Prof. Yoshiyuki Kageyama

Hokkaido University

Abstract:

The construction of life-like molecular-based robots is currently an attractive research target in supramolecular chemistry. For this purpose, “autonomy in chemical system” is a key concept. Similar to engines, which are self-sustaining energy converters that have replaced the work of humans and animals, molecular-based engines are expected to operate autonomously with an energy supply. However, it has not been established how to assemble molecular-based engines with practical functions. In general, a molecular system tends to be in equilibrium or a steady state, where we cannot observe any macroscopic changes. On the other hand, our group has reported a novel type of light-driven self-continuous motion of azobenzene crystals. In the crystals, the chemical component, specifically the isomer ratio, oscillated due to alteration in photoisomerization efficiencies triggered by isomerization-induced crystalline phase transition. [1] By breaking Purcell’s scallop theorem, the tiny crystal exhibited self-propulsion with the powerful stroke in water, the direction of which was characterized by its flipping shape.[2] Furthermore, the speaker will address a recent challenge: describing the phenomenon in terms of reaction kinetics and translating it into a memory and processing device.[3] Additionally, the speaker will explore the possibility of generalizing the concept in which chemical reactions and the morphological changes behave synergistically to achieve far-from-equilibrium dynamics at micron-scale system level,[4] with introducing our study of vesicular self-reproduction[5] and the function of molecular motors.

[1] T. Ikegami, Y. Kageyama, et al. Angew. Chem. Int. Ed. 55, 8239 (2016); Y. Kageyama et al. Chem. Eur. J. 26, 10759 (2020).

[2] K. Obara, Y. Kageyama, et al. Small 18, 2105302 (2022).

[3] Y. Kageyama et al. arXiv 2301.0987 (2023).

[4] Y. Kageyama ChemPhotoChem 3, 327 (2019); Y. Kageyama Symmetry 12, 1688 (2020).

[5] H. Takahashi, Y. Kageyama, et al. Chem. Commun. 46, 8791 (2010).

Abstract without bibliography information:

The construction of life-like molecular-based robots is currently an attractive research target in supramolecular chemistry. For this purpose, “autonomy in chemical system” is