Fixation of Zinc(II) Ion to Dioxygen in a Highly Deformed Porphyrin: Implications for the Oxygen Carrier Mechanism of Distorted Heme

Org Lett. 2015 Aug 21;17(16):4078-81. doi: 10.1021/acs.orglett.5b02010. Epub 2015 Aug 13.

Abstract

Three saddle-type nonplanar zinc porphyrins strapped by two short alkyl linkers have been synthesized. The deformation induced by the linkers can cause a spectral red shift of >30 nm compared with the absorption maxima of regular porphyrins and can also regulate the electronic structure of the central zinc(II) ion. The zinc(II) ion then complexes and activates a free dioxygen to form a superoxide group ligand by enlarging the splitting of energy levels of d orbitals under strong core deformation. The fixation of dioxygen can be reasonably explained by the Dewar-Chatt-Duncanson model. These results indicate that this type of saddle porphyrin has the potential to be used as a new model system of heme.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Heme / chemistry*
  • Models, Molecular
  • Molecular Structure
  • Oxygen / chemistry*
  • Porphyrins / chemistry*
  • Zinc / chemistry*

Substances

  • Porphyrins
  • Heme
  • Zinc
  • Oxygen