Host−Guest Monolayers of Cobalt Complex of Octaalkoxyphthalocyanines with Nematic Liquid Crystals

Abstract

Novel mixed monolayers consisting of metallophthalocyanines and nematic liquid crystals are described. When a mixture of a phthalocyanatocobalt with eight long-chain alkoxy residues and a nematic liquid crystal was spread on a water surface, a homogeneous monolayer was formed under critical conditions. Although homogeneous hybrid monolayers were obtained from a mixture of the metallophthalocyanine as a host and a normal alkane as a guest at an optimum mixing ratio of 1:7, as revealed in our previous work, large excess amounts of liquid crystal molecules were incorporated in homogeneous host−guest monolayers due to a long-range order of mesophasic molecules. A subphase temperature was required to be set at temperatures where guest molecules are in a liquid crystalline phase. The perpendicular orientation of guest molecules was confirmed by employing liquid crystalline azobenzene, 4,4‘-dihexyl-azobenzene, as a probe compound.