title: Synthesis of terminal monochalcogenide and dichalcogenide complexes of uranium using polychalcogenides, [E(n)]²⁻ (E = Te, n = 2; E = Se, n = 4), as chalcogen atom transfer reagents.
abstract: Reaction of KH with elemental tellurium, in the presence of 18-crown-6, results in the formation of the ditelluride, [K(18-crown-6)]2[Te2] (1), in good yield. Similarly, reaction of KH with elemental selenium, in the presence of 18-crown-6, results in the formation of [K(18-crown-6)]2[Se4] (4). Both 1 and 4 are capable of chalcogen atom transfer to U(III). For example, addition of 0.5 equiv or 1 equiv of [K(18-crown-6)]2[Te2] (1) to [U(NR2)3] (R = SiMe3) or [U(I)(NR2)3], respectively, results in the formation of the new U(IV) tellurides, [K(18-crown-6)][U(Te)(NR2)3] (2), and [K(18-crown-6)][U(η(2)-Te2)(NR2)3] (3), in moderate yields, while addition of 0.5 equiv of [K(18-crown-6)]2[Se4] (4) to [U(NR2)3] results in the formation of the U(IV) diselenide, [K(18-crown-6)][U(η(2)-Se2)(NR2)3] (5). Interestingly, 5 can be converted into the monoselenide [K(18-crown-6)][U(Se)(NR2)3] (6) via reaction with Ph3P.
authors.affiliation: Department of Chemistry and Biochemistry, University of California Santa Barbara , Santa Barbara California 93106, United States.
authors.forename: Danil E
authors.initials: DE
authors.lastname: Smiles
authors.forename: Guang
authors.initials: G
authors.lastname: Wu
authors.forename: Trevor W
authors.initials: TW
authors.lastname: Hayton