title: Enhancement of C-H Oxidizing Ability in Co-O2Complexes through an Isolated Heterobimetallic Oxo Intermediate.
abstract: The characterization of intermediates formed through the reaction of transition-metal complexes with dioxygen (O2) is important for understanding oxidation in biological and synthetic processes. Here, the reaction of the diketiminate-supported cobalt(I) complex LtBuCo with O2gives a rare example of a side-on dioxygen complex of cobalt. Structural, spectroscopic, and computational data are most consistent with its assignment as a cobalt(III)-peroxo complex. Treatment of LtBuCo(O2) with low-valent Fe and Co diketiminate complexes affords isolable oxo species with M2O2"diamond" cores, including the first example of a crystallographically characterized heterobimetallic bis(μ-oxo) complex of two transition metals. The bimetallic species are capable of cleaving C-H bonds in the supporting ligands, and kinetic studies show that the Fe/Co heterobimetallic species activates C-H bonds much more rapidly than the Co/Co homobimetallic analogue. Thus heterobimetallic oxo intermediates provide a promising route for enhancing the rates of oxidation reactions.
authors.affiliation: Department of Chemistry, Yale University, 225 Prospect St., New Haven, CT, 06511, USA.
authors.forename: Daniel E
authors.initials: DE
authors.lastname: DeRosha
authors.affiliation: Department of Chemistry, Yale University, 225 Prospect St., New Haven, CT, 06511, USA.
authors.forename: Brandon Q
authors.initials: BQ
authors.lastname: Mercado
authors.affiliation: Department of Chemistry and Biochemistry, North Dakota State University, PO Box 6050, Fargo, ND, 58108, USA.
authors.forename: Gudrun
authors.initials: G
authors.lastname: Lukat-Rodgers
authors.affiliation: Department of Chemistry and Biochemistry, North Dakota State University, PO Box 6050, Fargo, ND, 58108, USA.
authors.forename: Kenton R
authors.initials: KR
authors.lastname: Rodgers
authors.affiliation: Department of Chemistry, Yale University, 225 Prospect St., New Haven, CT, 06511, USA.
authors.forename: Patrick L
authors.identifier: 0000-0002-2883-2031
authors.initials: PL
authors.lastname: Holland
mesh_terms: D003035:Cobalt / Q000737:chemistry*; D008968:Molecular Conformation; D009942:Organometallic Compounds / Q000737:chemistry* / Q000302:isolation & purification; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry*
chemical_list: D009942:Organometallic Compounds; D003035:Cobalt; D010100:Oxygen
keywords: cobalt; heterobimetallic complexes; iron; oxygen activation