Double Pseudopolymeric [Au{S2CN(CH2)5}2]2[Ag2Cl4]·CH2Cl2 Complex: Preparation, Principles of Supramolecular Self-Assembly, Thermal Behavior, and Biological Activity against Mycolicibacterium smegmatis Strain

Abstract

The double Au(III)–Ag(I) complex crystallizing as the solvated form of [Au{S2CN(CH2)5}2]2[Ag2Cl4]· CH2Cl2 (I) was obtained by the reaction of silver(I) N,N-pentamethylenedithiocarbamate with a solution of Na[AuCl4]/5.15 M NaCl. According to X-ray diffraction data (CIF file CCDC no. 2062810), the structural units of the compound are nonequivalent [Au{S2CN(CH2)5}2]+ cations (noncentrosymmetric A and centrosymmetric B and C in a ratio of 2 : 1 : 1), cyclic tetrachlorodiargentate(I) anions, [Ag2Cl4]2–, and solvating CH2Cl2 molecule. The latter is retained in the structure due to two nonequivalent C–H···Cl hydrogen bonds formed with the cyclic [Ag2Cl4]2– anion involving its terminal Cl(1) and bridging Cl(2) chlorine atoms. The supramolecular self-organization of I is based on a system of multiple Ag···S and Cl···S secondary interactions that сombine the ionic structural units of the complex into an intricate two-dimensional pseudopolymer layer. A study of the thermal behavior of I by simultaneous thermal analysis established the conditions for quantitative reduction of bound gold(III) and silver(I). The studied Au(III)–Ag(I) compound exhibits a high level of biological activity against the nonpathogenic M. smegmatis strain.