INVESTIGATION OF A MERCURY(II) CARBENE COMPLEX - BIS(1,3-DIMETHYLIMIDAZOL-2-YLIDENE) MERCURY-CHLORIDE

The reaction of 1,3-dimethylimidazolium chloride with Hg(O2CCH3)(2) af forded a bis(carbene) mercury (II) complex (2), which is characterized by multinuclear NMR spectroscopy (H-1, C-13, N-15, and Hg-199) and by single-crystal X-ray analysis. As a consequence of chloride-ion inter action with the mercury center the C-2-Hg-C-2 angle in 2 is reduced to 161.4 (3)degrees compared to its near-linear value in complex 4 that contains perchlorate counterions. The C-2 resonance in the mercury com plex 2 moves upfield by 36.96 ppm relative to the parent carbene (2), with a large (1)J(HgC) = 2741.18 Hz. (C) 1996 John Wiley & Sons, Inc.