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Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions
Published on: July 17, 2020
Tetrathiafulvalene porphyrins
Kent A Nielsen1, Eric Levillain, Vincent M Lynch
1Department of Physics and Chemistry, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark. joj@ifk.sdu.dk
Chemistry (Weinheim an Der Bergstrasse, Germany)
|November 28, 2008
Summary
Synthesized tetrathiafulvalene-annulated porphyrins exhibit electronic interactions between TTF units and the porphyrin core. These interactions significantly alter redox potentials and quench porphyrin fluorescence, which is restored upon TTF oxidation.
Area of Science:
- Materials Chemistry
- Supramolecular Chemistry
- Photochemistry
Background:
- Tetraphenylporphyrin (TPP) is a versatile macrocycle with applications in catalysis and sensing.
- Tetrathiafulvalene (TTF) is a strong electron donor with unique redox properties.
- Annulating electron donor/acceptor units onto porphyrin cores can modulate their photophysical and electrochemical behavior.
Purpose of the Study:
- To synthesize and characterize novel TTF-annulated porphyrins.
- To investigate the electronic interactions between TTF and TPP cores.
- To explore the impact of TTF annulation on redox potentials and fluorescence properties.
Main Methods:
- Synthesis of four TTF-annulated porphyrins (1-4) with varying numbers of TTF units.
- Absorption and fluorescence spectroscopy.
- Electrochemical investigations (cyclic voltammetry).
Main Results:
- Successful synthesis and characterization of TTF-annulated porphyrins.
- Evidence of electronic interactions between TTF and TPP in solution.
- Significant shifts in reduction potentials of the porphyrin core and oxidation potentials of the TTF units.
- Porphyrin fluorescence quenching in the neutral state, attributed to intramolecular electron transfer from TTF to TPP.
- Restoration of fluorescence upon oxidation of the TTF units.
Conclusions:
- The electronic communication between TTF and TPP units is confirmed.
- TTF annulation effectively tunes the redox properties of the porphyrin framework.
- Intramolecular electron transfer plays a crucial role in the photophysical properties of these systems.
- These TTF-annulated porphyrins show potential for applications in molecular electronics and sensing.
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