Isolation of a Silver(0) Dimer with a Direct Ag–Ag Bond

Despite decades of efforts, molecule featuring a direct Ag(0)–Ag(0) bond has never been isolated─a fundamental challenge that stands in contrast to the established chemistry of gold. Here we report the synthesis, characterization, and reactivity of the first molecular Ag(0)–Ag(0) bonded complex, which was stabilized by a tridentate P–Mg–P pincer ligand. Computational studies indicate that the Ag(0)–Ag(0) σ-bond acts as a two-electron donor to the Mg centers. This Ag(0)2 complex reacts with a range of substrates─including selenium, diphenyl diselenide, azobenzene, phenylacetylene, and an isocyanide─to afford a series of heterometallic Mg/Ag products through two-electron reduction processes. These transformations highlight the reducing character of the Ag(0)2 unit and help fill a gap in the periodic trend of coinage-metal chemistry.