title: Charge-recombination fluorescence from push-pull electronic systems constructed around amino-substituted styryl-BODIPY dyes.
abstract: A small series of donor-acceptor molecular dyads has been synthesized and fully characterized. In each case, the acceptor is a dicyanovinyl unit and the donor is a boron dipyrromethene (BODIPY) dye equipped with a single styryl arm bearing a terminal amino group. In the absence of the acceptor, the BODIPY-based dyes are strongly fluorescent in the far-red region and the relaxed excited-singlet states possess significant charge-transfer character. As such, the emission maxima depend on both the solvent polarity and temperature. With the corresponding push-pull molecules, there is a low-energy charge-transfer state that can be observed by both absorption and emission spectroscopy. Here, charge-recombination fluorescence is weak and decays over a few hundred picoseconds or so to recover the ground state. Overall, these results permit evaluation of the factors affecting the probability of charge-recombination fluorescence in push-pull dyes. The photophysical studies are supported by cyclic voltammetry and DFT calculations.
authors.affiliation: LCOSA, ICPEES, UMR7515, CNRS/Université de Strasbourg/ECPM, 25 rue Becquerel, 67087 Strasbourg, Cedex 02 (France), Fax: (+33) 3-68-85-27-61.
authors.forename: Adela
authors.initials: A
authors.lastname: Nano
authors.forename: Raymond
authors.initials: R
authors.lastname: Ziessel
authors.forename: Patrycya
authors.initials: P
authors.lastname: Stachelek
authors.forename: Anthony
authors.initials: A
authors.lastname: Harriman
mesh_terms: D001896:Boron Compounds / Q000737:chemistry*; D004396:Coloring Agents / Q000737:chemistry*; D004563:Electrochemistry; D004735:Energy Transfer; D005453:Fluorescence; D005456:Fluorescent Dyes / Q000737:chemistry*; D011789:Quantum Theory; D013343:Styrenes / Q000737:chemistry*
chemical_list: C095489:4,4-difluoro-4-bora-3a,4a-diaza-s-indacene; D001896:Boron Compounds; D004396:Coloring Agents; D005456:Fluorescent Dyes; D013343:Styrenes
keywords: donor-acceptor systems; electrochemistry; electron transfer; fluorescence; photophysics