Investigation of structural characteristics of bis(beta-diketonato)copper(II) complexes containing alkoxy or aryloxy side chains: X-ray structures of1,3-bis(4-butoxyphenyl)propane-1,3-dione, bis[1,3-bis(4-butoxyphenyl)propane-1,3-dionato-kappa O,kappa O ']copper(II) and bis[1,3-bis(4-phenoxyphenyl)propane-1,3-dionato-kappa O,kappa O ']copper(II)

Copper(H) complexes containing beta -diketonato ligands of the general form ula [Cu{(4-RO)C6H4COCHCOC6H4(4-OR))(2)] 3 (R = Bu) or 4 (R = Ph) were prepa red and their structures solved by X-ray diffraction. The crystal structure of the parent ligand (4-BuO)C6H4COCH2COC6H4(4-OBu) 1 was also solved, The influence of the different side chains 4-RO-C6H4 (R = Bu or Ph) on potentia l liquid-crystal properties was investigated for both the ligands and the c opper derivatives. The presence of BuO substituents at the aromatic rings a ppears to improve the molecular linearity with respect to 1,3-diphenylpropa ne-1,3-dione (=dibenzoylmethane; DBM), this feature being of interest for r od-like structures. On the other hand, the molecular structure of the coppe r(II) complexes 3 and 4 showed a flat core almost unmodified by the differe nt peripherical substituents, A columnar arrangement was observed for both compounds 3 and 4, but, additionally, a layer-like disposition was also fou nd in 3, which was proved to be a metallomesogen.