The infrared spectrum of Au-CO2 -: art. no. 154301

The Au-2(-CO) (ion-molecule complex has been studied by gas phase infrared photodissociation spectroscopy. Several sharp transitions can be identified as combination bands involving the asymmetric stretch vibrational mode of the CO)(2) (ligand. Their frequencies are redshifted by several hundred cm-1 from the frequencies of free CO)(- We discuss our findings in the framework of ab initio and density-functional theory calculations, using anharmonic corrections to predict vibrational transition energies. The infrared spectrum is consistent with the formation of an aurylcarboxylate anion with a strongly bent CO)(2)(2) subunit. 2005 American Institute of Physics.