A novel silver(I) di-iso-butyldithiocarbamate: Unusually complicated 1-D polymeric structure, multiple ligand-supported Ag–Ag interactions and its capability to bind gold(III). Preparation, structural organisation and (13C, 15N) CP-MAS NMR of [Ag6(S2CNiBu2)6]n and [Au(S2CNiBu2)2][AgCl2

Abstract

We have synthesised three new complexes of [Ag6{S2CN(iso-C4H9)2}6]n (1), [Au{S2CN(iso-C4H9)2}2][AgCl2] (2) and [Au{S2CN(iso-C4H9)2}2][Ag0.69Au0.31Cl2] (3), chemically identified these compounds using solution (1H, 13C) and solid-state (13C, 15N) CP-MAS NMR and FT-IR spectroscopy, and structurally characterised them by single-crystal X-ray diffraction analysis. There are six structurally inequivalent silver(I) centres in the former compound, whose unusually complicated, monodimensional polymeric structure is generally stabilised by six unequal iBuDtc ligands acting as bridges, along with numerous ligand-supported Ag–Ag interactions. Studying the capability of the precipitated AgiBuDtc to bind gold(III) from a [AuCl4]–/5.15 M NaCl solution, the double pseudo-polymeric heterometallic dithiocarbamato-chlorido complexes 2 and 3 were successfully obtained as individual fixation modes of gold to the solid phase. In the self-assembly of a bidimensional supramolecular structure of the latter two compounds, numerous interionic secondary bonds (Au···S, Ag···S and S···Cl), the anagostic HC···Ag interactions and the Cl···HC hydrogen bonds play a key role. To study the thermal behaviour of crystalline compounds 1 and 2, we additionally used simultaneous thermal analysis (STA). During the thermolysis of 1/2, the formation of Ag2S/AgCl,Au0 was supported, respectively, by energy dispersive X-ray (EDX) spectroscopy, while the dispersity and morphology of residual substances were studied using scanning electron microscopy.