Platform Design Enabling Silver(III) Stabilization ─ The Uprise of Ag^IIICF₃ Chemistry?

Unlike its coinage metal counterparts, copper and gold, silver chemistry remains poorly developed and mostly restricted to the oxidation state +I, which embraces a large variety of coordination environments and types of ligand. Higher oxidation states, that is, +II and +III, are significantly less represented and predominantly adopt a square planar (SP-4) geometry around the metal center. In particular, well-defined d⁸ Ag^III compounds are scarce, and include only a handful of examples exhibiting out-of-plane silver coordination. This Concept Article summarizes the strategies known to stabilize Ag^III, as well as the unusual electronic structures (inverted ligand field) often found in these compounds. The intriguing case study of the expansion in the coordination number in Ag^IIICF₃ compounds will be highlighted.