The control of reaction rates and equilibria is central to modern chemical sciences. To realize this, a wide variety of sophisticated reagents, catalysts and methodologies have been developed in the last century. However, in developing these tools and in discussing the factors governing rates and equilibria, the enthalpic contribution has traditionally been more, or over-, emphasized, whilst the entropic contribution has not explicitly or extensively been considered in general to play a crucial role. In contrast, living organisms employ a more smart strategy, controlling biological reactions and equilibria not by enthalpy, but through entropy.
In this cooperative research project, we have revealed that the entropy-related factors and therefore the weak interactions indeed play the decisive roles particularly in supramolecular and photochemical processes. Consolidating the knowledge, experience and research potentials of the two research groups, the Japan-Korea binational team has establish a novel multidisciplinary region of science, i.e. "Entropy Control." Based on this new concept, we have developed the highly effective photochirogenic systems that achieve 100% optical yield, the versatile chiroptical sensors based on bis-porphyrinoids, and the extremely stable, 100% entropy-controlled supramolecular systems comparable to the avidin-biotin pair, the nature’s strongest binder.
The concept of "Entropy Control" is expected to widely contribute to the reaction design under mild conditions, the synthesis of useful chiral compounds, the development of supramolecular nanomaterials, and the environmentally benign chemistry in aqueous and supercritical media in various chemistry-related industries, and ultimately switches our social mind from “save energy” to “decelerate the entropy increases.”