thephenothiaizne trimer radical cation.

̶ 63 ̶

PS07. Molecular assembly of photosynthetic antenna pigment complexes on a gold
electrode by using recombinant light-harvesting polypeptides with His-tag
Syunsuke Sakai
Graduate School of Engineering, Nagoya Institute of Technology
The light-harvesting (LH) complexes containing reaction center (RC) from purple
bacteria capture visible and near-infrared light energy, funnel the excited energy into the
RC and convert it into charge separation with high efficiency. This energy transfer
system is very useful to develop artificial photosynthetic devices mimicking thephotosynthetic system. In this study, we produced recombinant LH apoproteins bearing
His-tag by E. coli expression system and reconstituted artificial photosynthetic
protein/pigment complexes using the recombinant LH apoproteins and Zn-porphyrinderivatives as a pigment cofactor. The reconstituted complex was immobilized on a Ninitrilotriacetic acid modified gold electrode for photocurrent measurement.

PS08. Pigments and protein composition of the photosynthetic antenna from asiphonous green alga (Codium intricatum Okamura)!SHIGEMATSU, Yusuke; FUJII, Ritsuko; OKA, Naohiro; IHA, Masahiko;
HASHIMOTO, Hideki
OCARINA/OCU; Osaka City Univ.; JST-PRESTO; South Product Inc.; JST-CREST
The protein and pigment analyses were performed to the siphonaxanthin-chlorophyll
a/b protein(SCP) isolated from mass-cultured filamentous body of the siphonous green
alga, Codium intricatum Okamura. The SCP consists of three 27 kDa homogeneous
subunits, which binds both siphonaxanthin and its C12:0 ester equivalently. The aminoacid sequence of SCP was partially determined. As its consequence, the SCP is quite
similar to the major photosynthetic antenna of higher plants, LHCII, except that it binds
siphonaxanthin as a substitute of lutein.

̶ 64 ̶

PS09. Crystal enlargement of ADPRase and neutron diffraction experiments to
elucidate the proton transfer pathway
Yusuke Komatsu1, Yoshihiko Furuike1, Ikuko Miyahara1,2, and Nobuo Kamiya1,21Department of chemistry, Graduate School of Science, Osaka City University; 2TheOCU Advanced Research Institute for Natural Science and Technology (OCARINA),
Osaka City University
ADPRase is a divalent-metal dependent enzyme which hydrolyzes ADP-ribose(ADPR) to AMP and ribose-5’-phosphate (R5’P). Our group has proposed a reaction
mechanism of ADPRase based on the in situ observations of crystalline-state reaction.
In order to prove the proton transfers predicted in the steps, we planned time-resolved
neutron crystallography of ADPRase-ADPR system triggered by Mn2+ soaking.
In order to experiment time-resolved neutron crystallography, we have to solve 3
problems.
1. Enlargement of ADPRase crystal 0.3mm3 at least.
2. Replacement water to deuterium in ADPRase crystal.
3. The condition for Mn2+ soaking should be examined in it.
Solve these problems, We experiment time-resolved neutron crystallography.

PS10. Sugar-coated N-heterocyclic carbene complexes incorporated with long alkyl
ChainsAkiya Oda, Hideki Hashimoto, Isamu Kinoshita, and Takanori Nishioka
Department of Chemistry, Faculty of Science, Osaka City University, Division of
Molecular Materials Science, Graduate School of Science, Osaka City University, The
OCU Advanced Institute of Natural Science and Technology (OCARINA), Osaka City
University
A palladium complex was synthesized using an NHC ligand precursor having anacetyl-protected b-D-glucopyranosyl unit and a dodecyl group. There are two possible
isomers due to arrangement of two NHC moieties and the ethylene bridge. 1H NMR
spectrum of the complex indicates that two diastereomers of the palladium complex
exist in solution. Since deprotection of the acetyl groups is essential for higher watersolubility, a reaction of the palladium complex with sodium methoxide in methanol was
also performed. Deprotection was confirmed using 1H NMR spectroscopy andelectrospray mass spectrometry. Isolation of the deprotected complex is currently inprogress.

̶ 65 ̶

PS11. Elucidation of the photosynthtic function of carbonylcarotenoids in
the Chloroplast Genome-Modified lettuce
Masahiro Shirota 1 , Ritsuko Fujii 2,3, Norihiko Misawa 4, Hideki Hashimoto 5
1

Department of Physics, Science, Osaka City University, 2 OCARINA, 3 JST-PRESTO, 4
Ishikawa Prefectural College, 5 JST-CREST

In photosynthetic pigment protein complexes, carotenoids absorb sunlight and transfer
it to chlorophylls. The high efficiency of the energy transfer has been reported for thephotosynthetic antenna from some marine algae whichbounds unique carbonyl carotenoids.1),2) Misawa et al. developed the chloroplastgenome modified (CGM) lettuce which accumulates carbonyl carotenoids in 95% of
total carotenoids. 3) The CGM lettuce grows in normal irradiation
conditions, however the function of those carbonyl carotenoids has not been clarified
yet. In this work, we prepared the major photosynthetic pigment protein complexes
from the CGM lettuce and investigated the carotenoid to chlorophyll energy transfer.
Reference
1) Polívka and Sundström, Chem. Rev. 104 (2004) 2021
2) Kosumi et al., J. Phys. Chem. Lett., 3(2012) 2659
3) N.Misawa et al, patent pending 2012-198865

PS12. Optical properties of photoexcited states of oceanic photosynthetic antenna
pigment, chlorophylls c (Chls c)
Naoki Senju1Ritsuko Fujii2,3Tadashi Mizoguchi4Masahiko Iha5Akio
Ichimura2Hideki Hashimoto1,2,6
1

2

Department of Physics, Graduate School of Science, Osaka City University,
OCARINA, 3JST-PRESTO, 4Department of Bioscience and Biotechnology, Faculty of
Science and Engineering, Ritumeikan University, 5South Product Ltd., 6JST-CREST

Chlorophylls c (Chls c) are characterized by a fully conjugated porphyrin !-system aswell as a unique acrylate acid at the 17-position (17-CH=CH-COOH). Therefore it isexpected that protonation/de-protonation at the acrylate acid of Chls c affect their
optical properties. In this study, absorption and fluorescence spectra of both Chl c1 andChl c2 in 80% ethanol/water were compared under various pH values. The relative
absorbances and fluorescence quantum yields of both Chl c1 and Chl c2 exhibited clear
pH dependencies. Their acid dissociation counts were determined. The opticalproperties of methyl ester-substituted Chl c1 (17-CH=CH-COOCH3) were found not toshow the pH dependencies, indicating the pH dependencies originated fromprotonation/de-protonation at the acrylate acid.

̶ 66 ̶

PS13. Applications of Peptide Gemini Surfactants as Novel Solubilization
Surfactants for Photosystems I and II of Cyanobacteria
S. Koeda,1 T. Mizuno,1* T. Noji,1 T. Dewa,1 T. Tanaka,1 M. Nango2
1

Graduate Shcool of Engineering, Nagoya Institute of Technology,
2
OCARINA, Osaka City Univercity,
1
Gokiso-cho, showa-ku, Nagoya, Aichi 466-8555, Japan1
Phone/Fax: +81-52-735-5237; E-mail:cjk15042@stn.nitech.ac.jp
Recently, we have studied novel gemini-type peptide surfactants (PG-surfactants), andthe oligo-Asp series of PG-surfactants, D3C12 and D4C12, are found to exhibit higher
micelle-formation properties and tend to form bilayer morphologies. On the other hand,
photosystems I and II (PSI and PSII) are two of the representative photosynthetic
membrane proteins and these play key roles in absorbing photons from sunlight andproducing electrons or holes via charge separation at the reaction center. In thethylakoid membrane, PSI and PSII take homotrimer and homodimer as a stablesupramolecular complex, respectively. In this study, we designed new PG-surfactants,
DKDKC12K and DKDKC12D, that could be utilize as a novel solubilization surfactant
for membrane proteins, especially PSI trimer and PSII dimer.
From the comparison of absorption spectra of PSI trimer and PSII dimer solubilizedwith 0.1 wt% b-DDM and 0.1 wt% DKDKC12K or DKDKC12D, we confirmed thatthese PG-surfactants were able to solubilize PSI trimer and PSII dimer without
denaturation. Using the dynamic light scattering measurements, these PG-surfactants
can solubilize PSI trimer and PSII dimer without furterh aggregations. With respect tothe activities of light-induced electron transfer initiated from reaction center, PSI trimer
and PSII dimer solubilized with these PG-surfactants retained the original electrontransfer activities.

̶ 67 ̶

PS14. How iodide ions inhibit the oxygen evolution of photosystem II?
Keisuke Kawakami1, Daisuke Hgiwara2, Yasufumi Umena1, Jian-Ren Shen3,
Nobuo Kamiya1,2
1

The OCU Advanced Research Institute for Natural Science and Technology, Osaka
City university, 2Graduate School of Science, Osaka City University, 3Graduate Schoolof Natural Science and Technology, Okayama University.
Oxygen-evolving photosystem II (PSII) is the site of light-induced water-splitting andprovides us with molecular oxygen indispensible for life on the earth. Chloride ion (Cl-)
is an essential cofactor for oxygen evolution of PSII, and is closely associated with the
Mn4CaO5-cluster. Substitution of Cl- with iodide ion (I-) completely inhibited oxygen
evolution of PSII, whereas substitution of Cl- with Bromide ions (Br-) did not inhibit
oxygen evolution. In this symposium, we will discuss the conformational changes
around the Mn4CaO5-cluster due to the substitution of Cl- with I-.

PS15. Syntheses of sulfur bridged Mo complexes with dithiophosphate ligand andthe stability controlled by functional ligand!KAWAMOTO, Keisuke; ICHIMURA, Akio; KINOSHITA, Isamu
Osaka City Univ., OCARINA
The syntheses and the X-ray structure of incomplete cubane-type complex[Mo3S4(dtp)3- (µ2-dtp)(pyrazine)] have been reported. In the cyclicvoltammetry, themixture of the complex and CF3COOH shows catalytic current after overnight. The
catalytic current increased with the concentration of CF3COOH. The 1H NMR spectraof the complex at various temperatures indicate the structure in solution as follows: 1) apyrazine coordinated species is in equilibrium with a pyrazine uncoordinated one insolution. 2) the equilibrium is strongly shifted to the dissociated species at room
temperature. 3) the all pyrazine hydrogen atoms can distinguish at -30oC and lower
because of a restricted rotation about the Mo-N (pyrazine) bond.

̶ 68 ̶

PS16. Syntheses and Characterization of Novel Sulfido PtM2 (M = Rh, Ir) Type
Trinuclear Complexes with Chelated N-Heterocyclic Carbene Ligands
Yuri Maeda,* Hideki Hashimoto, Isamu Kinoshita, and Takanori Nishioka
Division of Molecular Materials Science, Graduate School of Science, Osaka City
University The OCU Advanced Research Institute of Natural Science and Technology(OCARINA)
A bottom up method to construct sulfido bridged multinuclear complexes with Nheterocyclic carbene ligands using the hydrosulfido platinum complexes, [Pt(bisNHCCn-R)(SH)2], was performed. From X-ray structural analyses of the trinuclear
complexes, the M2Pt triangle cores are isosceles triangles with shorter M–M distances.
The cyclic voltammetry of the heterometallic trinuclear complexes showed two
reversible reduction peaks and only the second reduction potentials were affected by thelengths of the bridging alkyl chains of the bisNHC ligands. No significant differenceswere observed for the absorption maxima with the variation of N-substituents but small
differences were found with the different chain lengths.

PS17. Exciton-exciton annihilation in light harvesting complexes from a purple
bacterum
Yuya Nagaoka A,B, Daisuke Kosumi B,C, Ritsuko Fujii B,C , Mitsuru Sugisaki A,B,C, andHideki Hashimoto A,B,C
Osaka City Univ. A, CREST/JST B, OCARINA C
Both relaxation of a two-exciton state and exciton-exciton annihilation inbacteriochlorophylls of the light harvesting complexes from a photosynthetic purple
bacterium have been studied by femtosecond pump-probe spectroscopy. In this study,
we have targeted the B875 (bacteriochlorophyll) ring of the light harvesting complexes(LH1) from a photosynthetic purple bacterium, Rsp. rubrum G9. The lifetime of twoexciton state was determined to be a few ps, and exciton-exciton annihilation occurredin ~10 ps after excitation to the Qy band. A new method for analyzing the excitonexciton annihilation in LH1 thus proposed can be a clue to clarify the excitation energy
transfer between the light harvesting complexes.

̶ 69 ̶

PS18. Towards Catalytic Water Oxidation: Synthesis of a Cobalt(III)-Oxon Cuban
Cluster with protected-p-pyridylphosphonato ligand
Tomoyuki HASEGAWA, Keisuke KAWAMOTO, Isamu KINOSHITA
Osaka City Univ., OCARINA
Water oxidation is a very important process for artificial photosynthesis. We intend toconstruct a water oxidation system. A water oxidation catalyst is combined to anelectrode via a semiconductor photocatalyst, which acts as a photochemical reaction
center. The system will be able to directly incorporated into reducing site on anelectrode. We have focused on a Cobalt(III)-Oxo Cubane Cluster[Co4O4(OAc)4(Pyridine)] as a water oxidation catalyst, because iso-structuralcomplexes of [Co4O4(OAc)4(Pyridine)] have been synthesized by using p-substituted
pyridine derivatives. Herein, we report the synthesis of [Co4O4(OAc)4(p-pyridyl-Oprotected-phosphonato-kN)], which is possibly condensed on a semiconductor
photocatalyst.

PS19. Computational analysis of the electron-transfer inhibitors in Photosystem II
Ayako Tanaka1,Satoshi Suzuri1,Asada Toshio2, Keisuke Kawakami3, Yasufumi
Umena3,5, Jian-Ren Shen4, Miyahara Ikuko1,3, Nobuo Kamiya3,11Graduate School of Science, Osaka City University; 2Depart of Chemistry, Osaka
Prefecture University; 3The OCU Advanced Research Institute for Natural Science andTechnology (OCARINA), Osaka City University; 4Division of Bioscience, Graduate
School of Natural Science and Technology/Faculty of Science, Okayama University;
5
Japan Science and Technology Agency (JST), Precursory Research for Embryonic
Science and Technology
Photosystem II (PSII) is a large protein complex catalyzing water oxidation andplastoquinone reduction. PSII monomer has two plastoquinones, QA and QB. After light
excitation and charge separation, an electron is transferred to QA, then QB. The key
factor in this electron transfer is redox potential. Herbisides bind QB site and inhibit theelectron transfer from QA. These herbicides have been classified into several types;
phenolic-, triazine-, uracil-, and urea-types. The representatives of the four types are
bromoxynil, terbutryn, bromacil, and DCMU, respectively. Using a quantum
mechanical and molecular mechanical (QM/MM) method, we analyzed the redox
potentials of QB and herbicides. Based on these results, we will discuss the structurefunction relationships of the herbicides in PSII.

̶ 70 ̶

PS20. Regulation of the receptor ability of Zn-porphyrin by the formation of Fe
complexes*Yoshikazu Ninomiya, Masatoshi Kozaki, Shuichi Suzuki, Keiji Okada
Molecular materials Science, Graduate School of Science, Osaka City University
We prepared Zn-porphyrin-inserted phenylene-ethynylene oligomers (1). Bipyridine
chromophore was attached at one end of oligomer 1, and the other end of the oligomers
was diverged and attached to two other bipyridine rings through flexible alkyl chains.
Addition of Fe(II) to 1 cleanly produced a Fe(bpy)3-type complex 2. In the complex 2,
the Zn-porphyrin moiety was covered by flexible alkyl chains. Because of thisgeometrical change, the axial coordination on the Zn-porphyrin is thought to be
suppressed. The degree of suppression was shown to be dependent on both alkyl chain
length and bulkiness of axial ligands.

PS21. Structural study on the Mn atoms in the oxygen-evolving complex of
Photosystem II by X-ray absorption techniques    
!UMENA, Yasufumia,b, KAWAKAMI, Keisukea, Tanka, Ayakob, SHEN, Jian-Renc,
KAMIYA, Nobuoa, d.
a
The OCU Advanced Research Institute for Natural Science and Technology(OCARINA), Osaka City Univ., bJST-PRESTO, cGraduate School of Natural Scienceand Technology/Faculty of Science, Okayama Univ., dGraduate School of Science,
Osaka City Univ.
Molecular oxygen on Earth is generated from photosynthesis by cyanobacteria, algae
and plants, where water molecules are split by Photosystem II (PSII). PSII performs aseries of light-induced electron transfer reactions to generate molecular oxygen. The
catalytic center for water-splitting in PSII is composed of four Mn atoms and one Ca
atom organized in a Mn4CaO5-cluster, which cycles through several different redox
states to accomplish the catalytic process. In this study, we analyzed the electronic stateof each Mn atom by X-ray at the wavelength on the Mn K-absorption edge. We will
discuss each Mn valence of the cluster based on crystallogaraphic analysis.

̶ 71 ̶

PS22. The pH titration experiment in the crystals of ADPRase-ADPR binary
complexes!

Yurie Tomita1, Yoshihiko Furuike2, Ikuko Miyahara2,3, and Nobuo Kamiya3,21Faculty of Science, and 2Graduate School of Science, Osaka City University
3
The OCU Advanced Research Institute for Natural Science and Technology(OCARINA), Osaka City University

ADPRase is an enzyme, which hydrolyzes ADP-ribose (ADPR) into ribose-5’phosphate and AMP in the presence of divalent metal ions. In order to identify thegeneral acid - base catalysts in the ADPR hydrolysis reaction, we investigated the pH
effect on the geometry of ADPR diphosphate in seven crystals of ADPRase-ADPR
binary complexes with different pHs. The "-phosphate changed its P-O bond lengths
with a pKa value of 4.2, while the #-phosphate didn’t. This indicates the difference ofenvironments in which "- and #-phosphate are placed. The protonation state of the #phosphate is likely controlled by the well-designed hydrogen bonding network
including the acid catalyst during the ADPR hydrolysis reaction.

PS23. Design of Polyoxometalates Aimed to Artificial Photosynthesis
Hitoshi Yoneda1,3, Keisuke Kawamoto 1,3, Toshio Asada 4, Isamu Kinoshita1,2,3, andHideki Hashimoto1,2,3
1

The OCU Advanced Research Institute for Natural Science and Technology(OCARINA), Osaka City University, Osaka, Japan, 2CREST/JST, 3Graduate School of
Science, Osaka City University, Osaka, Japan, 4Graduate School of Science, Osaka
Prefecture University, Osaka, Japan.
Polyoxometalates (POM) can manage the oxidation-reduction reaction of manyelectron systems. They are expected as the potential candidates for the application of
constructing artificial photosynthesis system. On the other hand, it has already been
known that pyridine has the ability to catalyze the reduction of carbon dioxide intomethanol [1]. Therefore, we investigated the possibility to combine these two systems
in silico. In particular, we focus our attention to the process of reduction of carbon
dioxides by pyridines as well as the possibility of incorporating pyridines into the POM
system. Quantum chemical calculations have been performed using Gaussian09.
[1] E.B. Cole, P.S. Lakkaraju, D.M. Rampulla, A.J. Morris, E. Abelev, and A.B.
Bocarsly. J. Am. Chem. Soc. 2010, 132, 11539-11551.

̶ 72 ̶

PS24. Synthesis and Magnetic Properties of Iron and Cobalt Complexes
Containing a !-Radical Ligand with Photo-Excited High-Spin State
Koichi Katayama
Graduate School of Science, Osaka City University
We synthesized a new ligand, L1, which is p-radical with a bipyridyl group. The pradical ligand L1 has a doublet state in the ground state. The photo-excited quartet (S =3/2) state of L1 was detected by time-resolved ESR, which is constructed by the
intramolecular ferromagnetic spin alignment between the doublet spin in the oxoverdazyl radical and pp* excited triplet state of the phenylanthracene moiety. Fe(II) andCo complexes were synthesized using the !-radical ligand. The Fe(II) complex showeda spin crossover transition and a LIESST phenomenon. The Co complex showed avalence tautomerism in solution.

PS25. Relationship of charge of heads group of lipid and photochemical activity ofphotosystem II in reconstituted lipid bilayer
Tomoyasu Noji1, Masaharu Kondo1, Keisuke Kawakami2, Jian-ren Shen3, Mamoru
Nango2,4, Takehisa Dewa1,51Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showaku, Nagoya 466-8555,Japan, 2Department of Chemistry, Graduate School of Science,
Osaka City University, 3-3-138 Sugimoto, Sumiyoshi, Osaka 558-8585, Japan,
3
Division of Bioscience, Graduate School of Natural Science and Technology/Facultyof Science, Okayama University, Okayama 700-8530, Japan, 4CREST/JST, Japan,
5
PRESTO/JST, Japan

PSII can be a material for the construction of artificial photosynthetic systems that canobtain electrons from water almost infinite. Recently, immobilization of PSII to gold
nano-particles or silica mesoporous materials was reported without denaturation. Thus,
construction of artificial “Z-scheme” was expected by inorganic nano-structures.
Therefore, reconstitution of PSI and PSII into lipid bilayers for immobilization to
inorganic nano-structures would be potential approach. It is expected that control ofimmobilization of lipid bilayers to surface of nano-structures by control of charge ofheads group of lipid. Therefore, oxygen evolution activities and durability of PSII inreconstituted various lipid bilayers were characterized.

̶ 73 ̶

PS26. Construction of Carotenoid Molecularly-Oriented Film:
A Model System of Photosynthetic Antenna
Shouhei Kita
Osaka City University
Carotenoid is a pigment molecule that absorbs light energy and transfers it to nearby
chlorophylls in photosynthetic antenna. The efficiency of the energy transfer depends
mainly on the intermolecular distance and the molecular orientation. The aim of thisresearch is to construct a carotenoid film where the intermolecular distance andmolecular orientation of carotenoids are controlled to correlate the efficiency of theenergy transfer as a function of these parameters. In this work, we prepared a barium
stearate Langmuir-Blodgett film containing all-trans-b-carotene with a lipid to substrate
ratio of 5 / 1 (v/v), and determined the molecular orientation of b-carotene by polarized
optical absorption and reflection spectroscopies. We also evaluated the surface of LB
films by the atomic force microscope.

PS27. Photoinduced Electron Transfer of Platinum Bipyridine Diacetylides Linked
by Triphenylamine and Naphthalenediimide and its application to photoelectric
conversion system
Shuichi Suzuki,*a,b Yuma Matsumoto,a Mai Tsubamoto,a Masatoshi Kozaki,a Kenshi
Kimoto,c Munetaka Iwamura,c Koichi Nozaki,c Naoki Senju,a Chiasa Uragami,a Hideki
Hashimoto,a,b,d and Keiji Okadaa,baGraduate School of Science, Osaka City University, b The Osaka City University
Advanced Research Institute for Natural Science and Technology (OCARINA), c
Graduate School of Science and Engineering, University of Toyama, d JST/CREST
The recently reported efficient charge-separated system based on bipyridine-diacetylide
platinum complexes was applied to a photoelectric conversion system herein, based on
MTA-Pt-NDISAc (MTA: dimethoxytriphenylamine, Pt: platinum complex, NDISAc:
thioacetate derivative linked to naphthalenediimide). The charge-separated (CS) state of
MTA-Pt-NDISAc was effectively generated by photo-induced electron transfer intoluene and THF. The lifetimes of the CS states were determined to be 730 ns in toluene
and 61 ns (70%) and 170 ns (30%) as a double exponential decay in THF. The
acetylthio group of triad MTA-Pt-NDISAc was exploited in the preparation of a selfassembled monolayer (SAM) on a gold surface. A photocurrent was detected upon
irradiation of an electrochemical cell comprising Au/MTA-Pt-NDISAc /Na ascorbate/Pt,
which was ascribed to the platinum complex based on the action spectrum.
̶ 74 ̶

PS28. Syntheses and Properties of Nickel and Zinc Complexes
with a Tripodal Ligand, 1-(pyridine-2-yl)-2,2-bis(pyridine-2-ylthio)ethanone
Yu Masuda
Osaka City University
Tripodal ligand 1-(pyridine-2-yl)-2,2-bis(pyridine-2-ylthio)ethanone ( = ppte) reacts
with several first transition metal ions to form metal complexes with a metal-carbon
bond. The Ni(II) complex [Ni(m-Cl)(ppte)]2 (1) has a dinuclear structure bridged by two
chloride ligands. In dichlorometane, the cyclic voltammogram of 1 exhibited stepwise
reversible redox waves for the dinuclear nickel species. The oxidation reaction of 1 by
one equivalent of (p-tol)3NPF6 in dichloromethane generated a rare Ni(II,III) mixedvalence complex, [NiII,III(m-Cl)(ppte)]2, and by two equivalent of (p-tol)3NPF6
generated the Ni(III) complex [NiIII(m-Cl)(ppte)]2. On the other hand, the Zn(II)complex [ZnCl(ppte)]2 has a dimer structure containing C=O coordination to anotherzinc to each other, and showed keto-enolate intermediate conformation.

PS29. A Trial for Developing the Hybrid Artificial Photosynthesis
Yui Takemoto, Keisuke Kawakami, Isamu Kinoshita
Osaka City University; Graduate School of Science, OCARINA
Sunlight is the clean, sustainable only energy replaced with a fossil fuel. Artificial
photosynthesis attracts much attention as a way to produce solar fuels efficiently fromsunlight. Recently, Tiede and co-workers reported a new strategy for solar fuelproduction using hybrid of Photosystem I (PSI) and cobaloxime. We have tried tofabricate the hybrid photosynthesis system using Thermosynechococcus vulcanusderived PSI and cobaloxime. Additionally, by using DCIP (= 2,6-dichloroindophenol)
and PMS (= phenazine methosulfate) as a mediator instead of Cytochrome c6, we try to
improve the system more artificially for hydrogen production.

̶ 75 ̶̶ 76 ̶