Dynamics of hydrogen-bonded molecular assemblies and their physical properties

Dynamic molecular materials have been designed by focusing on the intermolecular hydrogen-bonding interaction in molecular assemblies. For instance, one-dimensional and two-dimensional columnar amide-type hydrogen-bonding interactions of aromatic oligoamide (-CONHC_nH_2n+1) derivatives were responsible for the external electric field in liquid crystalline state, which induced the polarization inversion and ferroelectricity. Multi-functional ferroelectric organic materials such as fluorescent-ferroelectrics and current switching-ferroelectrics were designed by choosing in a central π-electron core. Mechanically thermoresponsive crystalline materials with high thermal stability were also obtained by designing in the hydrogen-bonding array of dynamic π-molecular system. Through the precise designs of dynamics in molecular assemblies including in the functional π-electron system, "bulk dynamic" properties such as ferroelectricity and thermosalient behavior were coupled with the intrinsic π-electronic properties such as electrical conducting, magnetic, and optical properties. Such multi-functional organic materials have a potential to construct a new molecular science.