Time-resolved resonance Raman spectra of the triplet state and the radical cation of 5-dibenzosuberenol and its photoionization mechanism

✍ Scribed by Jiro Abe; Noboru Kunimatsu; Atsuhiko Shimojima; Hiroaki Takahashi

• Publisher: Elsevier Science
• Year: 1991
• Tongue: English
• Weight: 467 KB
• Volume: 178
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(91)87018-7

✦ Synopsis

Time-resolved resonance Raman spectra are obtained for the lowest excited triplet state T, and the radical cation of 5-dibenzosuberenol (DBCH-5-01). It is concluded, based on the large downshifts of the Raman bands assignable to the C=C stretch of the central ring, that the C=C bond is weakened markedly both in the T, state and in the radical cation; the weakening is much more pronounced in the T, state. Dependence on the intensity and wavelength of the pump laser pulse indicates that the production of the radical cation is biphotonic via the S, state and that the intersystem crossing from S, to T, is much slower from low vibrational levels than from higher vibrational levels, resulting in the very small yield of the T, state when photolysed by 340 nm UV light.