Preparation and characterization by 31P-NMR spectroscopy of mixed disubstituted complexes

Article abstract of DOI:10.1016/0022-328X(90)85062-4

The disubstituted complexes , where L and L' are different phosphine ligands have been prepared by reaction of the hydrosilyl derivatives with L'.Good results were obtained for L = PMe3 and L' = PPh3, P(OPh)3, P(OEt)3 or P(O-i-Pr)3 but with L' = PMe2Ph, PMePh2, PEt3, a mixture of homo and mixed disubstituted derivatives were obtained.The results can be interpreted in terms of exchange of the L ligand in 3 with L'.The variations in the 31P<1H> NMR chemical shifts and ²J_PP coupling constants are discussed in the light of the properties of the ligands, and good correlations are revealed with the cone angle and the pK_a, respectively.