Generalized molecular orbital calculations on transition-metal dioxygen complexes. Models for iron and cobalt porphyrins Academic Article uri icon


  • Generalized molecular orbital calculations with configuration interaction are reported for the dioxygen complexes of Co and Fe. The other ligands include a model ligand to represent the porphyrin ring system and a trans ammonia. The Co-O2 system is best described as a superoxide complex, Co3+-O2-, with the unpaired electron in a nearly pure πg O2 orbital. The Fe-02 system is best described as a singlet dioxygen, O2 (1Δg)σ donating to and x accepting from an Fe2+. All of the experimental results for both systems can be rationalized with these descriptions. The calculations predict a low-lying triplet state for the Fe02 system, but not low enough in energy to explain the recently reported paramagnetism of hemoglobin. © 1984, American Chemical Society. All rights reserved.

author list (cited authors)

  • Newton, J. E., & Hall, M. B.

citation count

  • 51

publication date

  • December 1984