On the Hydrogen Oxalate Binding Motifs onto Dinuclear Cu and Ag Metal Phosphine Complexes.

We report the binding geometries of the isomers that are formed when the hydrogen oxalate ((CO ) H=HOx) anion attaches to dinuclear coinage metal phosphine complexes of the form [M M dcpm (HOx)] with M=Cu, Ag and dcpm=bis(dicyclohexylphosphino)methane, abbreviated [MM] . These structures are established by comparison of isomer-selective experimental vibrational band patterns displayed by the cryogenically cooled and N -tagged cations with DFT calculations of the predicted spectra for various local minima. Two isomeric classes are identified that feature either attachment of the carboxylate oxygen atoms to the two metal centers (end-on docking) or attachment of oxygen atoms on different carbon atoms asymmetrically to the metal ions (side-on docking).

Photoinitiated Charge Transfer in a Triangular Silver(I) Hydride Complex and Its Oxophilicity.

The photoexcitation of a triangular silver(I) hydride complex, [Ag (μ -H)(μ -dcpm) ](PF ) ([P](PF ) , dcpm=bis(dicyclohexylphosphino)methane), designed with "UV-silent" bis-phosphine ligands, provokes hydride-to-Ag single and double electron transfer. The nature of the electronic transitions has been authenticated by absorption and photodissociation spectroscopy in parallel with high-level quantum-chemical computations utilizing the GW method and Bethe-Salpeter equation (GW-BSE). Specific photofragments of mass-selected [P] ions testify to charge transfer and competing pathways resulting from the unique [Ag (μ -H)] scaffold.

Gas-Phase Photoluminescence and Photodissociation of Silver-Capped Hexagold Clusters.

We report on the radiative and nonradiative deactivation pathways of selected charge states of the stoichiometric hexagold phosphine-stabilized ionic clusters, [(C)(AuDppy)Ag·(BF) ] with x = 2 and 3 (Dppy = diphenylphosphino-2-pyridine), combining gas-phase photoluminescence and photodissociation with quantum chemical computations. These clusters possess an identical isostructural core made of a hyper-coordinated carbon at their center octahedrally surrounded by six gold ions, and two silver ions at their apexes. Their luminescence and fragmentation behavior upon photoexcitation was investigated under mass and charge control in an ion trap.

Bimetallic d -Metal Complexes of a Bipyridine Substituted N-Heterocyclic Carbene.

The hybrid ligand 3-(2,2'-bipyridine-6-ylmethyl)-1-mesityl-1H-imidazolylidene (NHC ) featuring both carbene and N-donor sites, was selectively complexed with various d metal cations in order to examine its coordination behavior with regard to homo and heterometallic structures. Respective silver complexes can be obtained by the silver oxide route and are suitable transmetallation reagents for the synthesis of gold(I) compounds. Starting from the mononuclear complexes [(NHC )AuCl], [(NHC )Au(C F )] and [(NHC ) Au][ClO ], open-chain as well as cyclic heterobimetallic complexes containing Cu , Ag , Zn , Cd , and Hg were synthesized.

Vibrational Coherence Controls Molecular Fragmentation: Ultrafast Photodynamics of the [AgCl] Scaffold.

The recently introduced pump-probe fragmentation action spectroscopy reveals a unique observation of excited state vibrational coherence (430-460 fs) in the isolated metal complex [Ag(Cl)(dcpm))] (dcpm = bis(dicyclohexylphosphino)methane) containing the [AgCl] scaffold. After photoexcitation by an XMCT transition (260 nm) in an ion trap, an unexpected correlation between specific fragment ions (loss of HCl/Cl vs loss of dcpm) and the phase of the wave packet is probed (1150 nm). Based on ab initio calculations, we assign the primary electronically excited state and ascribe the observed coherences (72-78 cm) to contain predominantly Ag-Ag stretch character.