Abstract
Several benzoic acid derivatives having perfluoroalkyl substituents are synthesized and hydrogen bonded complexes with 4,4'-dipyridyl are prepared. In these complexes incompatibility between perfluoroalkyl moieties and hydrocarbon parts is large, which leads to form nano-segregation structures. We have found in one of such complexes having a long flexible fluorinated moiety a thermotropic cubic phase with la3d symmetry. Furthermore another complex having an end-branched long perfluoroalkyl substituent exhibits a first order smectic C to smectic A phase transition, which is confirmed with DSC measurements detecting a large enthalpy change of 5.5 KJ-mol^<-1>, X-ray scattering experiments revealing a tilt angle jump, and polarized optical microscopy exhibiting a remarkable texture change at the phase transition temperature.
