Time-dependent density functional theory (TD-DFT) calculations of the transition energies and oscillator strengths of fluorinated alkanes have been performed. The TD-DFT method with the non-local B3LYP potential yields transition energies for the methanes, which are smaller by about 10% as compared to the experimental values. An empirical linear correlation was found between the calculated and experimental transition energies both at the B3LYP/DZ+Ryd(C, F) and B3LYP/cc-pVTZ+Ryd(C, F, H) levels for a total of 19 transitions of the fluorinated methanes with linear correlation coefficients of 0.987 for the former and 0.988 for the latter. This empirical correlation for fluorinated methane molecules is found to agree well with the previously obtained empirical correlations between calculated and experimental values for non-fluorinated molecules. The results show that a single empirical-correlation relationship can be used for both non-fluorinated and fluorinated molecules to predict transition energies. This linear relationship is then used to predict the photoabsorption spectra of ethane, propane, butane, and partially and fully fluorinated derivatives. A key result of these calculations is the dominance of Rydberg transitions in the spectral region of interest.
|Number of pages||9|
|Journal||Journal of Fluorine Chemistry|
|State||Published - Jul 1 2003|
Bibliographical noteFunding Information:
This research was performed in part under the management of the Association of Super-Advanced Electronics Technologies (ASET) as part of the Ministry of International Trade and Industry (MITI), Program of Super-Advanced Electronics Technologies supported by the New Energy and Industrial Technology Development Organization (NEDO). This research was supported in part by the U S Department of Energy (Office of Biological and Environmental Research, Office of Science) under Contract DE-AC06-76RLO 1830. Financial support for part of this project from International Sematech is gratefully acknowledged. This research was performed in part in the William R. Wiley Environmental Molecular Sciences Laboratory at the Pacific Northwest National Laboratory. The MSCF is funded by the Office of Biological and Environmental Research in the US Department of Energy. The Pacific Northwest National Laboratory is operated by Battelle Memorial Institute. Part of the calculations in this article were performed on the Joint Research Center for Atom Technology (JRCAT) supercomputer system, which is also supported by NEDO. The authors would like to thank Mr. H. Setoya (ASET), Dr. S. Okazaki (ASET), Prof. K. Tanaka (JRCAT and National Institute for Advanced Interdisciplinary Research (NAIR)) and Prof. C.G. Willson (University of Texas, Austin) for useful discussions.
- Density functional theory
- Fluorinated alkanes
- Photoabsorption spectra
- Rydberg transitions
ASJC Scopus subject areas
- Environmental Chemistry
- Physical and Theoretical Chemistry
- Organic Chemistry
- Inorganic Chemistry