title: Diiodobodipy-styrylbodipy Dyads: Preparation and Study of the Intersystem Crossing and Fluorescence Resonance Energy Transfer.
abstract: 2,6-Diiodobodipy-styrylbodipy dyads were prepared to study the competing intersystem crossing (ISC) and the fluorescence-resonance-energy-transfer (FRET), and its effect on the photophysical property of the dyads. In the dyads, 2,6-diiodobodipy moiety was used as singlet energy donor and the spin converter for triplet state formation, whereas the styrylbodipy was used as singlet and triplet energy acceptors, thus the competition between the ISC and FRET processes is established. The photophysical properties were studied with steady-state UV-vis absorption and fluorescence spectroscopy, electrochemical characterization, and femto/nanosecond time-resolved transient absorption spectroscopies. FRET was confirmed with steady state fluorescence quenching and fluorescence excitation spectra and ultrafast transient absorption spectroscopy (kFRET = 5.0 × 10(10) s(-1)). The singlet oxygen quantum yield (ΦΔ = 0.19) of the dyad was reduced as compared with that of the reference spin converter (2,6-diiodobodipy, ΦΔ = 0.85), thus the ISC was substantially inhibited by FRET. Photoinduced intramolecular electron transfer (ET) was studied by electrochemical data and fluorescence quenching. Intermolecular triplet energy transfer was studied with nanosecond transient absorption spectroscopy as an efficient (ΦTTET = 92%) and fast process (kTTET = 5.2 × 10(4) s(-1)). These results are useful for designing organic triplet photosensitizers and for the study of the photophysical properties.
authors.affiliation: †State Key Laboratory of Fine Chemicals, School of Chemical Engineering, Dalian University of Technology, E-208 West Campus, 2 Ling-Gong Road, Dalian 116024, P. R. China.
authors.forename: Zhijia
authors.initials: Z
authors.lastname: Wang
authors.affiliation: ‡Department of Chemistry, Center for Photochemical Sciences, Bowling Green State University, Bowling Green, Ohio 43403, United States.
authors.forename: Yun
authors.initials: Y
authors.lastname: Xie
authors.affiliation: †State Key Laboratory of Fine Chemicals, School of Chemical Engineering, Dalian University of Technology, E-208 West Campus, 2 Ling-Gong Road, Dalian 116024, P. R. China.
authors.forename: Kejing
authors.initials: K
authors.lastname: Xu
authors.affiliation: †State Key Laboratory of Fine Chemicals, School of Chemical Engineering, Dalian University of Technology, E-208 West Campus, 2 Ling-Gong Road, Dalian 116024, P. R. China.
authors.forename: Jianzhang
authors.initials: J
authors.lastname: Zhao
authors.affiliation: ‡Department of Chemistry, Center for Photochemical Sciences, Bowling Green State University, Bowling Green, Ohio 43403, United States.
authors.forename: Ksenija D
authors.initials: KD
authors.lastname: Glusac
mesh_terms: D004583:Electrons; D005296:Ferrous Compounds / Q000737:chemistry; D031541:Fluorescence Resonance Energy Transfer; D000075163:Metallocenes; D015394:Molecular Structure; D010084:Oxidation-Reduction; D055668:Photochemical Processes; D011522:Protons; D026082:Singlet Oxygen / Q000737:chemistry; D012997:Solvents / Q000737:chemistry; D014050:Toluene / Q000737:chemistry; D014269:Trifluoroacetic Acid / Q000737:chemistry
chemical_list: D005296:Ferrous Compounds; D000075163:Metallocenes; D011522:Protons; D012997:Solvents; D026082:Singlet Oxygen; D014050:Toluene; D014269:Trifluoroacetic Acid; C004998:ferrocene