|
1
|
Koncz B, Bazsó G, Reza MA, Telfah H, Hegedüs K, Liu J, Tarczay G. Revealing Long-Range Substituent Effects in the Laser-Induced Fluorescence and Dispersed Fluorescence Spectra of Jet-Cooled CH xF 3-xCH 2O ( x = 1, 2, 3) Radicals. J Phys Chem A 2019; 123:10947-10960. [PMID: 31790245 DOI: 10.1021/acs.jpca.9b09829] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The B̃-X̃ laser-induced fluorescence (LIF) and dispersed fluorescence (DF) spectra of the atmospherically important β-monofluoro ethoxy (MFEO), β,β-difluoro ethoxy (DFEO), and β,β,β-trifluoro ethoxy (TFEO) radicals were recorded with vibronic resolution under jet-cooled conditions. To simulate the spectra, Franck-Condon factors were obtained from quantum chemical computations carried out at the CAM-B3LYP/6-311++G(d,p) level of theory. The simulations reproduce well both the LIF and DF spectra. Both conformers (G and T) of MFEO and one (G) of the two conformers of DFEO contribute to the LIF spectrum. A comparison between the experimental and calculated spectra confirms the expected long-range field effects of the CHxF3-x group on electronic transition energies and bond strengths, especially in the excited electronic (B̃) state. Although TFEO has only one conformer, its LIF spectrum is highly congested, which is attributed to the interaction between CO stretch and the -CF3 internal rotation.
Collapse
Affiliation(s)
- Benedek Koncz
- ELTE Eötvös University , Institute of Chemistry, Laboratory of Molecular Spectroscopy , PO Box 32, H-1518 Budapest 112 , Hungary
| | - Gábor Bazsó
- ELTE Eötvös University , Institute of Chemistry, Laboratory of Molecular Spectroscopy , PO Box 32, H-1518 Budapest 112 , Hungary
| | - Md Asmaul Reza
- Department of Chemistry , University of Louisville , 2320 South Brook Street , Louisville , Kentucky 40292 , United States
| | - Hamzeh Telfah
- Department of Chemistry , University of Louisville , 2320 South Brook Street , Louisville , Kentucky 40292 , United States
| | - Kristóf Hegedüs
- Research Centre for Natural Sciences , Institute of Organic Chemistry , PO Box 286, H-1519 Budapest , Hungary
| | - Jinjun Liu
- Department of Chemistry , University of Louisville , 2320 South Brook Street , Louisville , Kentucky 40292 , United States.,Conn Center for Renewable Energy Research , University of Louisville , 2320 South Brook Street , Louisville , Kentucky 40292 , United States
| | - György Tarczay
- ELTE Eötvös University , Institute of Chemistry, Laboratory of Molecular Spectroscopy , PO Box 32, H-1518 Budapest 112 , Hungary.,MTA-ELTE Lendület Laboratory Astrochemistry Research Group , PO Box 32, H-1518 Budapest 112 , Hungary
| |
Collapse
|