Synthesis of oligomeric chlorophosphazenes in the presence of ZnCl2

With the use of P-31 NMR spectroscopy and gas chromatography-mass spectrometry, the partial ammonolysis of PCl5 by ammonium chloride in chlorobenzene in the presence of zinc chloride is investigated. The use of zinc chloride reduces the reaction time to 1.5 h and increases the yield of oligomeric chlorophosphazenes up to 95%. Some assumptions are made about the role of ZnCl2 in the process and about the feasibility of the mechanism of formation of higher cyclic chlorophosphazenes, the hexamer and the octamer.