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