Mesomorphic phase transition in organophosphazenes

Organophosphazenes with similar mesogenic moieties were prepared and their mesogenicity was studied by use of DSC measurements and polarizing microsco pe observations. In cyclotriphosphazenes with octyloxybiphenyl moieties, me somorphic phase transitions of Cr-SmC-I were observed, but no mesomorphic p hase was observed for the corresponding tetramer and polymer. In cyclotriph osphazenes and cyclotetraphosphazenes with Schiff base moieties, enantiotro pic mesomorphisms of Cr-Sml-SmC-SmA-I and Cr-SmA-I were observed. In polyph osphazenes with similar Schiff base moietities, a mesomorphic phase was obs erved. A higher mesomorphic ability of the Schiff base moieties than those of alkoxybiphenyl reflects on the phase transition of organophosphazenes. T he molecular structure and mesogenicity was discussed in the organophosphaz enes with similar alkoxybiphenyl side groups.