Mesomorphic Behaviour of Optically Active Anils: 4-n-Alkoxybenzylidene-4'-Methylalkylanilines
Hsu, Y.Y. and David Dolphin
Liq. Cryst. Ordered Fluids
The preparation and the effects of the position of the Me group and the chain length on the liquid-crystal and optical properties are described for the title compounds. Thermodynamic data for the transitions is given. The addition of the Me group lowers the mesomorphic-isotropic transition temperature but does not consistently affect the solid-mesomorphic transition temp. An odd-even alteration of the chiral nematic-isotropic temperature occurs as the alkoxy chain length increases. The effects of branching chains for different homologous series are described. Increasing the length of the alkylaniline chain causes a decrease in the refractive indexes and an increase in the optical pitch.