THERMOTROPIC LIQUID-CRYSTALLINE PROPERTIES OF 1,2,PSI,OMEGA-N-ALKAN-TETRAOLS

A homologous series of biamphiphilic 1,2,psi,omega-alkan-tetraols has been synthesized. They form lamellar thermotropic liquid crystalline p hases which have been studied by polarizing optical microscopy, as wel l as by X-ray investigations. Those compounds with a rather long polym ethylene chain between the two diol groups exhibit a lamellar cc phase and an additional low temperature mesophase, whereas short chain deri vatives exhibit only the low temperature mesophase. From X-ray measure ments, we conclude that this low temperature mesophase is a highly ord ered phase in which the chains are rigid and tilted with respect to th e hydrogen bonding networks.