31P-Kernresonanzspektrometrische Untersuchungen an Phosphato-Cobalt(III)- und Rhodium(III)-Komplexen

³¹P N.M.R. Spectroscopic Investigations of Phosphato Complexes of Cobalt(III) and Rhodium(III) ³¹P n.m.r. spectra of phosphato complexes of cobalt and rhodium(III) are recorded. The coordination shift of monodentate phosphate is 8–9 ppm, of bidentate phosphate 18 ppm, of phosphite 10–11 ppm, of fluorophosphate 6–7 ppm. Monophosphato and pentaamminaquacobalt complexes condense with the elimination of water to a m?-complex. The ability of the phosphato complexes of cobalt(III) to condense phosphate to diphosphate was investigated. After heating CoPO₄en₂] · 2 H₂O with an excess of dihydrogenphosphate only small amounts of the expected diphosphate complex could be detected. The analogous reaction with fluorophosphate results in an appreciably higher yield of the diphosphate complex.