Electrochemical properties of uranium(VI) complexes with multidentate ligands in N,N-dimethylformamide

Synthesis and Characterization of a Water Stable Uranyl(V) Complex

“…The cyclic voltammetry data measured for 3 in pyridine solution (Figure ) showed the presence of two reversible redox events at E 1/2 = −1.25 V and at E 1/2 = −2.65 V that were assigned to the U­(VI)/U­(V) and U­(V)/U­(IV) couples respectively (no redox event is observed in the voltammogram of K 2 dpaea). The measured redox potential for the U­(VI)/U­(V) couple falls in the range (−0.93 – +1.82 V) of those reported for other uranyl­(V) complexes in organic media. ,, The voltammogram measured in 0.02 M HEPES buffered water solutions (pH = 7) at a glassy carbon working electrode shows a significant shift of the U­(VI)/U­(V) redox potentials with the U­(V)/U­(VI) oxidation event found at E = −0.16–0.00 V vs Ag/AgCl, and the U­(VI)/U­(V) reduction at E = −1.56 to −1.65 V vs Ag/AgCl depending on the scan speed. These values are very similar to those previously reported for the uranyl­(V)-carbonato complex ([UO 2 (CO 3 ) 3 ] 5– ) in Na 2 CO 3 at pH = 12 and a glassy carbon electrode (oxidation peak at 0–0.25 V and reduction peak at −1.5 to −1.7 V). , The U­(V)/U­(IV) redox event is not observable in water solution.…”

Density functional theory (DFT) calculations of VI/V reduction potentials of uranyl coordination complexes in non-aqueous solutions

“…The experimental reduction potentials for the investigated uranyl complexes in DMSO solution were taken from the references 44,54,[59][60][61][62][63][64][65][66] and for the DMF solution from the references. 54,62,[65][66][67][68] The experimental reduction potentials for the uranyl complexes explored in DCM solution were from Hayton et al [69][70][71][72] , Sessler et al 73 and from D.S.Royal's PhD thesis. 65 While the experimental reduction potentials for the uranyl complexes investigated in acetonitrile solution were obtained from the references 60,74,75,69 and for the uranyl complexes investigated in pyridine solutions from the references.…”

Electrochemical Studies on Uranyl(VI) Chloride Complexes in Ionic Liquid, 1-Butyl-3-methylimidazolium Chloride

“…32 (dmf = N,N-dimethylformamide) and UO 2 (acac) 2 dmf (acac = acetylacetonate) in dmf are 2:6 Â 10 À6 and 3:1 Â 10 À6 cm 2 s À1 at 23 C, respectively. [33][34][35][36] This difference is presumably due to the high viscosity of BMICl.…”