Strong correlations in actinide redox reactions

Abstract

Reduction-oxidation (redox) reactions of the redox couples An(VI)/An(V), An(V)/An(IV), and An(IV)/An(III), where An is an element in the family of early actinides (U, Np, and Pu), as well as Am(VI)/Am(V) and Am(V)/Am(III), are modeled by combining density functional theory with a generalized Anderson impurity model that accounts for the strong correlations between the 5f electrons. Diagonalization of the Anderson impurity model yields improved estimates for the redox potentials and the propensity of the actinide complexes to disproportionate.

Computational Redox Potential Predictions: Applications to Inorganic and Organic Aqueous Complexes, and Complexes Adsorbed to Mineral Surfaces

“…Moreover, the use of SC PPs for An (U, Np, and Pu) atoms were found to predict better properties such as vibrational frequencies and thermochemistry. All electron (AE) and zeroth order regular approximation (ZORA) methods have also predicted similar reduction potentials like the SC PPs relativistic methods for these actinyl aqua complexes [137,139,141].…”

“…Except the protactinium (Pa), uranium (U) and thorium (Th) elements, the remaining elements are manmade elements. The interests to study the redox chemistry of actinides have been growing over the years [16,45,58,59,83,[136][137][138][139][140]. The reason for this high emphasis is that these elements, in particular U, Np, and Pu, are used in nuclear reactors for power generation.…”

“…The following overall redox reactions including the SHE reference were employed to calculate the actinyl(V) to An(IV) and An(IV) to An(III) redox potentials [139].…”

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

“…The advantage of studying actinides using computational techniques is safe and provides more precise understanding before tackling tedious experimental tasks and even can able to guide experimentalists. In recent years, computational approaches have been employed as important tools to predict several essential properties of actinides relevant to nuclear waste management and safe disposal such as electronic structure and bonding 5 , hydration [6][7][8] , speciation [9][10][11][12] , redox chemistry [13][14][15][16][17][18][19][20] , spectral properties [21][22][23][24] , reaction mechanisms [25][26][27][28][29][30][31][32][33] and electron transfer reactions. [34][35][36][37][38][39][40][41] Penta-valent uranyl(V) ions are unstable and readily disproportionate to form U(IV) and uranyl(VI) complexes in aqueous solution.…”

Systematic analysis of structural and topological properties: new insights into PuO2(H2O)n2+(n = 1–6) complexes in the gas phase

“…7 Therefore, the interactions of plutonyl with other ligand molecules have attracted considerable attention. [8][9][10][11][12][13][14][15][16][17][18] In particular, researches have focused on the interaction of plutonyl with H 2 O molecules, which is a major issue in secure nuclear storage, because H 2 O plays a catalytic role in plutonium corrosion. 19,20 Theoretical research in this area is more common than experimental; this may be due to the high activity and radioactivity which causes difficulties for experimental studies.…”