Photochemical properties of (7-benzothiazol-2-yl-9,9-didecylfluoren-2-yl)diphenylamine under one- and two-photon excitation

• Published in: Journal of photochemistry and photobiology. A, Chemistry. Vol. 162; no. 2; pp. 569 - 574
• Main Authors: Belfield, Kevin D, Bondar, Mykhailo V, Przhonska, Olga V, Schafer, Katherine J
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.03.2004
• Subjects: Fluorene derivatives; Photochemical quantum yield; Photodecomposition; Photostability; Two-photon excitation; Photodecomposition; Fluorene derivatives; Photochemical quantum yield; Two-photon excitation; Photostability
• ISSN: 1010-6030; 1873-2666
• DOI: 10.1016/S1010-6030(03)00416-7

The photochemical properties of the fluorene derivative (7-benzothiazol-2-yl-9,9-didecylfluoren-2-yl)diphenylamine ( 1) in hexane and CH 2Cl 2 were studied under linear (one-photon) and nonlinear (two-photon) excitation. The quantum yield of the photochemical reaction, Φ, for 1 in hexane was in the range (3.5–5)×10 −5 for one-photon excitation (UVGL-25 and Xe-lamps) and was nearly the same under two-photon excitation (femtosecond laser with pulse duration 120 fs, average power ∼10 mW, repetition rate f=1 kHz). The values of Φ in CH 2Cl 2 were (2.5–4)×10 −5 for one-photon excitation and increased 50–80 times under two-photon excitation. This increase can be explained by an additional one-photon absorption process from the first electronically excited state, resulting in the observed enhancement in photochemical decomposition.