Cu-63 P-31 coupling constants and Cu-63 quadrupole couplings from P-31 CP/MAS spectra of copper (I)-phosphine complexes with aryldithiocarboxylates or benzoate

Magic-angle spinning P-31 NMR spectra of solid [CuS2C-Ph(PPh3)(2)] 1, [{CuS2C-pT}(4)(PPh3)(2)] 2, [{CuS2C-Ph}(4)(PPh3)(3)] 3, [CuS2C-Ph(dppm)](2) 4 and [CuO2C-Ph(dppm)](2) 5, (T = tolyl, dppm = bis(diphenylphosphino)methane) were obtained at 109.6 MHz. They consist of distorted quarters from non-equivalent phosphorus atoms and provide approximate values of the indirect spin-spin coupling constant (1)J[(CU)-C-63,(31)p], that are indicative of the covalency of the dithiocarboxylate-copper bonding. The spacing distortions are related to a number of molecular and structural parameters and thereby allow an estimation of the copper quadrupole coupling constant e(2)qQ/h which, as expected, is smaller for tetra-coordinated (1, 2, 3 and 4) than for tri-coordinated (5) copper sites. The spectrum of 2 has been successfully simulated (including the isotope effects from the less abundant (CU)-C-65 isotope) using the full theory for calculation of the spin eigenfunctions of the quadrupolar nucleus. (C) 1997 Elsevier Science B.V.