title: Hydrated Electron Transfer to Nucleobases in Aqueous Solutions Revealed by Ab Initio Molecular Dynamics Simulations.
abstract: We present an ab initio molecular dynamics (AIMD) simulation study into the transfer dynamics of an excess electron from its cavity-shaped hydrated electron state to a hydrated nucleobase (NB)-bound state. In contrast to the traditional view that electron localization at NBs (G/A/C/T), which is the first step for electron-induced DNA damage, is related only to dry or prehydrated electrons, and a fully hydrated electron no longer transfers to NBs, our AIMD simulations indicate that a fully hydrated electron can still transfer to NBs. We monitored the transfer dynamics of fully hydrated electrons towards hydrated NBs in aqueous solutions by using AIMD simulations and found that due to solution-structure fluctuation and attraction of NBs, a fully hydrated electron can transfer to a NB gradually over time. Concurrently, the hydrated electron cavity gradually reorganizes, distorts, and even breaks. The transfer could be completed in about 120-200 fs in four aqueous NB solutions, depending on the electron-binding ability of hydrated NBs and the structural fluctuation of the solution. The transferring electron resides in the π*-type lowest unoccupied molecular orbital of the NB, which leads to a hydrated NB anion. Clearly, the observed transfer of hydrated electrons can be attributed to the strong electron-binding ability of hydrated NBs over the hydrated electron cavity, which is the driving force, and the transfer dynamics is structure-fluctuation controlled. This work provides new insights into the evolution dynamics of hydrated electrons and provides some helpful information for understanding the DNA-damage mechanism in solution.
authors.affiliation: School of Chemistry and Chemical Engineering, Institute of Theoretical Chemistry, Shandong University, Jinan, 250100 (P. R. China).|Shandong Collegial Key Laboratory of Biotechnology and Utilization of Biological Resources, College of Life Science, Dezhou University, Dezhou 253023 (P. R. China).
authors.forename: Jing
authors.initials: J
authors.lastname: Zhao
authors.affiliation: School of Chemistry and Chemical Engineering, Institute of Theoretical Chemistry, Shandong University, Jinan, 250100 (P. R. China).
authors.forename: Mei
authors.initials: M
authors.lastname: Wang
authors.affiliation: Shandong Collegial Key Laboratory of Biotechnology and Utilization of Biological Resources, College of Life Science, Dezhou University, Dezhou 253023 (P. R. China).
authors.forename: Aiyun
authors.initials: A
authors.lastname: Fu
authors.affiliation: School of Chemistry and Chemical Engineering, Institute of Theoretical Chemistry, Shandong University, Jinan, 250100 (P. R. China).
authors.forename: Hongfang
authors.initials: H
authors.lastname: Yang
authors.affiliation: School of Chemistry and Chemical Engineering, Institute of Theoretical Chemistry, Shandong University, Jinan, 250100 (P. R. China). byx@sdu.edu.cn.
authors.forename: Yuxiang
authors.initials: Y
authors.lastname: Bu
mesh_terms: D004579:Electron Transport; D004583:Electrons; D006860:Hydrogen Bonding; D056004:Molecular Dynamics Simulation; D009705:Nucleosides / Q000737:chemistry*; D011789:Quantum Theory; D014867:Water / Q000737:chemistry
chemical_list: D009705:Nucleosides; D014867:Water
keywords: ab initio calculations; electron transfer; hydrated electrons; nucleobases; valence anions