Cu FT-NMR Studies of Tetrahedral Copper(I)-Phosphorus Complexes

Tetrahedrally coordinated copper(I) complexes C11L4X have been synthesized, L being P(OR)3, PR3 or P(R)n(OR)3-n, and X being a non-coordinating anion such as Perchlorate or tetrafluoroborate. Depending on the nature of the bound phosphorus ligand the Cu(I) complexes give well resolved 63Cu NMR spectra including a quintet signal due to spin-spin coupling between 63Cu and 31P. The 63Cu NMR spectra have been analyzed with reference to the chemical shift (), the shielding constant a* (given on an absolute atomic scale), the linewidth Av, and the coupling constant J(63Cu-31P). Generally, the relative magnitude of these NMR parameters are in satisfactory agreement with results reported for isoelectronic Ni(O) complexes with the phosphorus ligands mentioned above. Furthermore, the NMR properties of the Cu(I) compounds are discussed in terms of cr-donor or 7r-acceptor capacities of the ligands coordinated, and stereochemical properties of the complexes.