Thermal characteristics of fatty acid copper(II) carboxylate complexes with nicotinamide and diethylnicotinamide ligands

TG and DTA studies of [Cu2(OOCCnH2n+1)4(nia)2] (nia=nicotinamide;n=6–11) and [Cu2(OOCCnH2n+1)4(Et2nia)2](Et2nia=N,N-diethylnicotinamide;n=6–11) are reported. The influence of the ligands in these complexes on the solid-to-liquid crystalline phase transition is established. Solid-to-solid, solid-to-liquid crystalline and liquid crystalline-to-isotropic liquid phase transitions are confirmed for the compounds with nia ligand [(Cu2(OOCCnH2n+1)4(nia)2] (n=10,11) by variable temperature X-ray diffraction analysis and polarized optical microscopy. Only melting points are detected in all complexes with the Et2nia ligand.