The tetranuclear macrocyclic mercury(II) complex of [Hg<sub>4</sub>{S<sub>2</sub>CN(CH<sub>3</sub>)<sub>2</sub>}<sub>4&l

The tetranuclear mercury(II) dithiocarbamato-chlorido complex [Hg4(S2CNMe2)4Cl4] (I), the molecule of which includes a centrosymmetric 16-membered metallacycle [Hg4S8C4], was prepared by the reaction of solutions of HgCl2 and sodium dimethyldithiocarbamate (Me2Dtc). The crystal, molecular, and supramolecular structures of I were established by direct single crystal X-ray diffraction (CCDC no. 2364847). In complex I, the non-equivalent μ2-bridging dithiocarbamate ligands join neighboring mercury atoms in pairs, thus forming a tetranuclear macrocyclic molecule. The intramolecular Hg···S and Hg···Cl secondary bonds stabilize the spatial configuration of this macrometallacycle. The supramolecular self-organization of the complex is due to the relatively weak, pairwise S···Cl and Hg···Cl secondary interactions, which combine the tetranuclear molecules of I into 2D pseudo-polymer layers; numerous non-classical C–H···Cl and C–H···S hydrogen bonds connect these layers to form a 3D framework. According to simultaneous thermal analysis data, the thermal decomposition of I is accompanied by the formation of HgS and release of HgCl2.