A 1:2 complex of mercury(II) chloride with 1,3-imidazole-2-thione

The Hg atom in the title monomeric complex, di­chloro­bis(3-imidazolium-2-thiol­ato-S)­mercury(II), [HgCl₂(C₃H₄N₂S)₂], is four-coordinate having an irregular tetrahedral geometry composed of two Cl atoms [Hg—Cl 2.622 (2) and 2.663 (2) Å] and two thione S atoms [Hg—S 2.445 (2) and 2.462 (2) Å]. The monodentate thione ligand adopts a zwitterionic form and exists as the 3-imidazolium-2-thiol­ate ion. The bond angle S1—Hg—S2 of 130.87 (8)° has the greatest deviation from ideal tetrahedral geometry. Intermolecular hydrogen bonds between two of the four N—H groups and one of the Cl atoms [3.232 (8) and 3.238 (7) Å] stabilize the crystal structure, while the other two N—H groups contribute through the formation of N—H⋯Cl intramolecular hydrogen bonds with the other Cl atom [3.121 (7) and 3.188 (7) Å].