title: Influence of the 5f Orbitals on the Bonding and Reactivity in Organoactinides: Experimental and Computational Studies on a Uranium Metallacyclopropene.
abstract: The synthesis, structure, and reactivity of a uranium metallacyclopropene were comprehensively studied. Reduction of (η(5)-C5Me5)2UCl2 (1) with potassium graphite (KC8) in the presence of bis(trimethylsilyl)acetylene (Me3SiC≡CSiMe3) allows the first stable uranium metallacyclopropene (η(5)-C5Me5)2U[η(2)-C2(SiMe3)2] (2) to be isolated. Magnetic susceptibility data confirm that 2 is a U(IV) complex, and density functional theory (DFT) studies indicate substantial 5f orbital contributions to the bonding of the metallacyclopropene U-(η(2)-C═C) moiety, leading to more covalent bonds between the (η(5)-C5Me5)2U(2+) and [η(2)-C2(SiMe3)2](2-) fragments than those in the related Th(IV) compound. Consequently, very different reactivity patterns emerge, e.g., 2 can act as a source for the (η(5)-C5Me5)2U(II) fragment when reacted with alkynes and a variety of heterounsaturated molecules such as imines, bipy, carbodiimide, organic azides, hydrazine, and azo derivatives.
authors.affiliation: Department of Chemistry, Beijing Normal University , Beijing 100875, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Department of Chemistry, Beijing Normal University , Beijing 100875, China.
authors.forename: Guohua
authors.initials: G
authors.lastname: Hou
authors.affiliation: Department of Chemistry, Beijing Normal University , Beijing 100875, China.
authors.forename: Guofu
authors.initials: G
authors.lastname: Zi
authors.affiliation: Department of Chemistry, Beijing Normal University , Beijing 100875, China.
authors.forename: Wanjian
authors.initials: W
authors.lastname: Ding
authors.affiliation: Institut für Anorganische und Analytische Chemie, Technische Universität Braunschweig , Hagenring 30, 38106 Braunschweig, Germany.
authors.forename: Marc D
authors.initials: MD
authors.lastname: Walter