One-dimensional bimetallic cyano complexes with nicotinamide and isonicotinamide ligands

Two new 1D bimetallic Cu(II)/Ni(II) coordination polymers, {[Cu(NH3)4(μ-na)][Ni(CN)4]}n (1) and {[Cu(NH3)2(ina)2Ni(μ-CN)2(CN)2]}n (2) (na: nicotinamide, ina: isonicotinamide) have been synthesized and characterized by vibrational (FT-IR and Raman) spectroscopy, elemental, thermal analyses, and single crystal X-ray diffraction techniques. In both of the complexes, Ni(II) ion is four coordinate with four cyanide–carbon atoms in a square-planar geometry. In 1, the [Ni(CN)4]2− ion acts as a counter-ion, whereas it coordinated to the Cu(II) ions as a bridging ligand in 2. In 1 and 2, each Cu(II) ion is coordinated in a distorted octahedral geometry. Single crystal X-ray analysis showed that 1 and 2 exhibit one-dimensional linear chain running along the crystallographic a-axis and b-axis direction, respectively. Adjacent chains are further stacked through intermolecular hydrogen bonding, NH⋯π, CH⋯Ni and Ni⋯π interactions to form 3D supramolecular network.