Dimethyl Sulfoxide Complexes of Chromium(Iii), Manganese(Ii), Iron(Iii), Nickel(Ii), and Copper(Ii) Nitrates and Magnesium and Nickel(Ii) Perchlorates. Part 1. Preparation and Nuclear Magnetic Resonance and Infrared Studies

摘要

Dimethyl sulfoxide ((CH3)2SO, DMSO) complexes of Cr(NO3)3, Mn(NO3)2, Fe(NO3)3, Co(NO3)2, Ni(NO3)2, Cu(NO3)2, Ni(ClO4)2, and Mg(ClO4)2 were prepared and investigated using infrared and nuclear magnetic resonance (nmr) spectroscopy. The infrared data indicate that the ligand forms a coordinate bond to the metal through the oxygen atom in all of the complexes, and that the tetranitrato-metal anion is present in Mn(NO3)2.3DMSO, Co(NO3)2.3DMSO, and Cu(NO3)2.3DMSO. The nmr spectra of Mn(NO3)2.3DMSO, Co(NO3)2.3DMSO, Ni(NO3)2.4DMSO, and Cu(NO3)2.3DMSO in DMSO solutions were analyzed in terms of contact shifts, and electron-nuclear hyperfine coupling constants. The results correlate with the covalent-bond strengths of the metal atoms and fit a model for electron-spin delocalization via the sigma-bond system of the complexes. Attempts to utilize liquid SO2 as a solvent for the nmr studies were hampered by a reaction between SO2 and the nitrate ion. Literature references to DMSO complexes and to techniques used in their study are presented in two appendixes. (Author)