Crystal structures of N,N,N',N'-Tetramethylthiuram monosulphide and Diiodo(N,N,N',N'-tetramethylthiuram monosulphide)mercury(II)

Abstract

The crystal structures of the title compounds, Me₂NC(S)SC(S)NMe₂ (tmtm) and I₂Hg(tmtm), have been determined by single-crystal X-ray diffraction at 295 K and refined by full-matrix least squares to residuals of 0.038 and 0.050 respectively for 1080 and 1532 ?observed? reflections.     The ligand tmtm is monoclinic, P2₁/a, a 14.096(4), b 7.457(3), c 10.178(3)Ǻ, β 110.55(3)°, Z4. The complex I₂Hg(tmtm) is orthorhombic, P2₁2₁2₁, a 12.910(3), b 12.441(3), c 9.863(2) Ǻ, Z4.     The structure of the ligand comprises a pair of planar Me₂NCS₂ fragments linked at the common central sulphur atom with a dihedral of 78.4°. As in the related tetraethylthiuram disulphide, the ?CS₂- geometry is very asymmetric: <C=S> 1.65₇; <C-S> 1.79₃ Ǻ; <S-C-S> 119.3; <S-C-N> 115.2; <S=C-N> 125.4°; with C-S-C, 103.2(2)°. The metal-atom geometry in I₂Hg(tmtm) is pseudo-trigonal prismatic, as in I₂Hg(Me₂NCS₂- S₂CNMe₂), the prism apex being occupied by a ligand sulphur atom, but considerable changes are observed in the geometry about the metal as a consequence of the change in the ligand ?bite?.