Variable temperature carbon-13 and mercury-199 NMR examination of cyclohexylmercury systems

Abstract

The variable temperature carbon-13 and mercury-199 nmr spectra of some cyclohexylmercurials. C 6H 11HgX (X = -OCOCH 3. -CN, -C 6H 11 and -C 6H 5) have been recorded and assigned by consideration of chemical shifts, 199Hg- 13C coupling constants and comparisons with the data For 4-methylcyclohexyl derivatives of established constitution. These studies confirm the axial preference for the mercury groups (HgX) examined, although X does influence the conformational equilibrium to a minor extent. For dicyclohexylmercury, three arrangements about mercury are possible and anticipated ( a, a; e, e; a, e), and at low temperatures signals appropriate for the three species are detected in the 13C spectra. Some 199Hg chemical shifts for related miscellaneous compounds are also presented, and equatorial mercury groups resonate 80–100 ppm to higher field of the corresponding axial groups.