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dc.contributor.author Nijegorodov, N.
dc.contributor.author Zvolinsky, V.
dc.contributor.author Luhanga, P.V.C.
dc.date.accessioned 2009-09-09T12:47:25Z
dc.date.available 2009-09-09T12:47:25Z
dc.date.issued 2008
dc.identifier.citation Nijegorodov, N. et al (2008) Photonics and photochemical stability of aromatic molecules, family related in -structure but different in planarity, rigidity and molecule symmetry, Journal of Photochemistry and Photobiology A: Chemistry, Vol. 196, No. 2-3, pp. 219-226 en_US
dc.identifier.issn 1010-6030
dc.identifier.uri http://hdl.handle.net/10311/367
dc.description.abstract Intramolecular processes and fluorescence properties of 32 specially chosen aromatic molecules, different in degrees of planarity and rigidity, but family related in -structure are experimentally and theoretically (using the PPP-method) studied at room temperature (293 K). The quantum yields of fluorescence , and decay times τf, of deaerated and non-deaerated cyclohexane solutions are measured. The oscillator strength fe, the fluorescence rate constants kf, the natural lifetimes τT o , and the intersystem crossing rate constants kST, are calculated. The investigations showed the following differences in the behaviour of the fluorescence parameters in transition from the non-planar molecule to the planar and more rigid-type: the value of the symmetry line wave-number υ00 (the frequency of the S0→S1 * transition) and the Stokes shift υST, decrease. The oscillator strength and fluorescence constant, normally decrease. The change in the quantum yield of the fluorescence depends upon the changes in the kf and kST values. Furthermore, the intersystem crossing rate constant generally decreases, sometimes very significantly. However, there are some interesting exceptions. For example, the kST value of the non-planar molecule of 9,10-diphenylanthracene is less than the kST value of the planar and very rigid molecule of anthracene. This important phenomenon is explained. The differences of the intramolecular processes of planar and non-planar molecules are discussed. The photochemical stability of planar and non-planar molecules is studied. The effect of planarity, rigidity and molecular symmetry upon laser properties is also traced. en_US
dc.language.iso en en_US
dc.publisher Elsevier Science Ltd. www.elsevier.com/locate/jphotochem en_US
dc.subject Planarity en_US
dc.subject Rigidity en_US
dc.subject Fluorescence and laser properties en_US
dc.title Photonics and photochemical stability of aromatic molecules, family related in -structure but different in planarity, rigidity and molecule symmetry en_US
dc.type Published Article en_US


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