Mesogenic properties of nickel(II) complexes of N-(2-hydroxy-4-n-alkyloxybenzylidene)4''-n-dodecylphenylanilines

Restricted Access. Presented at the 14th international liquid crystal conference, 21-26 June 1992, Pisa, Italy.Continuing our efforts to synthesise metallomesogens to study the influence of different transition metals on the mesophases, a series of nickel(II) complexes of N-(2-hydroxy-4-n-alkyloxybenzylidene)-4''-n-dodecylphenylanilines have been prepared. These predominantly exhibit smectic A and smectic C phases. A comparison of the mesomorphic behaviour of these complexes with those of the corresponding copper(II) and palladium(II) complexes has been made. It was found that the palladium complexes have the highest thermal stability of the mesophase while the nickel complexes have the lowest melting points. Preliminary experiments on magnetic measurements have shown that these nickel complexes are diamagnetic in the solid state and exhibit paramagnetic properties in chloroform solution