Systematic Trends in Metalloporphyrin Optical Spectra

M. Y Rachel Wang, Brian M. Hoffman

Research output: Contribution to journalArticle

41 Scopus citations


We report the effects of axial ligands (L) on the optical spectra of cobalt-substituted myoglobin, horseradish peroxidase, and cytochrome P450cam. In addition, we present data for a series of octapyrrole-substituted zinc porphyrin complexes. The response of a metalloporphyrin to the change of ligand is more complicated than previously noted and is not the same for pyrrole-substituted porphyrins as it is for meso-tetraaryl-substituted compounds. Perturbations by the ligand not only shift the overall spectrum as previously observed but also systematically change the frequency difference between the Soret (B) and the α-β (Q) bands. The observed trends in band frequencies can nevertheless be readily understood within the four-orbital model of Gouterman. Interpretation of band intensities is less clear.

Original languageEnglish (US)
Pages (from-to)4235-4240
Number of pages6
JournalJournal of the American Chemical Society
Issue number15
StatePublished - Jan 1 1984


ASJC Scopus subject areas

  • Catalysis
  • Chemistry(all)
  • Biochemistry
  • Colloid and Surface Chemistry

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