Untangling the formation of the cyclic carbon trioxide isomer in low temperature carbon dioxide ices
作者:Chris J. Bennett、C. Jamieson、Alexander M. Mebel、Ralf I. Kaiser
DOI:10.1039/b315626p
日期:——
mol−1 and the reaction of O(3P) with carbon dioxide to form the carbon trioxide molecule via triplet-singlet intersystem crossing is endoergic by 2 kJ mol−1, the oxygen reactant(s) must have excess kinetic energy (suprathermal oxygen atoms which are not in thermal equilibrium with the surrounding 10 K matrix). A second reaction pathway of the oxygen atoms involves the formation of ozone via molecular
Reactions of<sup>1</sup><i>D</i>Oxygen Atoms in the Photolysis of Carbon Dioxide. II
作者:Peter Warneck
DOI:10.1063/1.1725745
日期:1964.12
The vacuum-uv photolysis of CO2 containing initially no oxygen was investigated in a closed system and the quantum yields of ozone and oxygen determined. The quantum yield for ozone production was found to be below Q(O3) ≤0.03, which is insufficient to explain the oxygen deficiency observed in the O2 quantum yields. The [O2]/[CO] ratio was found to depend on the light intensity, on the time interval after which an irradiated sample was subjected to analysis, and on the ratio of carbon dioxide to admixed rare gas concentration. The results concerning the [O2]/[CO] ratio can be explained by the formation of CO3 due to the attachment of 1D oxygen atoms to CO2. This reaction is in competition with the third-body recombination of 1D oxygen atoms.
Some Photochemical Reactions of O<sub>3</sub>in the Gas Phase
作者:D. Katakis、H. Taube
DOI:10.1063/1.1732521
日期:1962.1.15
When a gaseous mixture containing O3 and CO2 of different isotopic composition is illuminated by uv light, the oxygen that is formed has undergone some exchange with CO2. The extent of this exchange has been studied as a function of initial O3 and CO2 pressure, and the influence of foreign gases on it was also studied. It is concluded that O1D is the intermediate which undergoes rapid exchange with CO2, and further that the reaction O1D+CO2⇌CO+O2does not provide the dominant mechanism for this exchange. The results suggest that at low total pressures exchange takes place by O*+CO2⇌O+CO2*and that at high total pressures, CO3 is formed as an intermediate.
Carbon Trioxide: Its Production, Infrared Spectrum, and Structure Studied in a Matrix of Solid CO<sub>2</sub>
作者:Norman G. Moll、Dale R. Clutter、Warren E. Thompson
DOI:10.1063/1.1727526
日期:1966.12.15
Reactions of oxygen atoms with CO2 molecules to give a species identified as CO3 have been observed in three systems: (1) the photolysis of solid CO2 at 77°K with vacuum-ultraviolet light from a xenon resonance lamp; (2) the photolysis of O3 in a CO2 matrix at 50°—60°K with 2537-Å light from a mercury arc; and (3) the radio-frequency discharge of CO2 gas followed by trapping of products at 50°—70°K. The infrared spectrum of the species includes absorptions at 568, 593, 972, 1073, 1880, 2045, 3105, and 3922 cm−1. Isotopic studies using CO2 enriched with 18O or 13C show that the molecular formula is CO3 and provide a basis for determining the molecular structure. Frequency assignments and isotopic product-rule calculations favor a planar C2v molecule in which the carbon atom is bonded to the unique oxygen atom by a strong carbonyl bond and to two equivalent oxygen atoms by weaker bonds. There is presumably covalent bonding between the two equivalent oxygen atoms. In the proposed frequency assignment it is assumed that the absorption arising from the out-of-plane bending mode is unobserved. Results of photolyzing isotopically nonequilibrated 18O-enriched CO2 indicate that a D3h or C3v species with three equivalent oxygen atoms is involved in the reaction mechanism or is a readily accessible excited state. There is evidence that the observed photodecomposition of CO3 by visible and ultraviolet light yields oxygen atoms and CO2.