Nuclear magnetic resonance spectral analysis for spin systems involving threefold symmetry. The spectrum of N(PF2)3

Abstract

The [A[X]₂]₃ and [AX₂]₃ nuclear magnetic resonance spin systems are discussed and factorized energy-level diagrams for the D_3h variants presented. A computer program capable of computing spectra with threefold symmetry was written and used to analyse fully the ¹⁹F n.m.r. spectra of tris(difluorophosphino)amine, N(PF₂)₃, obtained at 300 and 223 K. The fluorines of each PF₂ group are effectively (but not necessarily actually) magnetically equivalent. The value of |²J_PP| is 100.5 Hz at 300 K, increasing to 113.0 Hz at 223 K.