Molecular Design Laboratory

http://www.sci.osaka-cu.ac.jp/chem/SEKKEI/index_e.htm
Current Research and Principal Research Interests
Selected Publications
1. Current Research and Principal Research Interests
The interests of my research stand on "Coordination chemistry of transition metals". The actual
projects focus on "Investigation of the novel properties of the first transition metal complexes
toward functional materials using pyridine and sulfur as the composite units of the ligand."
Cluster Complexes. The aggregation of Complex units provides novel relationship between
structure, property and reactivity. The use of suitable building unit to construct the aggregate
enables us to explore novel featuring of M•••M interactions. One of the useful ligand for thispurpose is 2-pyridinethiolate. This ligand can coordinate to metal ion through monodentate,chelate, bridging, or multidentate fashion. The resulting multi-nuclear complexes possess
reasonable short Metal-Metal interaction suitable to produce novel property.

Figure 1. Structure of [Cu(4m-pyt)]6

Figure 2. Luminescent thermochromism of[Cu(4m-pyt)]6

The resulting complex, [Cu(6m-pyt)]6 (6m-pyt: 6-methyl-2-pyridinethiolato), exhibits
luminescent thermo-chromism that emit red light at ambient temperature from cluster centeredexited state and emit blue light at low temperature from ligand π* state. Pyridinethiol is also agood candidate to construct novel M-M state like Pt(III)-Co(II), and Pd(III)-Pd(III) states which
are hardly accessed under usual condition.

Novel functional ligands for elucidating valuable properties.The combination of pyridines andsulfurs in a ligand produces the special circumstances for first transition metals with particular
structure-property relationship. The strong interaction of p orbital of S atoms with pπ orbital ofpyridines affords electronic diversity to the ligand. The resulting complexes of first transition
metals would present catalytic activities alternative to the noble metal catalyst. Under thisprinciple, we have prepared the first example of transition metal complexes with macrocyclic
pyridines, thiacalix[n]pyridines, as a ligand. Especially, thiacalix[3]pyridine ( Py3S3 ) stabilizes
Cu(I) in certain extent, and the resulting complex has remarkable affinity to olefins and CO
molecules. We have now examined the catalytic activity of this complex. The complex alsopresent interesting photochemical behavior with relatively strong luminescent. The
unprecedented coordination of the ligand to a particular metal ion presents the novel feature forthe complexes. No previous research predicts the presence of the stable copper(II) complex with
Cu(II)-C(sp3) bond. We have designed and made an C3 symmetrical ligand of tris(pyridyl2-thio)methane that can coordinate via tetradentate fashion with liberation of the proton at thecentral carbon atom. The analogous ligand of bis(pyridylthio)metrane was found during thecourse of our previous research. Using tris(pyridyl-2-thio)methane, we have synthesized the firstexample of Cu(II)-C(sp3) bond. Contrary to the Py3S3, tris(pyridyl-2-thio)methane stabilizes thedivalent and trivalent oxidation state of copper complex. It is possible to elucidate the rational
reason for these properties as the significant mixing of sulfur p orbital with pyridine pπ orbital.
Now we are examining to arrange these system suitable for further application for catalyst,
photophysical devices, and others.

Figure 3. Reaction of tris(pyridyl-2-thio)methane with Cu(I)2. Selected Publications
1. "A complete series of copper(II) halide complexes (X = F, Cl, Br, I) with a novel CuII-C(sp3)bond " R. Miyamoto, R. Santo, T. Matsushita, T. Nishioka, A. Ichimura, Y. Teki and I.
Kinoshita, Dalton Trans. , 2005, 3179-3186.
2. "A two-dimensional clathrate hydrate sandwiched by planar arrays of a copper complex." R.
Miyamoto, R. T. Hamazawa, M. Hirotsu, T. Nishioka, I. Kinoshita, L. J. Wright,Chem.
Commun., 2005, 4047-4049.
3. "Selective oxygenation of amphiphilic thiacalix[3]pyridine Rh(I) dienecomplexes in bothwater and organic solvents.." T. Nishioka, Y. Onishi, K. Nakajo, J. Guo-Xin, R. Tanaka, I.
Kinoshita, J. Chem. Soc., Dalton Trans., 2005, 2130-2137.
4. "Catalytically Active Catalytically Active μ-oxodiiron(IV) Oxidants from Iron(III) andDioxygen." A. Ghosh, F. Tiago de Oliveira, T. Yano, T. Nishioka, E. S. Beach, I. Kinoshita, E.
Mu¨nck, A. D.Ryabov, C. P. Horwitz, and T. J. Collins, J. Am Chem. Soc., 2005, 127,2505-2513.

5. "Luminescence processes of hexanuclear methylpyridinethiolato-copper(I) crystals." Xie, H.
Y.; Tougezaka, M; Oishi, S; Kinoshita, I; Kanemoto, K; Akai, I; Karasawa, T., J. Luminescence,
2004, 108, 91-95.
6. "Activation of C-Cl and C-H bonds by ligated S-2(2-) ions: Conversion of organic chlorides
into organosulfur compounds in cis-[(IrCp*)2(μ-CH2)2(μ-S2R)](+)." T. S. Lobana, K. Isobe, H.
Kitayama, T. Nishioka, I. Kinoshita, Angew. Chem. Int.-ed., 43, 213-215 (2004).
7. "Pyridine-2-sulfonates as Versatile Ligands for the Synthesis of Novel Coordinative andHydrogen-Bonded Supramolecules." T. S. Lobana, I. Kinoshita, K. Kimura, T. Nishioka, D.
Shiomi, K. Isobe, Eur. J. Inorg. Chem., 2004, 356-367.
8. "Design and Synthesis of Copper Complexes of Novel Ligands based on the Pyridinethiol
Group", I. Kinoshita, L. J. Wright, S. Kubo, K. Kimura, A. Akata, T. Yano, R. Miyamoto, T.
Nishioka, K. Isobe, J. Chem. SOC., Dalton Trans., 2003, Special issue for Dalton Discussion 5.
9. "Laser Photolysis Studies on CuI Complexes of Thia-calix[3]pyridine. Phosphorescence fromthe Intramolecular Charge-Transfer Excited State" I. Kinoshita, A. Hamazawa, T. Nishioka, H.
Adachi, H. Suzuki, Y. Miyazaki, A. Tsuboyoma, S. Okada, M. Hoshino, Chem. Phys. Lett.,
2003, 371, 451-457.
10. "Thia-calix[n]pyridines, Synthesis and Coordination to Cu(I,II) ions with both N and S
Donor Atoms" R. Tanaka, T. Yano, T. Nishioka K. Nakajo, B. K. Breedlove; K. Kimura, I.
Kinoshita, K. Isobe, Chem. Commun., 2002, 1686-1687.