Carbon trioxide explained

Carbon trioxide (CO₃) is an unstable oxide of carbon (an oxocarbon). The possible isomers of carbon trioxide include ones with molecular symmetry point groups C_s, D_3h, and C_2v. The C_2v state, consisting of a dioxirane, has been shown to be the ground state of the molecule.^[1] Carbon trioxide should not be confused with the stable carbonate ion .

Carbon trioxide can be produced, for example, in the drift zone of a negative corona discharge by reactions between carbon dioxide (CO₂) and the atomic oxygen (O) created from molecular oxygen by free electrons in the plasma.^[2] Another reported method is photolysis of ozone O₃ dissolved in liquid CO₂, or in CO₂/SF₆ mixtures at −45 °C, irradiated with light of 253.7 nm. The formation of CO₃ is inferred but it appears to decay spontaneously by the route

2 CO₃ → 2 CO₂ + O₂with a lifetime much shorter than 1 minute.^[3] Carbon trioxide can be made by blowing ozone at dry ice (solid CO₂), and it has also been detected in reactions between carbon monoxide (CO) and molecular oxygen (O₂). Along with the ground state C_2v isomer,^[4] the first spectroscopic detection of the D_3h isomer was in electron-irradiated ices of carbon dioxide.^[5]

Further reading

• Sobek V. . Skalný J. D. . A simple model of processes in the drift region of negative corona discharge in a mixture of air with halocarbons . Czechoslovak Journal of Physics . 43 . 8 . 807 . 1993 . 10.1007/BF01589802 . 1993CzJPh..43..807S . 120356317 .
• Pople J. A. . Seeger U. . Seeger R. . Paul von Rague Schleyer . Schleyer P. v. R. . The structure of carbonate . Journal of Computational Chemistry . 1 . 2 . 199–203 . 2004 . 10.1002/jcc.540010215 . 98748631 . John Pople .
• Carbonate: Its Production, Infrared Spectrum, and Structure Studied in a Matrix of Solid CO₂ . The Journal of Chemical Physics . 1966 . 45 . 12 . 4469–4481 . 10.1063/1.1727526 . Moll N. G. . Clutter D. R. . Thompson W. E. . 1966JChPh..45.4469M.
• The Journal of Chemical Physics . 1968 . 49 . 9 . 4043–4047 . Geometry and Electronic Structure of Carbon Trioxide . 10.1063/1.1670715 . Gimarc B. M. . Chou T. S. . 1968JChPh..49.4043G .
• Pressure dependence of carbon trioxide formation in the gas-phase reaction of O(1D) with carbon dioxide . DeMore W. B. . Dede C. . 2621–2625 . 10.1021/j100707a006 . 1970 . 74 . 13 . Journal of Physical Chemistry.
• Chemical Physics . 95 . 3 . 1985 . 10.1016/0301-0104(85)80160-9 . A theoretical study of the force field for carbon trioxide . Francisco J. S. . Williams I. H. . 373. 1985CP.....95..373F .

Notes and References

1. T. Kowalczyk . A. I. Krylov . Aug 2007 . Electronic structure of carbon trioxide and vibronic interactions involving Jahn–Teller states . J. Phys. Chem. A . 111 . 8271–8276 . 10.1021/jp073627d . 17661455 . 33 . 1089-5639. 2007JPCA..111.8271K .
2. A theoretical study of the structure and properties of carbon trioxide . Chemical Physics Letters . 11 . 5 . 593–597 . 1971CPL....11..593S . 10.1016/0009-2614(71)87010-0 . 1971 . Sabin, J. R . Kim, H.
3. Formation of carbon trioxide in the photolysis of ozone in liquid carbon dioxide . DeMore W. B. . Jacobsen C. W. . 2935–2938 . 10.1021/j100843a026 . 1969 . 73 . 9 . Journal of Physical Chemistry.
4. 10.1039/b315626p. Untangling the formation of the cyclic carbon trioxide isomer in low temperature carbon dioxide ices. Physical Chemistry Chemical Physics. 6. 4. 735. 2004. Bennett. Chris J.. Jamieson. C.. Mebel. Alexander M.. Kaiser. Ralf I.. 51769127. 2004PCCP....6..735B.
5. 10.1002/cphc.200600390. 17029325. Identification of the D_3h Isomer of Carbon Trioxide (CO₃) and Its Implications for Atmospheric Chemistry. ChemPhysChem. 7. 12. 2508–2513. 2006. Jamieson. Corey S.. Mebel. Alexander M.. Kaiser. Ralf I..