title: Excited-state absorption and anisotropy properties of two-photon absorbing fluorene derivatives.
abstract: The electronic structure of fluorene derivatives N-(7-benzothiazol-2-yl-9,9-bis-decyl-9H-fluoren-2-yl)-acetamide (1); 9,9-didecyl-2,7-bis-(N,N-benzothiazoyl)fluorene (2); 4,4'-{[9,9-bis(ethyl)-9H-fluorene-2,7-diyl]di-2,1-ethenediyl}bis(N,N-diphenyl)benzeneamine (3); and 4,4',4"{[9,9-bis(ethyl)-9H-fluorene-2,4,7-triyl]tri-2,1-ethenediyl}tris(N,N-diphenyl)benzeneamine (4) were investigated by a steady-state spectral technique, quantum-chemical calculations, and a picosecond pump-probe method. These derivatives are of interest for their relatively high two-photon absorption. The steady-state excitation anisotropy spectra reveal the nature of the ground-state absorption bands. Semiempirical quantum-chemical calculations of the fluorene derivatives (AM1, ZINDO/S) show good agreement with experimental data. The spectral positions and alignment of various electronic transitions of derivatives 1-4 were estimated from their excited-state absorption and anisotropy spectra.
authors.affiliation: Department of Chemistry and College of Optics and Photonics, Center for Research and Education in Optics and Lasers and Florida Photonics Center of Excellence, University of Central Florida, Orlando, Florida 32816-2366, USA. kbelfiel@mai.ucf.edu
authors.forename: Kevin D
authors.initials: KD
authors.lastname: Belfield
authors.forename: Mykhailo V
authors.initials: MV
authors.lastname: Bondar
authors.forename: I
authors.initials: I
authors.lastname: Cohanoschi
authors.forename: Florencio E
authors.initials: FE
authors.lastname: Hernandez
authors.forename: Oleksiy D
authors.initials: OD
authors.lastname: Kachkovsky
authors.forename: Olga V
authors.initials: OV
authors.lastname: Przhonska
authors.forename: Sheng
authors.initials: S
authors.lastname: Yao
mesh_terms: D000042:Absorption; D016880:Anisotropy; D003198:Computer Simulation; D005449:Fluorenes / Q000032:analysis* / Q000737:chemistry*; D036641:Microscopy, Fluorescence, Multiphoton / Q000379:methods*; D008956:Models, Chemical; D008958:Models, Molecular; D013050:Spectrometry, Fluorescence / Q000379:methods*
chemical_list: D005449:Fluorenes