Abstract
Liquid phase overtone spectra are measured in the spectral regions of CH-stretching local modes corresponding to ΔvCH=2–7 for acetophenone, ΔvCH=2–8 for isobutyrophenone, and to ΔvCH=2–6 for biacetyl and isobutyrophenone-d5. The spectra are assigned in terms of the local mode model. The intensities of the aryl CH overtones are quantitatively determined as a function of ΔvCH. The intensities of the alkyl CH-stretching overtones of all four molecules and the intensities of the aryl CD-stretching overtones of isobutyrophenone-d5 appear to decrease smoothly and exponentially with increasing ΔvCH (ΔvCD). However, the intensities of the aryl CH–stretching overtones of isobutyrophenone actually increase from ΔvCH=6 to ΔvCH=7 to ΔvCH=8. A similar but less pronounced anomaly is observed for the intensities of the aryl overtones of acetophenone. The results are interpreted in terms of a vibronic coupling contribution to overtone intensity which involves excited electronic states.
Sign-in/Register to access full text options 
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.
