TY - JOUR
T1 - Theoretical investigations of the excited-state intramolecular proton transfer reaction in N-substituted-3-hydroxypyridinones
AU - Sobolewski, Andrzej L.
AU - Adamowicz, Ludwik
N1 - Funding Information:
We thank Professor W. Domcke for valuable comments. This study was supported by the National Sci- ence Foundation under Grant No. CHE-9300497 and by grant from the Office of Health and Environmental Research of the Department of Energy (No. DEFG 0393ER61605).
PY - 1995/4/1
Y1 - 1995/4/1
N2 - The potential energy functions of the electronic ground state, as well as the lowest nπ* and ππ* excited singlet states of 3-hydroxy-4-pyridinone and 3-hydroxy-2-methyl-4-pyridinone, have been theoretically investigated along the proton transfer (PT) reaction coordinate. The full geometry optimization has been performed along the PT reaction path. In the geometry optimization, the Hartree-Fock approximation and the configuration interaction scheme with single excitations have been employed. The energy calculations at the optimized geometries have been performed with the complete-active space self-consistent field (CASSCF) method followed by second-order perturbation theory calculations, employing the CASSCF wave function as the reference. We found that the near-degeneracy between the ππ* and nπ* excited singlet states, which is removed upon methyl substitution, might be the factor which differentiates the two systems with respect to the excited state intramolecular PT reaction. A simple vibrational model has been proposed for investigation of the dynamics of the process.
AB - The potential energy functions of the electronic ground state, as well as the lowest nπ* and ππ* excited singlet states of 3-hydroxy-4-pyridinone and 3-hydroxy-2-methyl-4-pyridinone, have been theoretically investigated along the proton transfer (PT) reaction coordinate. The full geometry optimization has been performed along the PT reaction path. In the geometry optimization, the Hartree-Fock approximation and the configuration interaction scheme with single excitations have been employed. The energy calculations at the optimized geometries have been performed with the complete-active space self-consistent field (CASSCF) method followed by second-order perturbation theory calculations, employing the CASSCF wave function as the reference. We found that the near-degeneracy between the ππ* and nπ* excited singlet states, which is removed upon methyl substitution, might be the factor which differentiates the two systems with respect to the excited state intramolecular PT reaction. A simple vibrational model has been proposed for investigation of the dynamics of the process.
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U2 - 10.1016/0301-0104(94)00392-N
DO - 10.1016/0301-0104(94)00392-N
M3 - Article
AN - SCOPUS:21844492461
SN - 0301-0104
VL - 193
SP - 67
EP - 78
JO - Chemical Physics
JF - Chemical Physics
IS - 1-2
ER -