New Chemistry from an Old Reagent: Mono- and Dinuclear Macrocyclic Uranium(Ⅲ) Complexes from [U(BH_4)_3(THF)_2]

摘要

A new robust and high-yielding synthesis of the valuable U~Ⅲ synthon [U(BH_4)_3(THF)_2] is reported. Reactivity in ligand exchange reactions is found to contrast significantly to that of uranium triiodide. This is exemplified by the synthesis and characterization of azamacrocyclic U~Ⅲ complexes, including mononuclear [U(BH_4)(L)] and dinuclear [Li(THF)_4][{U(BH_4)}_2(μ-BH_4)(L~(Me))] and [Na(THF)_4][{U(BH_4)}_2(μ-BH_4)(L~A)-(THF)_2]. The structures of all complexes have been determined by single-crystal X-ray diffraction and display two new U~Ⅲ_2(BH_4)_3 motifs.