摘要:
The cyclic voltammogram of UCl4 in THF, with NBu4BPh4 as the supporting electrolyte, exhibits three cathodic waves at - 2.0, - 2.50 and - 2.70 V (versus Ag/AgCl); they are irreversible and of the EC type, with the formation of U (IV) anions [U2Cl9](-) and [UCl5](-). This proceeds by chloride ion transfer reactions from the electrogenerated anionic U(III) species. These reduction pathways were confirmed by electrochemical studies of the independently synthesized complexes [NBu4][U2Cl9]. 2.5THF (1), [NBu4][UCl5(THF)] (2) and [UCl3(THF)(2)][BPh4] (4). Complex 2 was characterized by its crystal structure; the anion displays an octahedral geometry with U-Cl = 2.60(1) Angstrom (average) and U-O = 2.42(1) Angstrom. (C) 1998 Elsevier Science S.A. All rights reserved.