Syntheses and Physical Properties of Ferrocene Derivatives (VII) PhaseTransition Behavior and Liquid Crystal Structure of 1,1′-Disubstituted Ferrocene Derivatives

Abstract

Liquid crystalline 1,1′-disubstituted ferrocene derivatives, 1,1′-bis[ω-[4-(4′-methoxyphenoxycarbonyl)phenoxy]alkoxycarbonyl] ferrocene (abbreviated hereafter to bMAF-n, n = 2∼12, where n is a carbon number of the methylene chain units), were synthesized, and their phase transition behavior was studied using a differential scanning calorimeter and a polarizing microscope. The liquid crystal structures of the compounds were investigated by the X-ray diffraction method. Nine of eleven compounds of the samples showed liquid crystallinity. The liquid crystalline phases were identified as a nematic (n = 3 and 5∼12), a smectic C (n = 5∼12) and a smectic F or I (n = 11 and 12). As a model structure of the smectic phase, a tilted structure with an expanded substituent is presented.

Key Words:

• Ferrocene
• liquid crystal
• metallomesogen
• disubstituted derivatives
• phase transition