Studies of phosphazenes. Part 4. Reactions of octachlorocyclotetraphosphazatetraene with t-butylamine

Abstract

The reaction of octachlorocyclotetraphosphazatetraene, N₄P₄Cl₈, with t-butylamine yields the derivatives, N₄P₄Cl_8–n(NHBu^t)_n[n= 1,2 (two isomers), 3, and 8][(2)–(6)] and N₄P₄(NHBu^t)₈·HCl (7). Resin formation is a prominent feature of many reactions and attempts to prepare the derivatives N₄P₄Cl_8–n(NHBu^t)_n(n= 4–7) have been unsuccessful. Phosphorus-31 n.m.r. spectroscopy establishes 2,4- and 2,6-structures for the bis-isomers [(4) and (3)]. The tris-compound (5) also has a non-geminal structure. ¹H and ³¹P n.m.r. data for the hydrochloride (7) show that the exchange of the proton is slow on the n.m.r. time scale at ambient temperature. The t-butylamino(ethylamino)-derivatives, 2,6- and 2,4-N₄P₄Cl₆(NHBu^t)(NHEt)[(12) and (13)], have been pre-pared. The relative yields of these isomers and also of the isomers (3) and (4) vary markedly with the reaction solvent. The dominant role of the nucleophile in determining the course of halogen-atom replacement in the aminolysis reactions of N₄P₄Cl₈ is inferred.