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, RnPF5–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.