title: Infrared Spectroscopy of Gas-Phase M+(CO2)n(M = Co, Rh, Ir) Ion-Molecule Complexes.
abstract: The structures of gas-phase M+(CO2)n(M = Co, Rh, Ir; n = 2-15) ion-molecule complexes have been investigated using a combination of infrared resonance-enhanced photodissociation (IR-REPD) spectroscopy and density functional theory. The results provide insight into fundamental metal ion-CO2interactions, highlighting the trends with increasing ligand number and with different group 9 ions. Spectra have been recorded in the region of the CO2asymmetric stretch around 2350 cm-1using the inert messenger technique and their interpretation has been aided by comparison with simulated infrared spectra of calculated low-energy isomeric structures. All vibrational bands in the smaller complexes are blue-shifted relative to the asymmetric stretch in free CO2, consistent with direct binding to the metal center dominated by charge-quadrupole interactions. For all three metal ions, a core [M+(CO2)2] structure is identified to which subsequent ligands are less strongly bound. No evidence is observed in this size regime for complete activation or insertion reactions.
authors.affiliation: Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford , South Parks Road, Oxford OX1 3QZ, United Kingdom.
authors.forename: Andreas
authors.initials: A
authors.lastname: Iskra
authors.affiliation: Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford , South Parks Road, Oxford OX1 3QZ, United Kingdom.
authors.forename: Alexander S
authors.initials: AS
authors.lastname: Gentleman
authors.affiliation: Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford , South Parks Road, Oxford OX1 3QZ, United Kingdom.|Chemistry Department, Catalysis Research Center, Technical University of Munich , Lichtenbergstraße 4, 85748 Garching, Germany.
authors.forename: Aras
authors.initials: A
authors.lastname: Kartouzian
authors.affiliation: Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford , South Parks Road, Oxford OX1 3QZ, United Kingdom.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Kent
authors.affiliation: Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford , South Parks Road, Oxford OX1 3QZ, United Kingdom.
authors.forename: Alastair P
authors.initials: AP
authors.lastname: Sharp
authors.affiliation: Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford , South Parks Road, Oxford OX1 3QZ, United Kingdom.
authors.forename: Stuart R
authors.identifier: http://orcid.org/0000-0002-3166-8631
authors.initials: SR
authors.lastname: Mackenzie