Silver(I) and Gold(I) Monothiocarbonate Complexes: Synthesis, Structure, Luminescence

The monothiocarbonate ligand, [S(O)COR](-), is unusual and rare regarding its use in the formation of coordination compounds. Here, we report the synthesis and structures of the silver(I) and gold(I) monothiocarbonate complexes, [{Ag-4(SC(O)(OPr)-Pr-i)(2)(2,2 '-bpy)(4)}(PF6)(2)](n) (1) and [Au-2{S(O)(COPr)-Pr-i}(2)(dppe)](n) (2), respectively. Both complexes are coordination polymers, with 1 being cationic and 2 neutral. The uniqueness of the ligand is that it is monoanionic and contains both a 'hard' O-donor ligand and a 'soft' S-donor ligand in a O-C-S manifold with, in principle, electron delocalization across the three atoms. However, for both complexes 1 and 2, it was found that the binding occurred exclusively through the S-donor atom, while the C=O portion remained dangling and was not involved in bonding. This bonding mode departs significantly from the symmetrical S-C-S type ligand such as dithiocarbamates. The structures were analysed and confirmed by NMR and X-ray crystallography.

Automated summary

The monothiocarbonate ligand is rare in its use in the formation of coordination compounds. In this study, silver(I) and gold(I) monothiocarbonate complexes were synthesized and analyzed using NMR and X-ray crystallography. The bonding mode of these complexes was found to be different from symmetrical S-C-S type ligands, with the binding occurring exclusively through the S-donor atom.