Binding of gold(iii) with silver(i) dipropyldithiocarbamate: supramolecular self-assembly (role of secondary Au…S and Ag…S bonds) and thermal behavior of the ionic-polymer complex ([Au(S2CNPr2)2][AgCl2])n

Abstract

The double ionic-polymer complex ([Au(S₂CNPr₂)₂][AgCl₂])_n (1) was prepared as an individual fixation form of gold(III) from NaCl solutions with silver(I) dipropyldithiocarbamate and was characterized by single-crystal X-ray diffraction and ¹³C magic-angle spinning (MAS) NMR spectroscopy. The structure of 1 comprises two nonequivalent centrosymmetric complex cations [Au(S₂CNPr₂)₂]⁺ (A and B) and the discrete linear anion [AgCl₂]^–. Gold(III) cations are linked by pairs of unsymmetrical secondary Au…S bonds to form linear supramolecular chains (…A…B…)n. Neighboring cations are additionally linked by [AgCl₂]^– anions via secondary Ag…S and Cl…S bonds, the anions being involved in the overall stabilization of the supramolecular structure. The cation–anion interactions lead to a distortion of the linear configuration of the [AgCl₂]^– anion. The character of thermolysis of 1 accompanied by quantitative regeneration of bound Au and Ag was established by simultaneous thermal analysis.