Phosphorus–nitrogen compounds. Part XXX. The reaction of phenylmagnesium bromide and diphenylmagnesium with octachlorocyclotetraphosphazatetraene

Abstract

Octachlorocyclotetraphosphazatetraene, N₄P₄Cl₈, reacts with phenylmagnesium bromide in various solvents, but much more slowly than its lower homologue, N₃P₃Cl₆. Cyclic compounds are the major products, but acyclic phosphazenylmagnesium complexes are also observed. The two principal reaction products are structural isomers of formula N₄P₄Ph₄Cl₄, whose relative yields are very sensitive to the nature of the solvent. One of the products is a geminal tetrachlorotetraphenylcyclotetraphosphazatetraene, whose structure is discussed, the other, 2,2,4,4-tetrachloro-6-phenyl-6-phenyl-6(2′,2′,2′-triphenylphosphazen-1′-yl)cyclotriphosphazatriene. When diphenyl-magnesium is employed as reagent no new products appear. A mechanism is suggested which accounts for the observed products and the effect of solvent basicity on the course of the reaction.