Reaction Pathways of Water Dimer Following Single Ionization

TL;DR

This study investigates the ionization-induced reaction pathways of water dimer, revealing detailed ion yields, energetics, and six newly identified pathways, providing insights into fundamental atmospheric and chemical processes.

Contribution

It presents the first comprehensive analysis of all ion products and reaction pathways of water dimer after single ionization, including six novel pathways and isotope effects.

Findings

Identified all ion products of water dimer ionization.

Revealed six new reaction pathways.

Observed significant isotope effects.

Abstract

Water dimer $(\text{H}_2\text{O})_2$ -- a vital component of the earth's atmosphere -- is an important prototypical hydrogen-bonded system. It provides direct insight into fundamental chemical and biochemical processes, e.g., proton transfer and ionic supramolecular dynamics occurring in astro- and atmospheric chemistry. Exploiting a purified molecular beam of water dimer and multi-mass ion imaging, we report the simultaneous detection of all generated ion products of $(\text{H}_2\text{O})^{+}_2$-fragmentation following single ionization. Detailed information about ion yields and reaction energetics of 13 ion-radical pathways, 6 of which are new, of $(\text{H}_2\text{O})^{+}_2$ are presented, including strong ${}^{18}\text{O}$-isotope effects.