Mixed-Ligand Cobalt(II) and Nickel(II) Complexes with N,N,-Diethylpyridine-3-carboxamide: Synthesis and Crystal Structure

The new complexes [M(NKA)(2)(NCS)(2)(H2O)(2)], where M2+ = Co2+ (I), Ni2+ (II); NKA = C10H14N2O (N,N-diethylpyridine-3-carboxamide, nicotinic acid diethylamide, nikethamide), have been synthesized and studied by chemical and X-ray diffraction analyses and IR spectroscopy. The single-crystal X-ray diffraction analysis of these complexes has shown that they crystallize in triclinic system with space group P (1) over bar. Despite similar molecular structures of the two complexes, the orientation of molecules in a crystal cell is different in them. The coordination polyhedron of the metal atom is a distorted octahedron built of the O atoms of two coordinated water molecules, the two N atoms of the pyridine rings of two NKA molecules, and the two N atoms of rhodanide groups. The packing of molecules leads to the appearance of additional stacking interactions with the formation of a branched network of hydrogen bonds between coordinated water molecules and NKA carbonyl groups in the structures of these complexes.