Create Molecules! Fascinate with Molecules!!

The world of molecules is full of beautiful and attractive structures, as represented by soccer ball-shaped fullerenes and double-helical DNA. On the other hand, there are many cases in which such beautiful molecules exhibit unexpected and surprising functions, and I believe the phrase "function in beauty” in the field of chemistry. Our goal is to design and synthesize such "attractive" molecules by ourselves. Our current research focuses on pi-conjugated molecules which exhibit functions based on their molecular structure and electronic properties. We are working on the creation of pi-conjugated molecules with unexplored structural motifs in order to elicit their unique functions.

Recent Research

I would like to briefly introduce some of molecules synthesized in my group recently .

Even in modern organic chemistry, it is not easy to bend oligophenyl compounds. In particular, bending them in the opposite direction like an S-shape is a difficult and challenging task, but we have achieved it with a unique synthetic strategy based on the connection of spirobifluorenes (see figure below) (J. Am. Chem. Soc. 2019, 141, 18238.) Two S-shaped para-oligophenyl chains mutually support each other. The key to achievement to synthesize such structure is that the two S-shaped para-oligophenyl chains support each other to maintain the S-shaped structure.

In addition, the cyclic linkage of chiral spirobifluorenes results in a structure that represents the unit of a woven pattern composed of para-quaterphenyl (see figure below). Although there have been no reports of such para-oligophenyl-constructed woven pattern motif molecules, we were able to synthesize them by cyclically linking chiral spirobifluorenes (Chem. Sci. 2020, 11, 9604. ).We also found that these motif molecules exhibit an unprecedented type of spiro-conjugation. More specifically, it is revealed based on DFT calculation that the split derived from spiro-conjugation is clearly affected by the number of the quaterphenyl unit chromophore.

Conducting Polymers

We are also developing new self-doped conductive polymers containing phosphonic acid in collaboration with companies. By using phosphonic acid, we aim to develop self-doped conductive polymers with properties different from those of sulfonic acid. An account paper summarizing our results is given below.

Development of Self-doped Conducting Polyaniline Bearing Phosphonic Acid Moiety

Toru Amaya, Toshikazu Hirao

Kobunshi Ronbunshu 74(6), 473-481 (2017).

https://doi.org/10.1295/koron.2017-0046