Associative detachment of rubidium hydroxide

TL;DR

This study investigates the associative detachment process of rubidium hydroxide by calculating molecular structures, energies, and reaction pathways, revealing vibrational state-dependent rates that could enable control of the reaction.

Contribution

The paper provides detailed computational analysis of RbOH and its anion, identifying charge transfer pathways and quantifying associative detachment rates based on vibrational states.

Findings

Associative detachment rate is >2×10^{-9} cm^3s^{-1} for vibrational levels v≥2.

No significant detachment rate for vibrational levels v=0 and 1.

Vibrational excitation can be used to control the detachment process.

Abstract

We performed calculations of the optimized structure, harmonic vibrational frequencies and dissociation energies of RbOH and its anion, and investigate the interactions between Rb and OH$^-$ leading to possible associative detachment pathways. The electron affinity of RbOH was computed to be 0.2890 eV, with a bond energy of Rb+OH$^-$ half that of Rb+OH. To determine other possible charge loss pathways, the Rb+OH and Rb+OH$^-$ dissociation curves were computed using couple cluster methods along all possible collisional angles. An adiabatic curve crossing between the neutral and charged molecule was found at the inner wall of the molecular potential curve for linear geometries. Associative detachment rates were estimated using the Langevin ion capture cross-section for hydroxide. We find for $v\ge 2$ an associative detachment rate of $>2\times 10^{-9}$ cm$^3$s$^{-1}$, while for $v=0$ and 1 no appreciable rate exists. This strong dependence on vibrational level suggests the ability to control the associative detachment rate directly.