Singlet and Triplet (π, π*) Excited States of Zinc(II) Octaalkylporphyrins: A Time-Resolved Resonance-Raman Study

  • R. Kumble
  • G. R. Loppnow
  • S. Hu
  • S. E. Vitols
  • T. G. Spiro
Conference paper
Part of the Springer Proceedings in Physics book series (SPPHY, volume 74)

Abstract

The excited states of porphyrins and hydroporphyrins act as primary intermediates in processes ranging from biological energy transfer and electron transfer to photocatalysis and photodynamic therapy. We report resonance Raman (RR) spectra of the singlet S1 and triplet T1 excited states of zinc(II) octaethylporphyrin (ZnOEP) and zinc(II) etioporphyrin-I (ZnEtio), using picosecond and nanosecond RR techniques. Picosecond time-resolved resonance Raman experiments were performed using 532 nm photoexcitation pulses and 436 nm probe pulses (both 100 ps, 50 Hz); the experimental apparatus consisted of a mode-locked Nd:YAG laser (Coherent) in combination with a Nd:YAG regenerative amplifier (Continuum) and an H2 cell for stimulated Raman shifting. The apparatus used for nanosecond time-resolved RR experiments has been described previously [1]. Porphyrin samples were prepared in a nitrogen atmosphere at a concentration of 0.5 mM (tetrahydrofuran solvent).

Keywords

Zinc Ethyl Porphyrin Tetrahydrofuran Spiro 

References

  1. [1].
    Reed, R. A.; Purrello, Roberto; Prendergast, Kristine; Spiro, Thomas G. J. Phys. Chem. 1991, 95, 9720CrossRefGoogle Scholar
  2. [2]
    Gouterman, M. in The Porphyrins; Dolphin, D.; Academic Press: New York 1978; Vol. III, Chapter 1 and references thereinGoogle Scholar
  3. [3].
    Prendergast, K; Spiro, T. G. J. Phys. Chem. 1991, 95, 9728CrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 1994

Authors and Affiliations

  • R. Kumble
    • 1
  • G. R. Loppnow
    • 1
  • S. Hu
    • 1
  • S. E. Vitols
    • 1
  • T. G. Spiro
    • 1
  1. 1.Department of ChemistryPrinceton UniversityPrincetonUSA

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