title: Singlet oxygen quantum yield determination for a fluorene-based two-photon photosensitizer.
abstract: The quantum yield, Phi(Delta), of singlet oxygen generation under two-photon excitation has been determined for a fluorene derivative. A photochemical method was developed using 1,3-diphenylisobenzofuran (DPBF), a chemical quencher of 1O2, and 2-(9,9-didecyl-7-nitrofluoren-2-yl)benzothiazole (1) as a two-photon photosensitizer (PS). The photochemical kinetics of the quencher was measured by two different fluorescence methods. Fluorene 1 exhibited relatively high singlet oxygen quantum yield, Phi(Delta) approximately 0.4 +/- 0.1, and had a two-photon absorption cross-section of 28 +/- 5 GM. Thus, 1 may have potential for use as a two-photon PS in the near-IR spectral region for biomedical applications.
authors.affiliation: Department of Chemistry and College of Optics and Photonics, CREOL and FPCE, University of Central Florida, P.O. Box 162366, Orlando, Florida 32816-2366, USA. kbelfiel@mail.ucf.edu
authors.forename: Kevin D
authors.initials: KD
authors.lastname: Belfield
authors.forename: Mykhailo V
authors.initials: MV
authors.lastname: Bondar
authors.forename: Olga V
authors.initials: OV
authors.lastname: Przhonska
mesh_terms: D001572:Benzofurans / Q000737:chemistry; D005449:Fluorenes / Q000737:chemistry*; D007700:Kinetics; D015394:Molecular Structure; D010777:Photochemistry; D017785:Photons; D017319:Photosensitizing Agents; D011789:Quantum Theory; D026082:Singlet Oxygen / Q000737:chemistry*; D013050:Spectrometry, Fluorescence
chemical_list: D001572:Benzofurans; D005449:Fluorenes; D017319:Photosensitizing Agents; D026082:Singlet Oxygen; C041509:fluorene; C011238:1,3-diphenylisobenzofuran