Cis, cis -(3,5-dihydroxycyclohexyl) 3,4-bis(alkoxy)benzoates Thermal behaviour and water absorption

A homologous series of liquid crystalline cis, cis-(3,5-dihydroxycyclohexyl) 3,4-bis(alkoxy)-benzoates ('two chain' diols) is described. The formation of different mesophase structures by these compounds is influenced by the length of the alkoxy side chains; changes from smectic via cubic to hexagonal columnar mesophases have been established in a certain chain length range. The aggregation to 'supramolecular' structures via hydrogen bonding seems to be necessary for the different mesophases. Not only the behaviour of the freeze dried products, but also that of samples which had absorbed water, either from a saturated atmosphere or from direct contact, is described.