Development of a Novel Physical Gelator consisting of a Mesogenic Structure : Use of "Fluorine-Hydrogen" Hydrogen Bonding

Abstract

Hydrogen bonding between fluorine and hydrogen has attracted a great deal of attention in computer and coordination chemistry. In the present study, "fluorine-hydrogen" hydrogen bonding has been applied for the first time to develop a novel gelator for organic solvents. We have designed and synthesized fluorophenol derivatives having a mesogenic core. The physical gels of common organic solvents such as chloroform, 1,2-dichloroethane, dodecane, benzene, and toluene have been obtained by the addition of 2,3-difluoro-4-[(4-pentylphenyl)phenyl]phenol. Liquid-crystalline physical gels of fluorinated liquid crystals are also obtained. The hydrogen-bonding ability has been studied by IR and ^<19>F-NMR measurements. X-ray single crystal structure studies reveal the existence of the "fluorine-hydrogen" hydrogen bonding.