Time-dependent density functional theory assessment of UV absorption of benzoic acid derivatives
Journal Article
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· Journal of Physical Chemistry. A, Molecules, Spectroscopy, Kinetics, Environment, and General Theory
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Tennessee, Knoxville, TN (United States)
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Benzoic acid (BA) derivatives of environmental relevance exhibit various photophysical and photochemical characteristics. Here, time-dependent density functional theory (TDDFT) is used to calculate photoexcitations of eight selected BAs and the results are compared with UV spectra determined experimentally. High-level gas-phase EOM-CCSD calculations and experimental aqueous-phase spectra were used as the references for the gas-phase and aqueous-phase TDDFT results, respectively. A cluster-continuum model was used in the aqueous-phase calculations. Among the 15 exchange correlation (XC) functionals assessed, five functionals, including the meta-GGA hybrid M06-2X, double hybrid B2PLYPD, and range-separated functionals CAM-B3LYP, ωB97XD, and LC- ωPBE, were found to be in excellent agreement with the EOM-CCSD gas-phase calculations. These functionals furnished excitation energies consistent with the pH dependence of the experimental spectra with a standard deviation (STDEV) of 0.20 eV. A molecular orbital analysis revealed a πσ* feature of the low-lying transitions of the BAs. Furthermore, the CAM-B3LYP functional showed the best overall performance and therefore shows promise for TDDFT calculations of processes involving photoexcitations of benzoic acid derivatives.
- Research Organization:
- Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
- Sponsoring Organization:
- ORNL Program Development; USDOE
- DOE Contract Number:
- AC05-00OR22725
- OSTI ID:
- 1265968
- Journal Information:
- Journal of Physical Chemistry. A, Molecules, Spectroscopy, Kinetics, Environment, and General Theory, Journal Name: Journal of Physical Chemistry. A, Molecules, Spectroscopy, Kinetics, Environment, and General Theory Journal Issue: 48 Vol. 116; ISSN 1089-5639
- Publisher:
- American Chemical Society
- Country of Publication:
- United States
- Language:
- English