An ab initio and experimental study of vibrational effects in low energy O++C2H2 charge-transfer collisions
| Autor: | Albert A. Viggiano, Kaori Fukuzawa, Anthony Midey, Edmond Murad, Rainer A. Dressler, Skip Williams, Toshio Matsushita, Yu Hui Chiu, Keiji Morokuma, D. J. Levandier |
|---|---|
| Rok vydání: | 2001 |
| Předmět: | |
| Zdroj: | The Journal of Chemical Physics. 115:3184-3194 |
| ISSN: | 1089-7690 0021-9606 |
| DOI: | 10.1063/1.1385793 |
| Popis: | Theoretical and experimental studies are performed to elucidate the low energy charge-transfer dynamics of the reaction, O+(4S)+C2H2(X 1Σg+)→O+C2H2+. In particular, the role of the low-frequency acetylene bending modes (612 and 730 cm−1) in promoting charge transfer was examined. High-temperature guided-ion beam measurements are carried out over the energy range from near-thermal to 3 eV at 310 and 610 K. The charge-transfer cross sections are found to decrease up to 0.5 eV, to have a constant value at intermediate energies between 0.5 and 1.5 eV, and then to dramatically increase above a threshold of a spin-allowed process determined to be at 1.7 eV. A bending vibrational enhancement of ∼8 is observed at intermediate energies. Thermal energy rate co-efficients are measured in a variable temperature-selected ion flow drift tube apparatus from 193 to 500 K. At each temperature, a negative energy dependence is observed. In order to elucidate the reaction mechanism in detail, high level ab initio calculation... |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|