Anionic Clusters Produced in Low-Energy Electron Irradiation of Methanol Liquid

In the low-energy electron impacts with a liquid beam of methanol, we detect the anionic yields using a linear time-of-flight mass spectrometer. With help of quantum chemistry calculations, we further identify these anionic products as the hydrogen-bonding clusters, i.e., CH₃OH·CH₃O⁻ and CH₃OH·CH₃OH·CH₃O⁻, and their singly occupied molecular orbitals show the valence-bound feature. In contrast, CH₃OH·CH₃OH⁻ and CH₃OH·CH₃OH·CH₃OH⁻ are unfavored in energetics with respect to the dehydrogenated ones, although they also correspond to the minima on the potential energy surfaces. Furthermore, the singly occupied molecular orbitals of CH₃OH·CH₃OH⁻ and CH₃OH·CH₃OH·CH₃OH⁻ indicate the typical feature of aqueous-solvated electron.