Synthesis and characterization of fluorescent molecular switches based on perylene diimide dyads

• Autores: Rafael Sánchez Sánchez
• Directores de la Tesis: J. L. Bourdelande (codir. tes.), Gonzalo Guirado (codir. tes.), Jordi Hernando Campos (codir. tes.)
• Lectura: En la Universitat Autònoma de Barcelona ( España ) en 2011
• Idioma: español
• Tribunal Calificador de la Tesis: J. Marquet Cortés (presid.), Ezequiel Pérez-Inestrosa (secret.), Christophe Coudret (voc.)
• Materias:
  • Física
    • Química física
      • Electroquímica
      • Fotoquímica
  • Química
    • Química orgánica
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• Resumen

  • The present thesis work is focused on the preparation of new highly fluorescent molecular switches, systems that can be interconverted between two stables states with different properties. One of the most common limitations of this type of systems described in the bibliography so far is the destructive read-out. This process consists on an undesired interconversion between one of the two states of the switch as a consequence of the fluorescence measurement and it is widely observed in those systems that modulate its fluorescence through resonance energy transfer mechanisms (RET). One of the most promising strategies consists on the preparation of molecular switches based on the covalent linkage of a highly fluorescent moiety and a photochromic unit able to interconvert between two states upon the application of a external stimulus, whose fluorescence emission of the Off state is deactivated by a photoinduced electron transfer mechanism (PET). In order to reach this goal, the systems proposed in this work are constituted by perylene diimide derivatives (PDI), a fluorophore with high fluorescence quantum yield (~ 1), and by different of photochromic compounds, which must modulate the emission of the fluorophore depending on their state. Therefore, these systems must present a highly fluorescent state On, and a weakly fluorescent Off. In particular, the fluorescence modulators employed in this work are: (i) azobenzene and stilbene units, which present trans-cis isomerism and (ii) dithienylethylene derivatives (DTE), which can be interconverted between their open and closed states. From previous results found in the literature, it has been demonstrated that the interconversion between the two possible states of the mentioned photochromic units can be induced photo-, electrochemically and/or thermally, thus allowing the preparation of multi-addressable fluorescent molecular switches, which could be used ultimately for constructing electro-optical systems and devices.