Mass spectrometric studies on cyclo- and poly-phosphazenes: 3—Polymerization of tris(o-diphenylenedioxy)cyclotriphosphazene, [NP(O2C6H4)]3

The polymerization reaction of tris(o-phenylenedioxy)cyclotriphosphazene, [NP(O₂C₆H₄)]₃, occurs in the ion chamber of a mass spectrometer under high-sample vapour pressure conditions, leading to the formation of tetrameric, pentameric and hexameric species. There is evidence that, under electron impact conditions, the phosphonitrilic ring of [NP(O₂C₆H₄)]₃ breaks down, giving rise to a linear phosphazene radical cation, from which the polymerization reaction takes place by means of successive additions of neutral NP(O₂C₆H₄) units. A comparison is made between this reaction and mass spectrometrically induced polymerizations of hexachloro- and hexa(phenoxy)-cyclophosphazenes, previously reported.