Abstract
We present a combined experimental and theoretical study of vibrational modes and excited-state geometry changes of betaine-30 (B-30). Infrared and Raman spectra were recorded under electronic off-resonant excitation conditions and also in resonance with the charge transfer transition of B-30. Comparing these spectra with the corresponding vibrational patterns calculated by Hartree-Fock methods we obtained the assignments of the vibrational modes. Excited-state geometry changes were calculated for a smaller model system of B-30 using configuration interaction with single excitations. The calculations predict that the central phenoxide and pyridinium rings move from a twisted conformation in the electronic ground state into a perpendicular position in the first excited state. In addition, the pyridinium ring tilts and the nitrogen atom becomes pyramidalized. In correspondence, we measured two strong low-wavenumber Raman bands with large origin shifts at 291 and 133 cm-1. They were assigned to N-inversion and torsional vibrational modes and are expected to mediate the excited state and back-electron transfer reaction of B-30. Copyright (C) 2000 John Wiley And Sons, Ltd.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 797-803 |
| Number of pages | 7 |
| Journal | Journal of Raman Spectroscopy |
| Volume | 31 |
| Issue number | 8-9 |
| State | Published - 2000 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Spectroscopy
Cite this
Vibrational analysis and excited-state geometric changes of betaine-30 derived from Raman and infrared spectra combined with ab initio calculations. / Wachsmann-Hogiu, Sebastian; Dreyer, J.; Pfeiffer, M.; Brzezinka, K. W.; Werncke, W.
In: Journal of Raman Spectroscopy, Vol. 31, No. 8-9, 2000, p. 797-803.Research output: Contribution to journal › Article
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TY - JOUR
T1 - Vibrational analysis and excited-state geometric changes of betaine-30 derived from Raman and infrared spectra combined with ab initio calculations
AU - Wachsmann-Hogiu, Sebastian
AU - Dreyer, J.
AU - Pfeiffer, M.
AU - Brzezinka, K. W.
AU - Werncke, W.
PY - 2000
Y1 - 2000
N2 - We present a combined experimental and theoretical study of vibrational modes and excited-state geometry changes of betaine-30 (B-30). Infrared and Raman spectra were recorded under electronic off-resonant excitation conditions and also in resonance with the charge transfer transition of B-30. Comparing these spectra with the corresponding vibrational patterns calculated by Hartree-Fock methods we obtained the assignments of the vibrational modes. Excited-state geometry changes were calculated for a smaller model system of B-30 using configuration interaction with single excitations. The calculations predict that the central phenoxide and pyridinium rings move from a twisted conformation in the electronic ground state into a perpendicular position in the first excited state. In addition, the pyridinium ring tilts and the nitrogen atom becomes pyramidalized. In correspondence, we measured two strong low-wavenumber Raman bands with large origin shifts at 291 and 133 cm-1. They were assigned to N-inversion and torsional vibrational modes and are expected to mediate the excited state and back-electron transfer reaction of B-30. Copyright (C) 2000 John Wiley And Sons, Ltd.
AB - We present a combined experimental and theoretical study of vibrational modes and excited-state geometry changes of betaine-30 (B-30). Infrared and Raman spectra were recorded under electronic off-resonant excitation conditions and also in resonance with the charge transfer transition of B-30. Comparing these spectra with the corresponding vibrational patterns calculated by Hartree-Fock methods we obtained the assignments of the vibrational modes. Excited-state geometry changes were calculated for a smaller model system of B-30 using configuration interaction with single excitations. The calculations predict that the central phenoxide and pyridinium rings move from a twisted conformation in the electronic ground state into a perpendicular position in the first excited state. In addition, the pyridinium ring tilts and the nitrogen atom becomes pyramidalized. In correspondence, we measured two strong low-wavenumber Raman bands with large origin shifts at 291 and 133 cm-1. They were assigned to N-inversion and torsional vibrational modes and are expected to mediate the excited state and back-electron transfer reaction of B-30. Copyright (C) 2000 John Wiley And Sons, Ltd.
UR - http://www.scopus.com/inward/record.url?scp=0033647087&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0033647087&partnerID=8YFLogxK
M3 - Article
AN - SCOPUS:0033647087
VL - 31
SP - 797
EP - 803
JO - Journal of Raman Spectroscopy
JF - Journal of Raman Spectroscopy
SN - 0377-0486
IS - 8-9
ER -