title: A Homoleptic Uranium(III) Tris(aryl) Complex.
abstract: The reaction of 3 equiv of Li-C6H3-2,6-(C6H4-4-tBu)2(Terph-Li) with UI3(1,4-dioxane)1.5led to the formation of the homoleptic uranium(III) tris(aryl) complex (Terph)3U (1). The U-C bonds are reactive: treatment with excessiPrN═C═NiPr yielded the double-insertion product [TerphC(NiPr)2]2U(Terph) (2). Complexes 1 and 2 were characterized by X-ray crystallography, which showed that the U-C bond length in 2 (2.624(4) Å) is ∼0.1 Å longer than the average U-C bond length in 1 (2.522(2) Å). Thermal decomposition of 1 yielded Terph-H as the only identifiable product; the process is unimolecular with activation parameters ΔH⧧= 21.5 ± 0.3 kcal/mol and ΔS⧧= -7.5 ± 0.8 cal·mol-1K-1, consistent with intramolecular proton abstraction. The protonolysis chemistry of 1 was also explored, which led to the uranium(IV) alkoxide complex U(OCPh3)4(DME) (3·DME).
authors.affiliation: Department of Chemistry, University of California, Berkeley , and Chemical Sciences Division, Lawrence Berkeley Laboratory, Berkeley, California 94720, United States.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Boreen
authors.affiliation: Department of Chemistry, University of California, Berkeley , and Chemical Sciences Division, Lawrence Berkeley Laboratory, Berkeley, California 94720, United States.
authors.forename: Bernard F
authors.initials: BF
authors.lastname: Parker
authors.affiliation: Department of Chemistry, University of California, Berkeley , and Chemical Sciences Division, Lawrence Berkeley Laboratory, Berkeley, California 94720, United States.
authors.forename: Trevor D
authors.initials: TD
authors.lastname: Lohrey
authors.affiliation: Department of Chemistry, University of California, Berkeley , and Chemical Sciences Division, Lawrence Berkeley Laboratory, Berkeley, California 94720, United States.
authors.forename: John
authors.initials: J
authors.lastname: Arnold