Abstract
Various types of strongly enhanced infrared vibrational transitions, with transition moments comparable to those characteristic of allowed electronic transitions in visible or UV spectra, may ensue in spatially degenerate electronic states of nonlinear molecules. The intimate correlation between the intensity of the enhanced infrared vibrational transitions and the anomalous pure rotational microwave spectra and the Stark effect is elucidated. The rules of Child and Longuet-Higgins with regard to infrared activity and infrared intensity enhancements in electronically degenerate states require revision and extension when properly considering the ramifications of the Jahn–Teller effect and invoking the action of mixed quadratic nuclear potential terms. Significantly, the enhancements of IR transition moments should allow the observation of symmetrical free radicals and molecular ions whose laboratory concentrations are often below the level of detectability for ‘‘normal’’ IR transition strengths. In addition, these effects could lead to multi-enhancement effects in nonlinear infrared and Raman vibrational spectra as well as enhanced radiative and nonradiative vibrational relaxations.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
