The structure and spectroscopic characterization of coordination compounds with -phenyl-N-methylnitrone in solution and in solid state

Abstract

New coordination compounds of a-phenyl-N-methylnitrone with Cu2+, Mn2+, Ni2+, and UO22+ were synthesized. Complexes were studied by means of IR, NMR and UV-Vis spectroscopies. The crystal and molecular structure of uranyl complex with a-phenyl-N-methylnitrone was determined by X-ray diffraction study. The monodentate nitrone ligands are coordinated to the metal ion via oxygen atom. The coordination polyhedron of uranium is a distorted hexagonal bipyramide. It was shown that there is dynamic process in the acetone solution in the temperature range of 203–297 K. The ligand exists as a trans-isomer for both present forms of organic ligand by the NOE difference. Dimeric copper(II) benzoate was obtained via recrystallization of the copper complex with a-phenyl-N-methylnitrone from methanol solution. According to X-ray diffraction analysis, the environment of each of the copper atoms is octahedral. The coordination sphere is formed by six oxygen atoms. Three anions of benzoic acid are coordinated bidentate-bridged through oxygen atoms of the carboxyl group, while one molecule of benzoic acid is coordinated monodentatically through the carboxyl oxygen atom.