Rate theory on water exchange in aqueous uranyl ion

Journal Article · Wed Mar 01 00:00:00 EST 2017 · Chemical Physics Letters

DOI:https://doi.org/10.1016/j.cplett.2017.01.020· OSTI ID:1361954

Dang, Liem X.; Vo, Quynh N.; Nilsson, Mikael; Nguyen, Hung D.

We report one of the first simulations using a classical rate theory approach to predict the mechanism of the exchange process between water and aqueous uranyl ions. Using our water and ion-water polarizable force fields and molecular dynamics techniques, we computed the potentials of mean force for the uranyl ion-water pair as the function of pressures at ambient temperature. Subsequently, these simulated potentials of mean force were used to calculate rate constants using the transition rate theory; the time dependent transmission coefficients were also examined using the reactive flux method and Grote-Hynes treatments of the dynamic response of the solvent. The computed activation volumes using transition rate theory and the corrected rate constants are positive, thus the mechanism of this particular water-exchange is a dissociative process. We discuss our rate theory results and compare them with previously studies in which non-polarizable force fields were used. This work was supported by the US Department of Energy, Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences, and Biosciences. The calculations were carried out using computer resources provided by the Office of Basic Energy Sciences.

• Research Organization: Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1361954
• Report Number(s): PNNL-SA-122800; KC0301050
• Journal Information: Chemical Physics Letters, Vol. 671; ISSN 0009-2614
• Publisher: Elsevier
• Country of Publication: United States
• Language: English