Synthesis and Some Physical Properties of Unsymmetrical 4,4′-Dialkylazoxybenzenes

Two series of unsymmetrical 4,4′-dialkylazoxy compounds: have been obtained, where K = C m H2m+l with m = 2 to 10. The method of their synthesis and the results of measurements of the phase transition temperatures, dielectric constants, refractive indices and densities are presented. Compounds I and in a lesser degree compounds II are low-melting nematics with a small positive anisotropy of the dielectric constant. In both series a strong alteration was observed of clearing point, dielectric constant anisotropy Δε and birefringence Δn with the number in ofcarbon atoms in the alkyl radical.