Structural changes of uranyl moiety with reduction from U(VI) to U(V)

Abstract

Summary Redox behavior of U VI O 2 (dbm) 2 DMSO (dbm = dibenzoylmethanate, DMSO = dimethyl sulfoxide, 2 VI ) and structural properties of U V O 2 + complexes have been investigated with cyclic voltammetry and IR spectroelectrochemical technique, respectively. As a result, it was confirmed that 2 VI is quasi-reversibly reduced to [U V O 2 (dbm) 2 DMSO] - ( 2 V ) without any successive reactions, and that 2 V is stable in DMSO. The formal potential for the redox couple, 2 V / 2 VI , is -1.362 V vs . the ferrocene/ferrocenium ion redox couple. The IR spectra measured at various applied potentials show a shift of the peak due to the asymmetric stretching (ν 3 ) of O=U=O from 906 to 775 cm -1 with the reduction from 2 VI to 2 V . From the ν 3 peak positions, U=O distances of 2 V and 2 VI were estimated as 1.82 and 1.76 Å by Badger´s rule.