Phosphites of some trivalent metals from the first transition series

Abstract

The phosphites M2(HPO3)3 . 7H2O (M = V, Cr), MH3P2O6 . 3 H2O (M = V, Mn) and H3[Cr(HPO3)3 . 10 H2O were studied in the solid phase by means of the thermography, magnetochemistry, and spectroscopy (IR, EPR, electronic reflection) techniques. The EPR spectrum of V2(HPO3)3 . 7H2O at ambient temperature displays hyperfine splitting arising from the nucleus 51V. In the phosphites H3[Cr(HPO3)3] . 10H2O, MnH3P2O6 . 3H2O, and probably also VH3P2O6 . 3H2O, in contrast to the other hithero studied hydrogenphosphites, coordination of the HPO2-3 anions occurs. These anions from which the molecules of the crystal water hydrogen bonds of the energy 40kJ mol-1. The Jorgensen's parameters of the ligand in the tris(phosphito)chromate(III) anion are f = 0.95 and h = 1.50.