THE FAR ULTRAVIOLET SPECTRA OF ETHYLENE AND PERDEUTERO-ETHYLENE
Loading...
Date
1966
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Ohio State University
Abstract
The $prediction^{1,2}$ that in the $\pi^{\ast} (V)$ state of ethylene the two $CH_{2}$ groups are twisted relative to each other has been validated by an analysis of the vibrational structure of the $\pi \rightarrow \pi^{\ast}$ transition in ethylene and perdeuteroethylene. In ethylene an irregular progression with a mean spacing of $803 \pm 48 cm^{-1}$ is found; in perdeuteroethylene the corresponding progression has a spacing of $547 \pm 18 cm^{-1}$. Hot bands are found 278 and $201 cm^{-1}$ to the red of the main vibrational sub-bands in ethylene and perdeuteroethylene respectively, indicating that the ground state vibrations responsible for both the vibronic and hot bands lie at 1081 and $748 cm^{-1}$. These values are comparable with the torsional vibration $(\nu_{4})$ of 1027 and $726 cm^{-1}$ of these molecules, $respectively.^{2}$ Comparison of the isotopic shifts of the vibronic bands of these two molecules provides a primary quantum numbering of the bands, from which origins of the transitions can be deduced. The $\pi \rightarrow \pi^{\ast}$ transition is found to originate at $46,712\pm 33 cm^{-1}$ in ethylene and $46,948 \pm 16 cm^{-1}$ in deuteroethylene.
Description
$^{1}$ R. S. Mulliken and C. C. J. Roothaan, Chem. Rev. 41, 219 (1947). $^{2}$ A. D. Walsh, J. Chem. Soc., 1953, 2325. $^{3}$ R. L. Arnett and B. L. Crawford, Jr., J. Chem. Phys. 18, 118 (1950).
Author Institution: National Institutes of Health, NIAMD
Author Institution: National Institutes of Health, NIAMD