Carbon-13 nuclear magnetic resonance study of methyl- and phenyl-mercury(II) compounds

Abstract

The ¹³C chemical shifts of the methyl carbon in a wide range of compounds of methylmercury(II) and of the phenyl-ring carbons in several phenylmercury(II) compounds (HgRX) have been observed and rationalised. Direct carbon-13–mercury-199 couplings, ¹J(C–Hg), have also been observed in most of the compounds and are strongly dependent on the solvent as wall as on the nature of the unidentate ligand X, as are the corresponding two-bond proton-mercury couplings, ²J(H–Hg). Some very large values of ¹J(C–Hg) have been observed, {e.g. 2 661.1 Hz for phenylmercury(II) acetate in [²H₆]dimethyl sulphoxide}. The observed variations of coupling constant are explicable either by a rehybridisation scheme or by a departure from strict molecular linearity in nucleophilic solvents.