Photoionization of anthracene and anthracene derivatives

• Published in: Journal of photochemistry and photobiology. A, Chemistry. Vol. 125; no. 1; pp. 47 - 56
• Main Authors: Zimmermann, C., Mohr, M., Zipse, H., Eichberger, R., Schnabel, W.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01.08.1999; Elsevier Science
• Subjects: Anthracene derivatives; Atomic and molecular physics; Autoionization, photoionization, and photodetachment; Exact sciences and technology; Intramolecular charge transfer; Molecular properties and interactions with photons; Photoionization; Photon interactions with molecules; Physics; Photoionization; Anthracene derivatives; Intramolecular charge transfer; Organic solvents; Electron transfer; Tricyclic compound; Experimental study; Condensed benzenic compound; Luminescence decay; Quantum efficiency; Near ultraviolet radiation; Acetonitrile; Dilute solution; Kinetics; Organic compounds
• ISSN: 1010-6030; 1873-2666
• DOI: 10.1016/S1010-6030(99)00094-5

Anthracene ( III) and the derivatives 9-methoxymethylanthracene ( IV), 9-cyanoanthracene ( V) and (E-3-phenyl-prop-2-ene-1-yl-(anthracene-9-methyl)-ether) ( I) were subjected to irradiation at λ inc=347 nm in dilute deoxygenated acetonitrile solution at room temperature. With the aid of the flash photolysis method employing fluorescence, optical absorption and electrical conductivity measurements the monophotonic photoionization and the formation of free ions was evidenced for compounds III– V. In the case of the bichromophoric compound I a photocurrent was not observed although a transient optical absorption attributable to the radical anion of the arthracene moiety was detected. Moreover, the fluorescence lifetime of I was found to be definitely shorter than that of IV (model compound). On this basis it was concluded that a certain fraction of electronically excited singlet states of I is deactivated via intramolecular electron transfer. The transient zwitter ions formed in this way, overwhelmingly undergo a self-reaction thus regenerating I, but a small portion undergoes an intramolecular Diels–Alder reaction forming VI, the only photoproduct. The quantum yield is Φ( VI)≤0.04.