Intramolecular co-ordination by a hydroxy-group to methylmercury(II). Synthesis and characterization of complexes [HgMe(L)]NO3 containing polydentate ligands (L), and the crystal structure of the tris(N-methylimidazol-2-yl)methanol complex

Abstract

Methylmercury(II) nitrate forms cationic complexes [HgMe(L)]NO₃[L = bis(N-methylimidazol-2-yl)methanol, bis(N-methylimidazol-2-yl)(pyridin-2-yl)methanol, or tris(N-methylimidazol-2-yl)methanol (tmm)]. The crystal structure of [HgMe(tmm)]NO₃ has been determined by single-crystal X-ray diffraction at 295 K and refined by least-squares methods to R= 0.041 for 2 453 ‘observed’ reflections. The [HgMe(tmm)]⁺ cations have one N-methylimidazol-2-yl group co-ordinated to mercury, with Hg–N 2.125(7)Å and C–Hg–N angle 176.1(5)°, together with an additional weak intramolecular Hg ⋯ OH interaction [2.680(6)Å]. Comparison of the ¹H n.m.r. spectra of the complexes with those of related complexes does not permit assignment of the co-ordination mode of the ligands, although multidentate co-ordination is indicated. Crystal data : monoclinic, space group P2₁/n, with a= 14.421 (4), b= 11.819(2), c= 10.985(3)Å, β= 107.41(2)°, and Z= 4.