Atomization energies of phosphorus oxides

Abstract

The study by the mass-spectrometric Knudsen-cell method of the vapours in equilibrium with metal oxide + metal phosphide systems at 1000–1700 K made possible the identification of the molecules P₂O₃, P₂O₄, P₂O₅ and P₃O₆. Their atomization energies were determined, as well as those of the phosphorus oxides prevalent at low temperatures. These are : P₂O₃ : 2055±15, P₂O₄ : 2530±18, P₂O₅ : 3020±22, P₃O₆ : 4012±24, P₄O₆ : 4385 (+40, –60), P₄O₇ : 4956±23, P₄O₈ : 5516±25, P₄O₉ : 6066±27 kJ mol^–1.