Synthesis, characterization, and crystal structure of a Ni(II) complex of an acyclic pentadentate Schiff base; an agreement between the experimental and theoretical results

摘要

A Ni(II) complex of an acyclic pentadentate Schiff base was prepared by template condensation of two equivalents of 2-acetylpyridine with one equivalent of bis(3-aminopropyl)amine in the presence of Ni(II) in methanol. The resulting complex, [NiL_(33)(MeOH)](ClO_4)_2 centre dot CH_3OH, was characterized by X-ray crystallography, elemental analysis, and IR spectrophotometry. The X-ray crystallographic structure revealed a six-coordinate, distorted octahedral geometry in which the sixth coordination being achieved by a methanol molecule. A theoretical study at DFT (B3LYP) level using standard 6-31G basis set for ligand atoms and LanL2DZ for metal showed that the experimentally determined structure of the cation is about 8-20 kcal mol~(-1) more stable than its geometrical isomers.