First heterobimetallic Ag I -Co III coordination compound with both bridging and terminal -NO 2 coordination modes: synthesis, characterization, structural and computational studies of (PPh 3 ) 2 Ag I -(μ-κ 2 O,O':κN-NO 2 )-Co III (DMGH) 2 (κN-NO 2 ).

An unusual heterobimetallic bis(triphenylphosphane)(NO2 )AgI -CoIII (dimethylglyoximate)(NO2 ) coordination compound with both bridging and terminal -NO2 (nitro) coordination modes has been isolated and characterized from the reaction of [CoCl(DMGH)2 (PPh3 )] (DMGH2 is dimethylglyoxime or N,N'-dihydroxybutane-2,3-diimine) with excess AgNO2 . In the title compound, namely bis(dimethylglyoximato-1κ2 O,O')(μ-nitro-1κN:2κ2 O,O')(nitro-1κN)bis(triphenylphosphane-2κP)cobalt(III)silver(I), [AgCo(C4 H7 N2 O2 )2 (NO2 )2 (C18 H15 P)2 ], one of the ambidentate -NO2 ligands, in a bridging mode, chelates the AgI atom in an isobidentate κ2 O,O'-manner and its N atom is coordinated to the CoIII atom. The other -NO2 ligand is terminally κN-coordinated to the CoIII atom. The structure has been fully characterized by X-ray crystallography and spectroscopic methods. Density functional theory (DFT) and time-dependent density functional theory (TD-DFT) have been used to study the ground-state electronic structure and elucidate the origin of the electronic transitions, respectively.