Dinuclear gold(I) and gold(III) complexes involving di(N-heterocyclic carbene) ligands – Synthesis, characterization and DFT studies

Some new dinuclear gold(I) and gold(III) complexes containing di(NHC) ligands have been synthesized and characterized. The dinuclear centers were coordinated by methylene, ethylene or propylene bridged di(NHC) ligands bearing alcohol functionalized side arms. The oxidation of the gold(I) to gold(III) have been carried out using bromine. X-ray structure analyses of two dinuclear gold(I) and three dinuclear gold(III) complexes show the solid state structures of these compounds. Thermodynamic aspects of the oxidative additions of bromine to the gold(I) species leading to gold(III) compounds passing by unstable gold(II) intermediates have been studied by DFT calculations.