Phosphorus-31, cadmium-111, cadmium-113 and mercury-199 N.M.R. studies of cadmium(II) halide and mixed cadmium(II)-mercury(II) halide complexes with tributylphosphine

Phosphorus-31, cadmium-111 and cadmium-113 n.m.r, studies have been carried out on CdX2(PBu3)2 (where X = Cl, Br, I). The results are consistent with exchange of both phosphine and halogen. Phosphine exchange becomes slow on the N.M.R. time scale in all cases by -40°C. Mixtures of CdX2(PBu3)2 with different halogens give averaged signals at room temperature, but below about -80°C exchange becomes slow and halogen redistribution reactions can be observed. ��� Reaction of CdX2 and PBu3 in 1 : 1 proportions in ethanol gives Cd2X4(PBu3)3 as the isolated product, not Cd2X4(PBu3)2. It is shown that ethanol is an effective ligand to cadmium and redistribution reactions between coordinated ethanol and the phosphine occur. ��� The mixed metal complexes CdHgX4(PBu3)2 have been shown by phosphorus-31, cadmium-113 and mercury-199 n.m.r, studies to have all the phosphine coordinated to mercury. ��� Cadmium-111 and cadmium-113 chemical shifts in these compounds span a range of over 500 ppm and shifts have been correlated with 31P chemical shifts and the coupling constant JP,Cd.