ELECTRIC BIREFRINGENCE IN SOLUTIONS OF BIS-4-CYANO-BIPHENYLOXYALKANES

The electrooptical properties of 4,4'-biscyanobiphenyloxyalkanes in di oxane and benzene were investigated by the method of equilibrium elect ric birefringence. A non-monotonic dependence of the Kerr molar consta nt of these compounds on the length of the oxyalkane spacer was found. This dependence is due to the influence of the odd-even effect on the intramolecular orientational polar and anisotropic order. The problem s are discussed of the effect of equilibrium and kinetic spacer flexib ility on the value and sign of the observed birefringence and on the d egree of correlation in orientations of mesogenic chain fragments in a n electric field.