Solvent and temperature effects on the fluorescence and competitive photoreactions of cis-9-styrylanthracene
- 33 Downloads
A fluorimetric and photochemical study of cis-9-styrylanthracene as a function of temperature has been carried out in different solvents with the aim of answering some open questions about the behavior of its first excited singlet state, S1. In non-polar solvents, a parallel photoreactive pathway, leading to a cyclization adduct, was found to compete with fluorescence and isomerization already at 200 K, its contribution increasing markedly with temperature. The cis » trans photoisomerization occurs prevalently by a triplet mechanism, a detectable contribution of diabatic and adiabatic isomerization in S1 being operative in these solvents from room temperature upwards. In polar solvents, the main deactivation pathway competitive with fluorescence is isomerization to trans, which occurs prevalently through a mixed singlet mechanism with a major diabatic and a minor adiabatic components.
KeywordsPolar Solvent Arrhenius Parameter Laser Flash Photolysis Isomerization Yield Triplet Mechanism
Unable to display preview. Download preview PDF.
- 1.For a review article, see: J. Saltiel and Y.-P. Sun. In: Photochromism: Molecules and Systems, H. Dürr and H. Bouas-Laurent (Eds.), Elsevier, Amsterdam, p. 64 (1990).Google Scholar
- 3.T. Arai, T. Karatsu, H. Misawa, Y. Kuriyama, H. Okamoto, T. Hiresaki, H. Furuuchi, H. Zeng, H. Sakuragi and K. Tokumaru, Pure Appl. Chem., 60, 989 (1988); K. Tokumaru and T. Arai, J. Photochem. Photobiol. A: Chem., 65, 1 (1992); T. Arai and K. Tokumaru, Chem. Rev., 93, 23 (1993) and references cited therein.CrossRefGoogle Scholar
- 6. a)G. Bartocci, F. Masetti, U. Mazzucato and A. Spalletti, Euchem Conference on Photoisomerism and Rotamerism in Organic Molecules, Assisi, P-6 (1988); b) G. Galiazzo, A. Spalletti F. Elisei and G. Gennari, Gazz. Chim. Ital., 119, 277 (1989).Google Scholar
- 10.Hyper Chem Release 3 package from Autodesk, Inc.Google Scholar
- 11.J.B. Birks, Photophysics of Aromatic Molecules, Wiley, London, p. 127 (1970).Google Scholar