Assignment of the low-frequency modes in trans-stilbene. Evidence for planarity in the isolated molecule
The authors report the assignment of low-frequency vibrations in the excitation spectrum and several dispersed fluorescence spectra of trans-stilbene. All transitions of significant intensity in the first 400 cm/sup -1/ of the excitation spectrum and the first 200 cm/sup -1/ of the dispersed fluorescence spectra are assigned with the use of only three modes, nu/sub 36/ (C/sub e/-Ph out-of-plane bend), nu/sub 37/ (C/sub e/-Ph torsion), and nu/sub 25/ (C/sub e/-C/sub e/-Ph in-plane bend). Only even quanta transitions involving nu/sub 36/ and nu/sub 37/ are observed, indicating that these modes are symmetry forbidden and that the molecule possesses an inversion center of symmetry. The rho-methyl-trans-stilbene spectrum also shows only even quanta transitions of nu/sub 37/ providing evidence that this molecule and, by analogy, trans-stilbene are both planar.
- Research Organization:
- Los Alamos National Lab., NM
- OSTI ID:
- 6421047
- Journal Information:
- J. Phys. Chem.; (United States), Vol. 91:11
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
STILBENE
MOLECULAR STRUCTURE
VIBRATIONAL STATES
DYE LASERS
EXCIMER LASERS
EXPERIMENTAL DATA
FLUORESCENCE SPECTROSCOPY
NORMAL-MODE ANALYSIS
VISIBLE SPECTRA
AROMATICS
DATA
EMISSION SPECTROSCOPY
ENERGY LEVELS
EXCITED STATES
GAS LASERS
HYDROCARBONS
INFORMATION
LASERS
LIQUID LASERS
NUMERICAL DATA
ORGANIC COMPOUNDS
SPECTRA
SPECTROSCOPY
400201* - Chemical & Physicochemical Properties
400500 - Photochemistry