Frontiers in the organometallic chemistry of silver: Accessing new structures and reactivity through sterically demanding, electron-rich N-heterocyclic carbene ligands

The synthesis and characterization of novel complexes of silver supported by sterically demanding, highly electrophilic N-heterocyclic carbene (NHC) ancillary ligands, is described. Stable hydride, fluoride, alkoxide, alkyl, aryl, and alkynyl complexes are characterized by NMR spectroscopy and X-ray diffraction crystallography, and their reactivity is investigated. The interaction of silver centers in dinuclear complexes is probed by 109Ag NMR spectroscopy. Relevance to renewable fuel technology is demonstrated through the mediation of fundamental chemical transformations, including the heterolysis of hydrogen, the transfer of hydride to carbon dioxide, and the formation of carbon-carbon bonds. Kinetic studies shed light on the mechanism of hydrogen activation by hard-soft mismatched complexes of silver, and a formal catalytic cycle for the hydrogenation of carbon dioxide to formate derivatives is reported.Ph.D