title: A linear, O-coordinated eta1-CO2 bound to uranium.
abstract: The electron-rich, six-coordinate tris-aryloxide uranium(III) complex [((AdArO)3tacn)U(III)] [where (AdArOH)3tacn = 1,4,7-tris(3-adamantyl-5-tert-butyl-2-hydroxybenzyl)1,4,7-triazacyclononane] reacts rapidly with CO2 to yield [((AdArO)3tacn)U(IV)(CO2)], a complex in which the CO(2) ligand is linearly coordinated to the metal through its oxygen atom (eta1-OCO). The latter complex has been crystallographically and spectroscopically characterized. The inequivalent O-C-O bond lengths [1.122 angstroms (A) for the O-C bond adjacent to uranium and 1.277 A for the other], considered together with magnetization data and electronic and vibrational spectra, support the following bonding model: U(IV)=O=C*-O- <--> U(IV)-OC-O-. In these charge-separated resonance structures, the uranium center is oxidized to uranium(IV) and the CO2 ligand reduced by one electron.
authors.affiliation: Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, MC 0358, La Jolla, CA 92093, USA.
authors.forename: Ingrid
authors.initials: I
authors.lastname: Castro-Rodriguez
authors.forename: Hidetaka
authors.initials: H
authors.lastname: Nakai
authors.forename: Lev N
authors.initials: LN
authors.lastname: Zakharov
authors.forename: Arnold L
authors.initials: AL
authors.lastname: Rheingold
authors.forename: Karsten
authors.initials: K
authors.lastname: Meyer
mesh_terms: D002245:Carbon Dioxide / Q000737:chemistry*; D003461:Crystallography; D004583:Electrons; D057927:Hydrophobic and Hydrophilic Interactions; D008024:Ligands; D008280:Magnetics; D008958:Models, Molecular; D015394:Molecular Structure; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry*; D013057:Spectrum Analysis; D013696:Temperature; D014501:Uranium / Q000737:chemistry*; D014965:X-Rays
chemical_list: D008024:Ligands; D002245:Carbon Dioxide; D014501:Uranium; D010100:Oxygen