Electrochemical Properties of Bis(dicarbollide)uranium Dibromide.

The cyclic voltammogram of [(eta(5)-C(2)B(9)H(11))(2)UBr(2)].2[Li(THF(4))] shows the electrochemical generation of a uranium(III) species. Subsequent Na/Hg reduction of [(eta(5)-C(2)B(9)H(11))(2)UBr(2)].2[Li(THF(4))] leads to the new isolable uranium(III) species [(eta(5)-C(2)B(9)H(11))(2)UBr(THF)].2[Li(THF)(x)()] (x = 2-4). The green uranium(III) complex was characterized by NMR and elemental analysis and its structure determined by single-crystal X-ray crystallography. The coordination geometry around the dinegative uranium(III) moiety is pseudotetrahedral with two dicarbollide ligands, a bromide ligand, and a THF ligand. The electrochemical properties of the dicarbollide complex are discussed and compared to similar cyclopentadienyluranium complexes.