Synthesis and thermal properties of mesomorphic 1,1′-bis[ω-(4′-cyano-4-biphenyloxy)alkyl] ferrocenes

Abstract
A new series of 1,1′-disubstituted ferrocene compounds of the type [(η5-C5H4(CH2) n OC6H4C6H4CN]2Fe (3a–d, n = 5, 6, 8, 11) incorporating a variable length alkyloxy cyanobiphenyl unit has been prepared and their mesomorphic properties have been investigated. Compounds 3b, c and d exhibit a thermotropic smectic C phase and 3c also exhibits a monotropic smectic A phase over a fairly wide range near ambient temperature.