Improved determination of structural changes of 2-pyridone-(H2O)1 upon electronic excitation.
The change of the 2-pyridone-water cluster (2PYH(2)O) structure upon electronic excitation is determined by a Franck-Condon analysis of the intensities in the fluorescence emission spectra obtained via excitation of three different vibronic bands as well as a structural fit based on the rotational constants of eight isotopomers that have been reported by Held and Pratt (J. Am. Chem. Soc., 1993, 115, 9708]. A total of 93 emission band intensities were fit, together with the changes of rotational constants of 8 isotopomers. The geometry change upon electronic excitation to the pipi* state can be described by a strong and unsymmetrical elongation of the hydrogen bonds, a contraction of the OH bond involved in the cyclic cluster arrangement, and an unsymmetrical ring deformation. The resulting geometry changes are interpreted on the basis of ab initio calculations.
Brause
Robert
R
Heinrich-Heine-Universität, Institut für Physikalische Chemie I, D-40225 Düsseldorf, Germany.
Schmitt
Michael
M
Kleinermanns
Karl
K
D003198:Computer Simulation; D004583:Electrons; D008958:Models, Molecular; D015394:Molecular Structure; D011728:Pyridones / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
D011728:Pyridones; D014867:Water; C017679:2-hydroxypyridine