Resonance Raman scattering of ethylene: Evidence for a twisted geometry in the V state

Publisher Website
Google Scholar
Abstract
The resonance Raman spectra of ethylene obtained with 212.8 and 193.4 nm excitation are presented. With these excitation frequencies, on the red edge of the N → V absorption system, strong enhancement of the even overtones of the torsional coordinate is found. In addition, scattering to the carbon–carbon double bond stretching and the symmetric CH2 scissors modes show enhancement. These results demonstrate that the CH2 groups lie in mutually perpendicular planes in the nuclear equilibrium configuration of the V state, while the C–C bond distance has been lengthened and the HCH angles reduced relative to those of the ground state. These results are discussed within the context of the G16(2) dynamic point group and recent calculations.