Oxonium diimidotriphosphate from the hydrolysis of trimetaphosphimic acid

Abstract

Trimetaphosphimates decompose not only upon heating but also in water. Hydrolysis of trimetaphosphimic acid leads to the formation of diimidotriphosphoric acid by ring opening. Single-crystal structure determination using synchrotron radiation revealed the oxonium salt of the latter acid with double stacks of rod-shaped anions along [001]. Anharmonic displacement parameters were used to model slight disorder of part of the anions. These are interconnected by hydrogen bonds within and between the stacks. Powder X-ray diffraction confirmed phase purity. At temperatures above 120 °C, diimidotriphosphoric acid decomposes into unknown crystalline compounds. It thus seems a promising precursor for the synthesis of oxonitridophosphates at moderate temperatures.Graphical abstract