Transition Metals Complexed to Ordered Mesophases. Synthesis and Mesomorphic Properties of a Homologous Series of N-(4-Dodecyloxysalicylidene)-4'-Alkylanilines Complexed to Palladium(II)

The new [N-(4-dodecyloxysalicylidene)4'-CnH2n+1-aniline] palladium (II) derivatives, (R(n)L)(2)Pd, (1-6: n = 1-4,6,8 respectively) have been synthetized and their mesomorphic properties investigated by optical microscopy, DSC and X-ray diffraction measurements. Complexes 1-6, but 4, display a monotropic (1,5) or enantiotropic (2,3,6) smectic A mesophase. In 1-6 the geometry of the metal coordination sphere is square planar and with reference to homologous (R(n)L)(2)M compounds the mesomorphism of 1-6 appears at temperatures higher than for (R(n)L)(2)VO (distorted square pyramidal) or (R(n)L)(2)Cu (distorted square planar).