Investigating the Ground-State Rotamers of n-Propylperoxy Radical
- Univ. of Georgia, Athens, GA (United States). Center for Computational Quantum Chemistry
The n-propylperoxy radical has been described as a molecule of critical importance to studies of low temperature combustion. Ab initio methods were used to study this three-carbon alkylperoxy radical, normal propylperoxy. Reliable CCSD(T)/ANO0 geometries were predicted for the molecule's five rotamers. For each rotamer, energetic predictions were made using basis sets as large as the cc-pV5Z in conjunction with coupled cluster levels of theory up to CCSDT(Q). Along with the extrapolations, corrections for relativistic effects, zero-point vibrational energies, and diagonal Born--Oppenheimer corrections were used to further refine energies. The results indicate that the lowest conformer is the gauche-gauche (GG) rotamer followed by the gauche-trans (0.12 kcal mol^-1 above GG), trans-gauche (0.44 kcal mol^-1), gauche'-gauche (0.47 kcal mol^-1), and trans-trans (0.57 kcal mol^-1). Fundamental vibrational frequencies were obtained using second-order vibrational perturbation theory (VPT2). This is the first time anharmonic frequencies have been computed for this system. The most intense IR features include all but one of the C-H stretches. The O-O fundamental (1063 cm^-1 for the GG structure) also has a significant IR intensity, 19.6 km mol^-1. The anharmonicity effects on the potential energy surface were also used to compute vibrationally averaged r_g,0 K bond lengths, accounting for zero-point vibrations present within the molecule.
- Research Organization:
- Univ. of Georgia, Athens, GA (United States). Center for Computational Quantum Chemistry
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES)
- Grant/Contract Number:
- FG02-97ER14748; DEFG02-97-ER14748
- OSTI ID:
- 1329476
- Alternate ID(s):
- OSTI ID: 1330594
- Journal Information:
- Journal of Chemical Physics, Vol. 145, Issue 17; ISSN 0021-9606
- Publisher:
- American Institute of Physics (AIP)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
tert -Butyl peroxy radical: ground and first excited state energetics and fundamental frequencies
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journal | January 2019 |
The multichannel n -propyl + O 2 reaction surface: Definitive theory on a model hydrocarbon oxidation mechanism
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journal | March 2018 |
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