Determination of 113Cd shielding tensor components in cadmium-phosphine complexes from 31-decoupled 113Cd cross-polarisation/magic angle spinning spectra

Abstract

Owing to the simultaneous presence of various anisotropic interactions within the isolated M- 31P and M( 31P) 2 fragments in solid transition metal phosphine complexes MX 2 · PR 3 and MX 2 · 2PR 3 with, for instance, M = Cd, Hg or Pt, it is not normally possible to unequivocally determine the shielding tensor components of the metal nucleus M from simple 113Cd, 199Hg or 195Pt cross-polarisation/magic angle spinning (CP/MAS) spectra. In this paper it is shown that additional 31P on-resonance high-power decoupling during the acquisition time does allow the determination of the shielding tensor components of M from CP/MAS spectra. Two cadmium(II) complexes, Cd(OAc) 2 · Pchex 3, (chex = cyclohexyl) and Cd(ClO 4) 2 · 2Pchex 3 were chosen as examples; the 113Cd CP/MAS experiments were carried out at a low external magnetic field strength B 0 = 2.35 T.