Noboru Kitamura
Research Area：Microchemistry, Photochemistry, Microspectroscopy
Research Project: A Study on Laser Microchemistry
Academic Carrier
1976: Bachelor Degree, Tokyo Metropolitan University
1978: Master Degree, Tokyo Institute of Technology
1980: Doctor of Science, Tokyo Institute of Technology
Job Carrier
May, 1978: Technical Assistant, Tokyo Institute of Technology
June, 1989: Research Associate, Tokyo Institute of Technology
October, 1988: Technical Manager, ERATO Microphotoconversion Project, JST
April, 1993: Professor, Department of Chemistry, Faculty of Science, Hokkaido University
April, 1995: Professor, Division of Chemistry, Graduate School of Science, Hokkaido University
April, 2006: Professor, Department of Chemistry, Graduate School of Science, Hokkaido University
April, 2019: Visiting Fellow, Toyota Physical and Chemical Research InstituteResearch Background
1. Studies on Microchemistry
1.1. Laser Trapping Microspectroscopy of Single Microparticles in
Solution:

We have developed laser trapping – microspectroscopy(absorption/fluorescence/Raman)

techniquesofvarioussinglemicroparticles in solution. As shown in Fig. 1, one can manipulate single
microparticles (polymer beads, droplets, biological cells, and so forth) bya laser beam under an optical microscope. On the basis of this particulartechnique, we have demonstrated

1) in situ

observation of the ion

Fig. 1. Laser manipulation of asingle microparticle in water.

diffusion processes in single ion-exchange resin microparticles, 2) the mass/electron transfer processes acrosssingle microdroplet/water interfaces, 3) the photochemical cyanation reaction of an aromatic hydrocarbon
across a single droplet/water interface.
．
1.2. Simultaneous Extraction Detection of an Analyte Based on a Laser-Induced Microparticle
Formation Technique:Some of an aqueous oil solution shows temperature-dependent phase separation.

As an example, an aqueous butanol (BuOH) solution undergoes phase separation at around room temperature.
On the other hand, water (H2O) absorbs 1064 nm light through the overtone bands of the OH-vibration modeof water. Based on such phenomena, one can produce a single BuOH microdroplet by focused 1064 nm laser
irradiation to an aqueous BuOH solution: Fig. 2. Similarly, focused
continuous-wave 1064 nm laser irradiation to an aqueous poly(Nisopropyl acrylamide) (PNIPAM)/alcohol solution under an opticalFig.
2.
Laser-induced
singlemicroscope can produce single PNIPAM/alcohol microparticle and microdroplet formation in an aqueous
butanol solution (7.1 wt%).
the produced microparticle is trapped simultaneously by the incident

laser beam. In the presence of a fluorescent dye, rhodamine B (RhB), RhB is extracted to the microparticle
produced by laser irradiation. Our preliminary study has demonstrated that RhB in an aqueous
PNIPAM/butanol (BuOH) solution as low as 10–15 mol/L is extracted to the PNIPAM/BuOH microparticle
as demonstrated by in situ fuluorescence microspectroscopy of the microparticle. In practice, we haveconfirmed laser-induced extraction of RhB to the PNIPAM/BuOH microparticle at a single molecule level.
1.3.
1.3. Laser Trapping of Single aerosol roplets in Air:We havesucceeded in laser trapping of single aerosol water droplets levitatedin air. Furthermore, we have demonstrated that aerosol water
droplets in air do not freeze down to –60 ºC since the water droplet
levitated in air without physical contact other than air is not likely
to form a freezing nucleus: see Fig. 3. Similar to the aerosol water
droplets, single aerosol dimethyl sulfoxide (DMSO) or tert-BuOH
droplets with the bulk freezing temperature (fp) being +18.5 and+25.7 ºC, respectively, does not freeze in air down to –60 andca.

Fig. 3. Laser trapping of a single
aerosol water droplets at several
temperatures.

0 ºC, respectively. Furthermore, we have demonstrated that the solution viscosity of aerosol DMSO, water,or ethanol droplets increased with a decrease in the aerosol droplet diameter.
1.4 Development of Pulsed Laser Shock Wave Technique for Mechanochemical Phenomena: We
reported triboluminescence of N-alkylcarbazole crystals. Triboluminescence of crystals is in general induced

triboluminescence.

For

quantitative

discussion

ontriboluminescence, we proposed a pulsed laser shock wave
(PLSW) method. In the PLSW method, a shock wave generated

Intensityof

TL Intensity

therefore, such experiments cannot afford quantitative information

Shock Waveby manual grinding of the crystals by a glass rods or spatula and,

ｭby irradiation of a pulsed laser beam to a solid substrate isemployed as mechanical force for triboluminescence. In practice,

Laser Power / J

we have succeeded in determining the threshold laser power toFig. 4 Triboluminescence of Nisopropylcarbazole crystals by a pulsed
laser shock wave technique.

induce triboluminescence of N-isopropyl carbazole crystals by the
PLSW method.
2. Photochemistry
Compounds:of

Organic

andTransition

Metal

We reported the spectroscopic and photophysicalproperties of various organic (triarylboranes) and transition metal
complexes (Ru(II), Pt(II), Re(I), Mo(II), W(II), etc). As an example,
we have found that octahedral hexanuclear metal cluster complexes
whose general structure is shown in Fig. 5 show intense and longlived phosphorescence both in solution and solid phases at room

Fig. 5. Structure of an octahedral
hexanuclear molybdenum(II) cluster.

temperature. In order to elucidate such unique emission propertiesof a hexanuclear metal complex, we recently conducted a3systematic study on the spectroscopic and photophysical propertiesof a series of hexanuclear Mo(II) clusters in the temperature (T)21range of 3 ~ 300 K. The study has demonstrated the emitting excitedtriplet state of an Mo(II) cluster splits in energy as large as ca. 1000
cm–1 and the splitting energies in the excited triplet state of Mo(II)complexes (E1n) are shown to be correlated linearly with the forth
power of the atomic number of the atom composed of theclusterFig. 6. Correlation between E1n

and [Z(X)]4 of a series
hexanuclear Mo(II) clusters.

of(Z(X)): E1n ∝ [Z(X)]4, Figure 6. This is the first demonstration for the Z4 power dependence of the zeromagnetic-field splitting in the excited triplet state.

Publication List

Selected original papers
1. Terminal Ligand (L) Effects on Zero-Magnetic-Field Splitting in the Excited Triplet States of[{Mo6Br8}L6]2– (L = Aromatic Carboxylates), S. Akagi, T. Horiguchi, S. Fujii, and N. Kitamura.
Inorg. Chem., 2019, 58, 703 – 714.
2. Emission Tuning of Heteroleptic Arylborane-Ruthenium(II) Complexes by Ancillary Ligands:
Observation of Strickler-Berg Relation, A. Nakagawa, A. Ito, E. Sakuda, S. Fujii, and N. Kitamura.
Inorg. Chem. 2018, 57, 9055 – 9066.
3. Zero-Magnetic-Field Splitting in the Excited Triplet States of Octahedral Hexanuclear
Molybdenum(II) Clusters: [{Mo6X8}Y6]2– (X, Y = Cl, Br, I), S. Akagi, S. Fujii, and N. Kitamura. J.
Phys. Chem. A, 2018, 122, 9014 – 9024.
4. A Study on the Redox, Spectroscopic, and Photophysical Characteristics of a Series of Octahedral
Hexamolybdenum(II) Clusters: [{Mo6X8}Y6]2– (X, Y = Cl, Br, I), S. Akagi, S. Fujii, and N. Kitamura.
Dalton Trans., 2018, 47, 1131 – 1139.
5. Laser-Induced Single Microdroplet Formation and Simultaneous Water-to-Single Microdroplet
Extraction/ Detection in Aqueous 1-Butanol Solutions, N. Kitamura, K. Konno, and S. Ishizaka. Bull.
Chem. Soc. Jpn., 2017, 90, 404 – 410.
6. Zero-Magnetic-Filed Splitting in the Excited Triplet States of Octahedral Hexanuclear Molybdenum(II)Clusters: [{Mo6X8}(n-C3F7COO)6]2– (X = Cl, Br, I), S. Akagi, E. Sakuda, A. Ito, and N. Kitamura. J.
Phys. Chem. A, 2017, 121, 7148 – 7156.
7. Excited Triplet States of [{Mo6Cl8}Cl6]2–, [{Re6S8}Cl6]4–, and [{W6Cl8}Cl6]2– Clusters, N. Kitamura,
Y. Kuwahara, Y. Ueda, Y. Ito, S. Ishizaka, Y. Sasaki, K. Tsuge, and S. Akagi. Bull. Chem. Soc. Jpn.,
2017, 90, 1174 – 1179.
8. Synthetic Tuning of Redox, Spectroscopic, and Photophysucal Properties of {Mo6I8}4+-Core Cluster
Complexes by Terminal Carboxylate Ligands, M. A. Mihailov, K. A. Brylev, P. A. Abramov, E. Sakuda,
S. Akagi, A. Ito, N. Kitamura, and M. N. Sokolov. Inorg. Chem., 2016, 55, 8437 – 8445.
9. Near-Infrared Laser-Induced Temperature Elevation in Optically-Trapped Aqueous Droplets in Air, S.
Ishizaka, J. Ma, T. Fujiwara, K. Yamauchi, and N. Kitamura. Anal. Sci., 2016, 32, 425 – 430.
10. Remarkably Intense Emission from Ruthenium(II) Complexes with Multiple Borane Centers, A.
Nakagawa, E. Sakuda, A. Ito, and N. Kitamura. Inorg. Chem., 2015, 54, 10287 – 10295.
11. Dual Emissions from Ruthenium(II) Complexes Having 4-Arylethynyl-1,10-phenanthroline at Low
Temperature, E. Sakuda, C. Matsumoto, Y. Ando, A. Ito, K. Mochida, A. Nakagawa, and N. Kitamura.
Inorg. Chem., 2015, 54, 3245 – 3252.
12. Reversible Control of the Equilibrium Size of a Single Aerosol Droplet by Change in Relative Humidity,
S. Ishizaka, K. Yamauchi, and N. Kitamura. Anal. Sci., 2014, 30, 1075 – 1079.
13. In Situ Quantification of Ammonium Sulfate in Single Aerosol Droplets by Means of Laser Trapping
and Raman Spectroscopy, S. Ishizaka, K. Yamauchi, and N. Kitamura. Anal. Sci., 2013, 29, 1223 –1226.
14. Mechanical Stimulation and Solid Seeding Trigger Single-Crystal-to-Single Crystal Molecular Domino
Transformation, H. Ito, M. Muromoto, S. Kurenuma, S. Ishizaka, N. Kitamura, H. Sato, and T. Seki.
Nature Commun., 2013, DOI10.1038/ncomms3009.
15. Photophysical and Photoredox Characteristics of a Novel Tricarbonyl Rhenium(I) Complex Having an
Arylborane Appended Aromatic Diimine Ligand, A. Ito, Y. Kang, S. Saito, E. Sakuda, and N. Kitamura.
Inorg. Chem., 2012, 51, 7722 – 7732.
16. In Situ Observations of Freezing Processes of Single Micrometer-Sized Aqueous Ammonium Sulfate
Droplet in Air, S. Ishizaka, T. Wada, and N. Kitamura. Chem. Phys. Lett., 2011, 506, 117 – 121.
17. Laser Trapping and Picosecond Time-Resolved Spectroscopy of Water Droplets in Air: Cavity-Enhanced
Spontaneous Emission of Ru(bpy)3Cl2, S. Ishizaka, Y. Suzuki, and N. Kitamura. Phys. Chem. Chem.
Phys., 2010, 12, 9852 – 9857.
18. Optical Trapping of Amino Acids in Aqueous Solutions, Y. Tsuboi, T. Shoji, and N. Kitamura. J. Phys.
Chem. C, 2010, 114, 5589 – 5593.
19. Laser-Induced Shock Wave Can Spark Triboluminescence of Amorphous Sugars, Y. Tsuboi, T. Seto, andN. Kitamura. J. Phys. Chem. A, 2008, 112, 6517 – 6521.

20. Reversible Mechanochromic Luminescence of [(C6H5Au)2(-1,4-diisocyanobenzene)], H. Ito, T. Saito,
N. Oshima, N. Kitamura, S. Ishizaka, Y. Hinatsu, M. Wakeshima, M. Kato, K. Tsuge, and M. Sawamura.
J. Am. Chem. Soc., 2008, 130, 10044 – 10045.
21. Synthesis and Spectroscopic Properties of Novel Platinum(II) Terpyridine Complexes Having
Arylborane Charge Transfer Unit, E. Sakuda, A. Funahashi, and N. Kitamura. Inorg. Chem., 2006, 45,
10670–10677.
22. Laser-Induced Liquid-to-Droplet Extraction of Chlorophenol: Photo-Thermal Phase Separation of
Aqueous Triethylamine Solutions, N. Kitamura, M. Yamada, S. Ishizaka, and K. Konno., Anal. Chem.,
2005, 77, 6055 – 6061.
23. Direct Observation of Molecular Recognition mediated by Triple Hydrogen Bonds at a Water/Oil
Interface: Time-Resolved Total Internal Reflection Fluorometry Study, S. Ishizaka, S. Kinoshita, N.
Nishijima, and N. Kitamura. Anal. Chem., 2003, 75, 6035 – 6042.
24. Laser-Driven Shock Wave-Induced Triboluminescence of Organic Crystals: Toward a Semi-Quantitative
Study, Y. Tsuboi, T. Seto, and N. Kitamura. J. Phys. Chem. B, 2003, 107, 7547 – 7550.
25. Characteristic Electrochemical Responses of Polymer Microchannel-Microelectrode Chips, K. Ueno,
H.-B. Kim, and N. Kitamura. Anal. Chem., 2002, 74, 2086 – 2091.
26. Photocyanation of Pyrene across an Oil/Water Interface in a Polymer Microchannel Chip, K. Ueno, F.
Kitagawa, and N. Kitamura. Lab. Chi., 2002, 231 – 234.
27. Water Structures in Ion-Exchange Resin Particles: Solvation Dynamics of Nile Blue A, S. Habuchi, H.B. Kim, and N. Kitamura. Anal. Chem., 2001, 73, 366 – 372.
28. Fabrication and Characteristic Responses of Integrated Microelectrodes in Polymer Microchannel Chip,
K. Ueno, F. Kitagawa, H.-B. Kim, T. Tokunaga, S. Matsuo, H. Misawa, and N. Kitamura. Chem. Lett.,
2000, 858 – 859.
29. Excitation Energy Transfer from Sulforhodamine 101 to Acid Blue 1 at a Liquid/Liquid Interface:
Experimental Approach to Estimate Interfacial Roughness, S. Ishizaka, S. Habuchi, H.-B. Kim, and N.
Kitamura. Anal. Chem., 1999, 71, 3382 – 3389.
30. Dynamic Fluorescence Spectroscopic Study on the Microstructures in Ion-Exchange Resin Particles, H.B. Kim, S. Habuchi, and N. Kitamura. Anal. Chem., 1999, 71, 842 – 848.
31. Optical Transformation and Fission of Single Giant Vesicles in Water by Radiation Pressure, N.
Kitamura, N. Sekiguchi, and H.-B. Kim. J. Am. Chem. Soc., 1998, 120, 1942 – 1943.
32. Direct Excitation Energy-Transfer as a Technique for in Situ Measurements of Ion-Exchange Processes
in Single Polymer Particles, H.-B. Kim, S. Habuchi, M. Hayashi, and N. Kitamura. Anal. Chem., 1998,
70, 105 – 110.
33. Effects of Sample Dimension and Dye Distribution Characteristics in Absorption Microspectroscopy,
H.-B. Kim, S. Yoshida, and N. Kitamura. Anal. Chem., 1998, 70, 51 – 57.
34. In Situ Measurements of Ion-Exchange Processes in Single Polymer Particles: Laser TrappingMicrospectroscopy and Confocal Fluorescence Microspectroscopy, H.-B. Kim, M. Hayashi, K. Nakatani,
N. Kitamura, K. Sasaki, J. Hotta, and H. Masuhara. Anal. Chem., 1996, 68, 409 – 414.
35. Picosecond Lasing Dynamics of a Single Dye-Doped Microparticle in Solution, K. Kamada, K. Sasaki,
H. Misawa, N. Kitamura, and H. Masuhara. Chem. Phys. Lett., 1993, 210, 89 – 93.
36. Multibeam Laser Manipulation and Fixation of Microparticles, H. Misawa, K. Sasaki, M. Koshioka, N.
Kitamura, and H. Masuhara. Appl. Phys. Lett., 1992, 60, 310 – 312.
37. Optical Trapping of a Metal Particle and a Water Droplet by a Scanning Laser Beam, K. Sasaki, M.
Koshioka, H. Misawa, N. Kitamura, and H. Masuhara. Appl. Phys. Lett., 1992, 60, 807 – 809.
38. Three-Dimensional Optical Trapping and Laser Ablation of a Single Polymer Latex Particle in Water, H.
Misawa, M. Koshioka, K. Sasaki, N. Kitamura, and H. Masuhara. J. Appl. Phys., 1991, 70, 3829–3836.
39. Laser Manipulation and Ablation of a Single Microcapsule in Water, H. Misawa, N. Kitamura, and H.
Masuhara. J. Am. Chem. Soc., 1991, 113, 7859 – 7863.
40. Pattern Formation and Flow Control of Fine Particles by Laser Scanning Micromanipulation, K. Sasaki,
M. Koshioka, H. Misawa, N. Kitamura, and H. Masuhara. Optics Lett., 1991, 16, 1463 – 1465.