Details

Autor(en) / Beteiligte

• Isosomppi, Marja
• Tkachenko, Nikolai V
• Efimov, Alexander
• Lemmetyinen, Helge

Titel

Photoinduced Electron Transfer in Double-Bridged Porphyrin−Fullerene Triads

Ist Teil von

• The journal of physical chemistry. A, Molecules, spectroscopy, kinetics, environment, & general theory, 2005-06, Vol.109 (22), p.4881-4890

Ort / Verlag

United States: American Chemical Society

Erscheinungsjahr

2005

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Electron and energy transfer reactions of porphyrin−porphyrin−fullerene triads (P2P1C) with controllable sandwich-like structures have been studied using spectroscopic and electrochemical methods. The stabile, stacked structure of the molecules was achieved applying a two-linker strategy developed previously for porphyrin−fullerene dyads. Different triad structures with altered linker positions, linker lengths, and center atoms of the porphyrin rings were studied. The final charge-separated (CS) state and the different transient states of the reactions have been identified and energies of the states estimated based on the experimental results. In particular, a complete CS state P2 +P1C- was achieved in a zinc porphyrin−free-base porphyrin−fullerene triad (ZnP 2 t9P 1 C) in both polar (benzonitrile) and nonpolar (toluene) solvents. The lifetime of this state was longer living in the nonpolar solvent. An outstanding feature of the ZnP 2 t9P 1 C triad is the extremely fast formation of the final CS state, P2 +P1C-. This state is formed after primary excitation of either zinc porphyrin or free-base porphyrin chromophores in less than 200 fs. Although the intermediate steps between the locally excited states and the final CS state were not time-resolved for this compound, the process is clearly multistep and the fastest ever observed for porphyrin-based compounds.