Triplet state electron paramagnetic resonance studies of zinc porphyrins and zinc-substituted hemoglobins and myoglobins. Academic Article uri icon


  • Electron paramagnetic resonance studies of photoexcited, five-coordinate zinc mesoporphyrin IX (ZnMesoPor) and protoporphyrin IX (ZnPor) complexes have demonstrated the importance of vinyl-group conjugation and axial-ligand π bonding in determining the properties of the lowest metalloporphyrin triplet state. The conformational properties of that state have also been discussed. In addition, ZnPor and ZnMesoPor have been incorporated into the heme crevice of apohemoglobin and apomyoglobin, and the triplet state properties of these zinc-substituted hemoproteins have been studied. Differences between the porphyrin-protein interaction in T-state hemoglobin and myoglobin (an analog for R-state hemoglobin), and chain differences within the T state, are observed and discussed. © 1975, American Chemical Society. All rights reserved.

published proceedings

  • J Am Chem Soc

author list (cited authors)

  • Hoffman, B. M

citation count

  • 45

complete list of authors

  • Hoffman, BM

publication date

  • April 1975