title: Infrared spectra and structures of the neutral and charged CrCO2 and Cr(CO2)2 isomers in solid neon.
abstract: The reactions from codeposition of laser-ablated chromium atoms with carbon dioxide in excess neon are studied by infrared absorption spectroscopy. The species formed are identified by the effects of isotopic substitution on their infrared spectra. Density functional calculations are performed to support the spectral assignments and to interpret the geometric and electronic structures of the experimentally observed species. Besides the previously reported insertion products OCrCO and O2Cr(CO)2, the one-to-one Cr(CO2) complex and the one-to-two Cr(CO2)2 complex as well as the CrOCrCO and OCCrCO3 complexes are also formed. The Cr(CO2) complex is characterized to be side-on η(2)-C,O-coordinated. The Cr(CO2)2 complex is identified to involve a side-on η(2)-C,O-coordinated CO2 and an end-on η(1)-O-coordinated CO2. OCCrCO3 is a carbonate carbonyl complex predicted to have a planar structure with a η(2)-O,O-coordinated carbonate ligand. The CrOCrCO complex is predicted to be linear with a high-spin ground state. Besides the neutral molecules, charged species are also produced. The Cr(CO2)(+) and Cr(CO2)2(+) cation complexes are characterized to have linear end-on η(1)-O-coordinated structures with blue-shifted antisymmetric CO2 stretching vibrational frequencies. The OCrCO(-) anion is bent with the Cr-O and CO stretching frequencies red-shifted from those of OCrCO neutral molecule.
authors.affiliation: Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysts and Innovative Materials, Fudan University , Shanghai 200433, China.
authors.forename: Qingnan
authors.initials: Q
authors.lastname: Zhang
authors.forename: Mohua
authors.initials: M
authors.lastname: Chen
authors.forename: Mingfei
authors.initials: M
authors.lastname: Zhou
mesh_terms: D000838:Anions / Q000737:chemistry; D002245:Carbon Dioxide / Q000737:chemistry; D017608:Chromium Compounds / Q000737:chemistry*; D007536:Isomerism; D009356:Neon / Q000737:chemistry*; D013055:Spectrophotometry, Infrared; D014732:Vibration
chemical_list: D000838:Anions; D017608:Chromium Compounds; D002245:Carbon Dioxide; D009356:Neon