Equilibrum and Nonequilibrium Chemical Reactions of Helicene Oligomers in the Noncovalent Bond Formation

Chemical reactions involving noncovalent bond formation are discussed with regard to the equilibrium and nonequilibrium states: An equilibrium-to-equilibirum chemical reaction involves change of equilibrium states by changing the environment; a nonequilibrium-to-equilibrium reaction involves change of metastable state to equilibrium. Complex nature of the chemical reactions, especially in the latter, is shown in terms of the multiple-path nature in the microscopic molecular structure changes and macroscopic concentration changes. Irreversible and reversible nonequilibrium-to-equilibrium chemical reactions are also compared in terms of the multiple-path. Helicene oligomers, which reversibly form double-helix and random-coil by temperature changes, are discussed with regard to the reversible nonequilibrium-to-equilibrium chemical reaction with self-catalysis, where notable chemical phenomena appear under nonequilibrium conditions.