Reserch Topics of Ishii Laboratory

In general, main group elements other than carbon and hydrogen are called heteroatoms. By adding a heteroatom as a functional group to a hydrocarbon composed of carbon and hydrogen, an organic compound having various properties like alcohol and amine is derived, and when a transition metal element is further added there, an interesting character often appears. We are studying the synthesis of such substances with unprecedented properties by combining hydrocarbons with not only heteroatoms but also transition metal elements and are investigating the synergistic effect of heteroatoms and transition metal elements that brings about such properties. The combination of carbon skeleton - heteroatom - transition metal element is infinite, and such research can have infinite possibilities.

We have developed novel tetradentate ligands with oxygen and sulfur as donor atoms and then synthesized a series of metal complexes with them. We have found that these complexes act as catalysts in the polymerization of olefins and produce the corresponding polyolefins with ultra-high activity and stereospecificity.
For example, the zirconium complex serves as a catalyst for the precise polymerization of 1-hexene, 4-methyl-1-pentene and propylene, showing broad substrate adaptability not found in conventional catalysts. Recently, we have succeeded in the production of optically active polymer and isospecific polymerization of polar monomers, which are expected as new polymer materials.


We have found that compounds containing a carbon skeleton called dibenzobarrelene and a heteroatom emit fluorescence with high efficiency. We have synthesized compounds having a Group 16 element, O, S, Se, and Te, in the E part, and compared systematically of their photophysical properties from viewpoints of both experiments and theoretical calculations to clarify the features of Group 16 elements. In this system, the color of fluorescence can be changed from blue to red ~ near infrared by tuning the electronic properties of substituents R1 and R2. In addition, we are studying on compounds of carbon, silicon (Group 14), and phosphorus (Group 15) to investigate how photophysical properties change depending on the type of heteroatoms. These luminescent compounds are expected to be applied in various applications as functional electronic materials and chemical sensors.