A novel photochromic liquid crystal system based on biindenylidenedione derivatives

Abstract

A novel class of photochromic biindenylidenedione derivatives containing two mesogenic biphenyl units connected with flexible alkyl chains were designed and synthesized. All of them exhibited photochromism in solid states on UV-Vis irradiation accompanied by the simultaneous generation of stable organic radicals, two of them displayed monotropic liquid crystals properties. These were the first examples which had three different kinds of functional properties (photochromism, light-induced radical behavior and liquid crystal properties) in a pure compound. The correlation between the molecular structure, electronic factors and properties has been discussed.