Synthesis, crystal structure and DFT calculations of bis(1,3-diazinane-2-thione-κS)dicyanido disilver(I), [{Ag(Diaz)2}{Ag(CN)2}]

A silver(I) complex containing cyanide and diazinane-2-thione (Diaz) ligands, [Ag(Diaz)2Ag(CN)2] (1) was prepared and its crystal structure was determined. The compound crystallizes in the orthorhombic space group, Pnma. The structure of the complex consists of [Ag(Diaz)2]+ cationic and [Ag(CN)2]− anionic units, which are associated through AgNC and argentophilic interactions to form a two dimensional polymeric network. An upfield shift in the CS resonance of Diaz in 13C NMR and downfield shift in NH resonance in 1H NMR are consistent with sulfur coordination to silver(I). The appearance of a band around 2100 cm−1 in IR and a resonance at 143 ppm in 13C NMR indicates the binding of cyanide to silver(I). DFT calculations on model head-to-tail dimeric systems mimic the bridging behavior of the [Ag(CN)2]− anionic units that connect the metal center of the cationic unit by N→Ag coordination in one N terminus, whereas the other terminal N atom is involved in hydrogen bonding towards Diaz H atoms.

Graphical abstract[Ag(Diaz)2Ag(CN)2] (Diaz = diazinane-2-thione) was prepared and characterized both experimentally and theoretically. It consists of cationic [Ag(Diaz)2]+ and anionic [Ag(CN)2]− units, associated through argentophilic and non-covalent interactions to form a two dimensional polymeric network.Figure optionsDownload full-size imageDownload as PowerPoint slide