Studies of phosphazenes. 12. Reactions of N₄P₄Cl₈ with dibenzylamine- isolation of an unusual "bicyclic" phosphazene, N₄P₄[N(CH₂Ph)₂]₆(NCH₂Ph)

Abstract

Octachlorocyclotetraphosphazene, N₄P₄CI₈, reacts with dibenzylamine to give the chloro(dibenzy1amino) derivatives, N₄P₄C1₈[N(CH₂Ph)₂]_n = 1, 2 (two isomers), and 4 (three isomers). Nongeminal structures have been assigned to these compounds on the basis of ¹H and ³¹P NMR spectra. The presence of at least two tris(dibenzylamin0) derivatives in some reaction mixtures is also inferred from NMR spectra. Steric effects become important at the tetrakis stage of chlorine replacement, and further substitution by dibenzylamine to give monocyclic tetrameric derivatives does not occur. A "bicyclic" phosphazene, N₄P₄[N(CH₂Ph)₂]₆(NCH₂Ph), is obtained from the reaction of N₄P₄Cl₈ with an excess of dibenzylamine in boiling methyl cyanide. The formation of this derivative and its spectroscopic data are discussed.