title: A two-state reactivity model explains unusual kinetic isotope effect patterns in C-H bond cleavage by nonheme oxoiron(IV) complexes.
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.
authors.affiliation: Department of Chemistry and Center for Metals in Biocatalysis, University of Minnesota, Minneapolis, MN 55455, USA.
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Klinker
authors.forename: Sason
authors.initials: S
authors.lastname: Shaik
authors.forename: Hajime
authors.initials: H
authors.lastname: Hirao
authors.forename: Lawrence
authors.initials: L
authors.lastname: Que
mesh_terms: D002384:Catalysis; D006838:Hydrocarbons / Q000737:chemistry / Q000378:metabolism; D007501:Iron / Q000737:chemistry / Q000378:metabolism*; D007553:Isotope Labeling; D007554:Isotopes / Q000737:chemistry / Q000378:metabolism*; D007700:Kinetics; D008956:Models, Chemical; D015394:Molecular Structure; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry / Q000378:metabolism*
chemical_list: D006838:Hydrocarbons; D007554:Isotopes; D007501:Iron; D010100:Oxygen