Liquid-Crystalline Properties of 5,5′-Dialkyl-2,2′:5′,2″-Terthiophene and its π-Complexation with Cp*Ru

Abstract

A series of dialkylterthiophenes, CH₃(CH₂)_n-TTh-(CH₂)_nCH₃ (TTh ˭terthiophene, n=3,5,7,9,11) were synthesized and characterized. All the dialkyl-substituted terthiophenes display smectic mesophase except dibutylterthiophene exhibiting only a crystal melting. The thermal stability of the mesophase of dialkylterthiophene increases with increasing the length of alkyl chains. The complexation of the dialkyl terthiophenes with Cp*Ru suppresses liquid crystallity and all the complexes becomes amorphous.