Water mediated Electron Attachment to Nucleobases: Surface-bound vs Bulk Solvated Electrons

TL;DR

This study explores how water molecules influence electron attachment to uracil, revealing that bulk water accelerates electron transfer and stabilizes the resulting anion, with similar long-term behavior for surface-bound and bulk solvated electrons.

Contribution

It provides detailed insights into the dynamics of electron transfer from water to uracil, highlighting the role of solvation and environment in the process.

Findings

Bulk water accelerates electron attachment to uracil.

Water stabilizes uracil anion via hydrogen bonding.

Surface-bound and bulk solvated electrons lead to similar long-term anions.

Abstract

We have investigated the electron attachment dynamics of uracil in water using accurate wave-function and QM/MM methods. The initial electron attached state is found to be localized on the water and mixing of electronic and nuclear degrees of freedom leads to the transfer of electron from the water to the uracil. The water molecules around the uracil stabilize the uracil bound anion by creating an extensive hydrogen-bonding network. The presence of the bulk water environment accelerates the rate of electron attachment to uracil and the complete electron transfer from water to the uracil happens at a picosecond time scale. The degree of solvation of the aqueous electron can lead to a difference in the initial stabilization of the uracil bound anion but at a longer time scale the anion formed due to the attachment of both surface-bound and bulk solvated electrons behaves similarly.