Site: Institute for Molecular Science (IMS)
Kazaki National Research Institutes
Myodaiji, Okazaki 444, Japan
Tel: (81) 564-55 7240; Fax: (81) 564-55 5245
Date Visited: 23 July 1997
WTEC: L. Jelinski (report author)
The Institute for Molecular Science (IMS) is one of three institutes under the umbrella of the Okazaki National Research Institutes. The other two are the National Institute for Basic Biology and the National Institute for Physiological Sciences. Together, they employ over two hundred professionals and about 180 technical and support staff. Each of the three Institutes is headed by a Director-General, who reports to the President. The Institutes are funded by the Ministry of Education, Science, Sports, and Culture (Monbusho).
Research at IMS is directed toward understanding the properties of molecules and molecular assemblies, and to the design and synthesis of new materials, especially those with novel properties. IMS is strongly oriented toward basic research. The faculty members have few teaching duties and can devote themselves full-time to research.
IMS has an unusual, almost Harvard-like method for ensuring that research remains fresh and of high quality: it imposes the rule that none of the assistant and associate professors can remain at IMS as full professors. Instead, they must go to another institution for promotion, as IMS always hires its full professors from outside. The faculty with whom I spoke, including junior professors, thought that this policy worked quite well.
Research at IMS that falls within the scope of this report is in the general category of synthesis of novel materials, some with inspiration from biology and some with biomolecules as the building blocks. Most of the work that involves nanoparticles involves some form of organometallic chemistry. The hallmarks of the research are two-fold: creativity, and the soundness by which the new materials are characterized and evaluated. Much of the research the WTEC team saw on this visit has been published in high quality journals such as Nature and the Journal of the American Chemical Society, attesting to the international reputation of IMS and the high quality of the research. Several of the faculty have good collaborations with other scientists in Japan. One has an ongoing and productive NSF-funded collaboration with the University of Rochester, and another introduced the visiting WTEC team members to a visiting researcher, on leave from Emory University, who was spending six months in his lab.
Japan seems to be in a leadership role in the production of metallofullerenes. IMS has a large-scale facility for producing fullerenes, and Prof. Kato has been successful in producing C82 that contains Sc, Y, and La inside the cage structure. Kato is now using the metal inside the fullerene as a way to "tune" the reactivity of the outside. For example, he has shown how La@C82 can be reacted with disilanes and diazo compounds to form adducts. A combination of ESR and theory is being used to explain the reactivity of the precursor and the products obtained. One could imagine how this ground-up assembly of nanomaterials could be polymerized to produce larger molecules with novel properties.
Another area of research involves the characterization of magnetic transport and optical properties in phthallocyanines (Pc). Of special interest is PtPc(AsF6)0.5, whose transport properties are being studied under high pressure.
Prof. Shionoya, a very young full Professor who recently came to IMS from Hiroshima University, is using novel combinations of DNA, metal ligands, DNA templating, and proteins to produce molecular wires, molecular hoops through which DNA could be threaded, and double-stranded peptides whose helix pitch could be controlled by an entrained copper that could be induced to go from Cu(I)tetrahedral to Cu(II)square planar , perhaps by electrons delivered by an STM tip. Figure 7.6 (p. x in text) summarizes Prof. Shionoya's vision of how bioinspiration could be used to produce nanodevices.
In a very creative and careful series of single point mutations, Prof. Watanabe has uncovered evidence for, and verified the existence of a "push-pull" mechanism for cytochrome C peroxidase. This was done by drawing an analogy between peroxidase and cytochrome P-450, and using insights gleaned from similarities in the active site.
Finally, Prof. Fujita's work involves the approach of using self-assembly by transition metals to form organized large structures. He has been able to make various nanocages, which have potential applications for controlled drug release. He has also used three-dimensional organometallic cage compounds to achieve a "ship-in-a-bottle" synthesis of organic molecules and is currently producing nanostructured molecules with larger cavities than have ever been made before.