Abstract
Raman studies of diphenylhexatriene in the first excited singlet state evidence strong vibronic coupling between two close 1Bu/2Ag states. The geometrical change after photoexcitation contains a dominant contribution of a low-frequency mode with bu symmetry near 40 cm-1. This mode is identified as a relatively strong line in the Raman spectrum. Vibronic coupling mainly affects two C=C stretching Raman bands near 1700 cm-1. A two-dimensional effective potential for the lowest excited singlet state is derived which models the coupling between the coordinate of the 40 cm-1 mode and the C=C stretching coordinate, thereby explaining the occurrence of the two bands and their strong solvent shift. The model gives, in the zero gap limit, a double-well potential for the C=C stretching coordinate, due to the pseudo-Jahn-Teller effect. Modulation of this potential by the low-frequency cycle explains the spectral broadening observed in the Raman spectra.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 56-62 |
| Number of pages | 7 |
| Journal | Chemical Physics Letters |
| Volume | 295 |
| Issue number | 1-2 |
| State | Published - Oct 2 1998 |
| Externally published | Yes |
Fingerprint
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Spectroscopy
- Atomic and Molecular Physics, and Optics
Cite this
Strong vibronic coupling in the first excited singlet state of diphenylhexatriene by an asymmetric low-frequency mode. / Pfeiffer, M.; Werncke, W.; Wachsmann-Hogiu, Sebastian; Kummrow, A.; Lau, A.
In: Chemical Physics Letters, Vol. 295, No. 1-2, 02.10.1998, p. 56-62.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Strong vibronic coupling in the first excited singlet state of diphenylhexatriene by an asymmetric low-frequency mode
AU - Pfeiffer, M.
AU - Werncke, W.
AU - Wachsmann-Hogiu, Sebastian
AU - Kummrow, A.
AU - Lau, A.
PY - 1998/10/2
Y1 - 1998/10/2
N2 - Raman studies of diphenylhexatriene in the first excited singlet state evidence strong vibronic coupling between two close 1Bu/2Ag states. The geometrical change after photoexcitation contains a dominant contribution of a low-frequency mode with bu symmetry near 40 cm-1. This mode is identified as a relatively strong line in the Raman spectrum. Vibronic coupling mainly affects two C=C stretching Raman bands near 1700 cm-1. A two-dimensional effective potential for the lowest excited singlet state is derived which models the coupling between the coordinate of the 40 cm-1 mode and the C=C stretching coordinate, thereby explaining the occurrence of the two bands and their strong solvent shift. The model gives, in the zero gap limit, a double-well potential for the C=C stretching coordinate, due to the pseudo-Jahn-Teller effect. Modulation of this potential by the low-frequency cycle explains the spectral broadening observed in the Raman spectra.
AB - Raman studies of diphenylhexatriene in the first excited singlet state evidence strong vibronic coupling between two close 1Bu/2Ag states. The geometrical change after photoexcitation contains a dominant contribution of a low-frequency mode with bu symmetry near 40 cm-1. This mode is identified as a relatively strong line in the Raman spectrum. Vibronic coupling mainly affects two C=C stretching Raman bands near 1700 cm-1. A two-dimensional effective potential for the lowest excited singlet state is derived which models the coupling between the coordinate of the 40 cm-1 mode and the C=C stretching coordinate, thereby explaining the occurrence of the two bands and their strong solvent shift. The model gives, in the zero gap limit, a double-well potential for the C=C stretching coordinate, due to the pseudo-Jahn-Teller effect. Modulation of this potential by the low-frequency cycle explains the spectral broadening observed in the Raman spectra.
UR - http://www.scopus.com/inward/record.url?scp=0002397665&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0002397665&partnerID=8YFLogxK
M3 - Article
VL - 295
SP - 56
EP - 62
JO - Chemical Physics Letters
JF - Chemical Physics Letters
SN - 0009-2614
IS - 1-2
ER -