Dipole architecture of molecules and mesomorphic behavior of liquid crystals with rigid <Emphasis Type="Italic">T</Emphasis>-shaped mesogenic fragment

A number of liquid crystalline polyesters having a rigid T-shaped mesogenic fragment and differing in dipole architecture were synthesized and examined by polarizing optical microscopy, differential scanning calorimetry, and IR and ¹H NMR spectroscopy. The thermal stability of the mesophase in the given series of compounds was shown to increase with extension of arms in the T-shaped mesogenic fragment, as well as on replacement of the terminal ester groups (COOAlk) therein by ether moieties (OAlk). Such replacement also enhances smectogenic properties.