Structural organization of dithiocarbamate heteropolynuclear gold(III)-cadmium complexes from X-ray crystallography and 113Cd MAS NMR spectroscopy data

Abstract

We study the interaction of dialkyl substituted and cyclic cadmium dithiocarbamates with [AuCl4]− anions in 2M HCl medium. The state of the chemisorbents upon contact with AuCl3 solutions is controlled by 113Cd MAS NMR spectroscopy. The result of the heterogeneous reactions involving chemisorption binding of gold(III) from the solutions and partial ion exchange is the formation of heteropolynuclear gold(III)-cadmium complexes. The crystal and molecular structure of the acetone-solvated form of polymeric bis-(N,N-diethyldithiocarbamato-S,S′) gold(III) hexachlorodicadmate is identified by single-crystal XRD. The main structural moieties of the compound are complex [Au{S2CN(C2H5)2}2]+ cations and [Cd2Cl6]2− anions. The structural self-organization of the complex at the supramolecular level is attributed to the secondary Au…S bonds between neighboring isomeric complex gold(III) cations; the bonding results in the formation of linear polymer ([Au{S2CN(C2H5)2}2]+)n chains, with [Cd2Cl6]2− anions alternating to the right and left of the chains.