Phosphorus–fluorine chemistry. Part XXIX. Reaction of aminosilanes and N-alkyl(or aryl)hexamethyldisilazanes with fluorophosphoranes: chemical and spectroscopic studies on dialkylaminofluorophosphoranes and fluoro-1,3,2,4-diazadiphosphetidines

Abstract

The reaction of phosphorus pentafluoride and its organic derivatives, R_nPF_5–n(n= 1,2) with NN′-disubstituted aminotrimethylsilanes. R₂N·SiMe₃, provides a facile method of synthesis of fluorophosphoranes of types R₂NPF₄, (R₂N)₂PF₃, RPF₃NR′₂, and R₂PF₂NR′₂. When PF₅ and RPF₄ are allowed to react with N-substituted hexamethyldisilazanes, RN(SiMe₃)₂, the cyclic fluorophosphoranes, [RNPF₃]₂ and [R′NPF₂R]₂, are formed. Diphenyltri-fluorophosphorane with MeN(SiMe₃)₂ gives only a monomeric fluorophosphine imide, MeNPFPh₂. All the compounds reported are of stereochemical interest, as derivatives of phosphorus pentafluoride. Their ¹H, ¹⁹F, and ³¹P n.m.r. spectra are presented and discussed.