Modulated and intercalated smectic phases formed by dimeric molecules

Abstract

A series of molecules having a hydroxyl group attached to the end of one terminal chain were found to form a sequence of smectic antiphases, SmÃ, Sm, Sm and Cr, with a growing degree of in-plane molecular ordering. The bilayer structure of the modulated phases is due to the formation, through hydrogen bonding, of molecular dimers that are linear in shape. Moving the hydroxy group to a position closer to the molecular core resulted in a similar sequence of non-modulated, monolayer smectic phases. The related dimeric compounds in which the same mesogenic cores were covalently linked by an alkyl chain formed intercalated smectic phases.