Liquid Crystalline Phase Transition of Cyclotriphosphazenes Bearing Shiff Base Side Chains

Abstract

A series of cyclotriphosphazenes having shiff base side chains, hexakis(4-(N-(4'-alkyloxyphenyl)iminomethyl)phenoxy)cyclotriphosphazene(HAICP) [((C_dH_2n+1OC₆H₄CN=HC₆H₄O)₂PN)₃, n=4-12] were newly synthesized and their phase transitions were studied by DSC and polarizing microscope observation. We found a S_B phase in n=4 and 5, S_B, S_C, S_A phases in n=6, S_C and S_A phases between 7 and 10, S₁, S_C and S_A phases in n=11 and 12, respectively. S₁ is a higher order opotically biaxial smectic phase.