Studies in cyclophosphazenes. Part IV. The kinetics of the reactions for the formation of methylaminodimethylaminotetrachlorocyclotriphosphazene in tetrahydrofuran

Abstract

The rates of two reactions leading to the formation of trans-methylaminodimethylaminotetrachlorocyclotriphosphazene, viz. The reaction of methylaminopentachlorocyclotriphosphazene with dimethylamine and the reaction of dimethylaminopentachlorocyclotriphosphazene with methylamine have been measured in tetrahydrofuran at various temperatures. The rate of the first reaction is almost equal to that of the reaction of dimethylaminopentachlorocyclotriphosphazene with dimethylamine and the rate of the second reaction roughly equals that of the reaction of methylaminopentachlorocyclotriphosphazene with methylamine. The conclusion which is reached from these comparisons is that the rates of these amination reactions are strongly dependent on the nucleophile but virtually independent of the nature of the amino-substituent on the ring. The electronic and steric implications of these conclusions are examined. Apparently similar conclusions relating to the influence of the nucleophile and the substituents on the ring, observed in a preparative study are discussed in the light of the kinetic data.