Table of Contents
Laser Chemistry
Volume 10, Issue 5-6, Pages 333-347

Time-Resolved Resonance Raman Spectroscopy of Photochemical Reactive Intermediates: Radical Cation of Fluorene and Triplet State of Fluorene, Dibenzofuran and Dibenzothiophen

1Laboratoire de Spectrochimie Infrarouge et Raman, CNRS, USTL, Villeneuve d’Ascq 59655, France
2Laboratoire de Spectrochimie Infrarouge et Raman, CNRS, 2 rue Henri Dunant, Thiais 94320, France

Received 15 October 1989; Accepted 5 January 1990

Copyright © 1990 Hindawi Publishing Corporation. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


The time-resolved Raman spectra of the first triplet state–in resonance with the TnT1 absorption at 370 nm–and of the radical cation transient–in resonance with the R+R+ absorptions at 370 nm and in the 560-600 nm range-are reported for fluorene. The triplet state Raman spectra of dibenzofuran and dibenzothiophen are also given. The vibrational assignments, resonance Raman activity and intensity enhancement effects are studied. On this basis, the structures and electronic configurations of the triplet state and radical cation transients and the nature of the resonant TnT1 and R+R+ transitions are discussed. It turns out from this investigation that the title molecules present close analogies with biphenyl. The insertion of a methylene group or a heteroatom does not disturb markedly the electronic properties of the ground state, the first triplet state and the radical cation transient of biphenyl.