Assignment of the low-frequency modes in trans-stilbene. Evidence for planarity in the isolated molecule

Journal Article · Thu May 21 04:00:00 EDT 1987 · J. Phys. Chem.; (United States)

DOI:https://doi.org/10.1021/j100295a027· OSTI ID:6421047

Spangler, L H; van Zee, R; Zwier, T S

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), Journal Name: J. Phys. Chem.; (United States) Vol. 91:11; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
400500 -- Photochemistry
AROMATICS
DATA
DYE LASERS
EMISSION SPECTROSCOPY
ENERGY LEVELS
EXCIMER LASERS
EXCITED STATES
EXPERIMENTAL DATA
FLUORESCENCE SPECTROSCOPY
GAS LASERS
HYDROCARBONS
INFORMATION
LASERS
LIQUID LASERS
MOLECULAR STRUCTURE
NORMAL-MODE ANALYSIS
NUMERICAL DATA
ORGANIC COMPOUNDS
SPECTRA
SPECTROSCOPY
STILBENE
VIBRATIONAL STATES
VISIBLE SPECTRA