A homoleptic Ag complex stabilized by succinimidate ligands.

Herein, the first example of a homoleptic Ag complex stabilized by a monodentate N-donor ligand is presented. Na[SO] oxidizes the linear Ag complex, Na[Ag(succ)] (1), to form a square planar argentate(iii) ion, [Ag(succ)], which crystallizes with a polymeric chain-structure, M[Ag(succ)] (2), when treated with alkali metal sulfate MSO (M = K, Rb, Cs). A mixed-valent Robin-Day class I system, [(HO)Ag][Ag(succ)] (2), forms in the absence of K/Rb/Cs ion. Diamagnetic 2 displays a succinimide C[double bond, length as m-dash]O stretching frequency at higher energy than does the isoelectronic Pd complex, [(HO)Na][Pd(succ)] (3). Moreover, 2 displays UV-vis absorptions that are more intense and occur at lower energy than those in 3. The electron-deficient nature of 2 is further evident from its ability to oxidize water to O. From Ag magic-angle spinning NMR studies, a highly deshielded Ag environment in 2 (2080 ppm) relative to the Ag starting material 1 (492 ppm) is observed.