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A detailed study into the synthesis and characterization of achiral nonsymmetric dimeric bidentate ligands formed by combining salicylaldimine and cyanobiphenyl rodlike anisometric segments through a flexible spacer (varying in its length and parity) and their Cu(II) and Pd(II) complexes is reported. The spacer parity greatly influences the phase behavior of ligands; notably, the dimers with odd-parity spacer stabilize nematic, uniaxial smectic A and biaxial smetic A phases, while the even-members display nematic and / or smectic phase/s. Unlike ligands, both the metal complexes solely show nematic behavior. An odd-even effect, as noted for ligands, was observed for the nematic-isotropic transition temperatures and the associated entropy values of copper complexes, while such behavior was not found in the case of palladium complexes. Chart 1 Molecular structure of the most extensively studied nonsymmetric dimers (CBOn.Om series; see ref. 2 and 4).

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