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|Title: ||Photochemistry and photophysics of thienocarbazoles|
|Authors: ||Seixas de Melo, J.|
Ferreira, Isabel C.F.R.
Queiroz, Maria João R.P.
|Issue Date: ||2003|
|Publisher: ||Wiley Intersicence|
|Citation: ||Photochemistry and Photobiology. ISSN 1751-1097 (2003) p. 121-128|
|Abstract: ||Two methylated thienocarbazoles and two of their synthetic
nitro-precursors have been examined by absorption, luminescence,
laser flash photolysis and photoacoustic techniques.
Their spectroscopic and photophysical characterization involves
fluorescence spectra, fluorescence quantum yields and
lifetimes, and phosphorescence spectra and phosphorescence
lifetimes for all the compounds. Triplet–singlet difference
absorption spectra, triplet molar absorption coefficients,
triplet lifetimes, intersystem crossing S1 ~~→T1 and singlet
molecular oxygen yields were obtained for the thienocarbazoles.
In the case of the thienocarbazoles it was found that the
lowest-lying singlet and triplet excited states, S1 and T1, are of
╥, ╥* origin, whereas for their precursors S1 is n,╥*, and T1 is
╥, ╥*. In both thienocarbazoles it appears that the thianaphthene
ring dictates the S1 ~~→T1 yield, albeit there is less
predominance of that ring in the triplet state of the linear
thienocarbazole, which leads to a decrease in the observed /T value|
|Appears in Collections:||BB - Artigos em Revistas Indexados ao ISI|
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