Resonance hyper-Raman scattering in the VUV. Femtosecond dynamics of the predissociated C state of methyl iodide

✍ Scribed by D.J. Campbell; L.D. Ziegler

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 575 KB
• Volume: 201
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(93)85050-x

✦ Synopsis

The polarization-resolved resonance hyper-Raman (RHR) scattering of CHJ vapor is observed as blue mcident radiation is tuned through two-photon resonance with the origin absorption band ofthe predissociative c+x Rydberg transition in the WV ( 183-175 nm). These results demonstrate the ability of this nonlinear Raman technique to probe the ultrafast dynamics of molecular levels in the VUV. The C-state lifetime is determined to be 180+ 30 fs by fits of theory to the depolarization ratio excitation profile and mvibrational hyper-Raman bandshapes. Hence, predissociation is approximately three times faster on the C-state than the B-state surface of CHII (T= 500 fs). Additionally, the depolarization ratio dispersion and RHR bandshapes indicate mode specific predissociation effects, at least for the us methyl iodine vibronic C-state level, just as found for the B state.