Iodido{4-phenyl-1-[1-(1,3-thia-zol-2-yl-κN)ethyl-idene]thio-semicarbazidato-κN',S}{4-phenyl-1-[1-(1,3-thia-zol-2-yl)ethyl-idene]thio-semicarbazide-κS}mercury(II).

In the title compound, [Hg(C(12)H(11)N(4)S(2))I(C(12)H(12)N(4)S(2))], the Hg atom is in a distorted square-pyramidal coordination, defined by the iodide ligand, by the S atom of the neutral ligand in the apical position, and by the N atom of the thia-zole ring, the thio-ureido N and the S atom of the deprotonated ligand. The deprotonated ligand intra-molecularly hydrogen bonds to the thia-zole ring N atom, while the deprotonated ligand forms an inter-molecular hydrogen bond to the thiol-ate S atom. The deprotonation of the tridentate ligand and its coordination to Hg via the S atom strikingly affects the C-S bond lengths. In the free ligand, the C-S bond distance is 1.685 (7) Å, whereas it is 1.749 (7) Å in the deprotonated ligand. Similarly, the Hg-S bond distance is slightly longer to the neutral ligand [2.6682 (18) Å] than to the deprotonated ligand [2.5202 (19) Å]. The Hg-I distance is 2.7505 (8) Å.