Efficient charge separation in porphyrin-fullerene-ligand complexes

Chemistry. 2001;7(4):816-27. doi: 10.1002/1521-3765(20010216)7:4<816::aid-chem816>3.0.co;2-a.

Abstract

Photoprocesses associated with the complexation of a pyridine-functionalized C60 fullerene derivative to ruthenium- and zinc-tetraphenylporphyrins (tpp) have been studied by time-resolved optical and transient EPR spectroscopies. It has been found that upon irradiation in toluene, a highly efficient triplet-triplet energy transfer governs the deactivation of the photoexcited [Ru(tpp)], while electron transfer (ET) from the porphyrin to the fullerene prevails in polar solvents. Complexation of [Zn(tpp)] by the fullerene derivative is reversible and, following excitation of the [Zn(tpp)], gives rise to very efficient charge separation. In fluid polar solvents such as THF and benzonitrile, radical-ion pairs (RPs) are generated both by intramolecular ET inside the complex and by intermolecular ET in the uncomplexed form. Charge-separated states have lifetimes of about 10 micros in THF and several hundred of microseconds in benzonitrile at room temperature.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Carbon / chemistry*
  • Electron Spin Resonance Spectroscopy
  • Fullerenes*
  • Ions
  • Kinetics
  • Molecular Structure
  • Porphyrins / chemistry*
  • Spectrometry, Fluorescence

Substances

  • Fullerenes
  • Ions
  • Porphyrins
  • Carbon
  • fullerene C60