A two-state reactivity model explains unusual kinetic isotope effect patterns in C-H bond cleavage by nonheme oxoiron(IV) complexes

Angew Chem Int Ed Engl. 2009;48(7):1291-5. doi: 10.1002/anie.200804029.

Abstract

It's in the bond: The cleavage of C-H bonds by two related oxoiron(IV) complexes shows a range of kinetic isotope effect (KIE) values that exhibit an unusual dependence on the C-H bond strength. Large nonclassical KIEs are observed for bond strengths below 93 kcal mol(-1), while semiclassical values are found above this value (see graph, DHA = 9,10-dihydroanthracene). This nonintuitive behavior can be rationalized by invoking a two-state reactivity model.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Catalysis
  • Hydrocarbons / chemistry
  • Hydrocarbons / metabolism
  • Iron / chemistry
  • Iron / metabolism*
  • Isotope Labeling
  • Isotopes / chemistry
  • Isotopes / metabolism*
  • Kinetics
  • Models, Chemical
  • Molecular Structure
  • Oxidation-Reduction
  • Oxygen / chemistry
  • Oxygen / metabolism*

Substances

  • Hydrocarbons
  • Isotopes
  • Iron
  • Oxygen