Chemisorptive Synthesis, Self-Assembly of Complicated 2D and 3D Supramolecular Architectures (Role of Hydrogen Bonds and Secondary Interactions Au···S and S···Cl), and Thermal Behavior of Pseudo-Polymeric Gold(III)–Mercury(II) Dibutyldithiocarbamato-Chlorido Complexes

Abstract

The interaction of mercury(II) dibutyl dithiocarbamate (BuDtc) with [AuCl4]− anions in 2 M HCl was studied. The heterogeneous reaction of chemisorption binding of gold(III) from the solution leads to heteronuclear Au(III)–Hg(II) pseudo-polymeric complexes of the ionic type: ([Au{S2CN(C4H9)2}2]2[Hg2Cl6])n (I) and ([(C4H9)2NH2]0.5[Au{S2CN(C4H9)2}2]1.5[Hg2Cl6])n (II), whose crystal and supramolecular structures were determined by X-ray diffraction analysis (CIF files CCDC nos. 1965151 (I) and 1965152 (II)). The cationic part of each compound is represented by two structurally nonequivalent complex ions [Au{S2CN(C4H9)2}2]+ (A and B) being conformers. The structure of compound II additionally contains the dibutylammonium cation. In both cases, binuclear [Hg2Cl6]2– is a counterion (centrosymmetric in the structure of compound I and noncentrosymmetric in the structure of compound II). Owing to the secondary interactions Au···S and S···Cl (as well as hydrogen bonds N–H···Cl in compound II), all ionic structural units participate in the construction of pseudo-polymeric cationic and cation-anionic chains, which are combined into a complicatedly organized 2D supramolecular network (in I) or 3D framework (in II). The thermal behavior of compounds I and II was studied by simultaneous thermal analysis. The thermolysis of the complexes is accompanied by the quantitative regeneration of bound gold, liberation of HgCl2, and partial transformation of the latter into HgS.