ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
Relative Raman scattering cross sections of totally symmetric vibrational modes of liquid methanol, ethanol, and ethylene glycol are measured as a function of excitation wavelength in the preresonant spectral region 37 593–47 393 cm−1. Raman spectra are also obtained with 50 043 and 54 198 cm−1 excitation, the latter energy being directly resonant with the first excited state of the alcohols. The data indicate that the first three excited electronic states (with transition energies of approximately 54 600, 62 500, and 66 000 cm−1, respectively) make no significant contribution to the Raman scattered intensities and are nearly entirely Rydberg in character. The low-lying electronic structure of ethylene glycol appears to be primarily Rydberg in character as well. The dominant C–H and O–H stretching modes gain intensity largely from valence state(s) with transition energies near 70 000 cm−1, while the C–O stretching and CH2,3 bending modes gain intensity from even higher energy states (∼85 000 cm−1).
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.465889
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