Sneaking Up On The Criegee Intermediate From Below: Predicted Photoelectron Spectrum Of The CH_2OO^- Anion And W3-F12 Electron Affinity Of CH_2OO

TL;DR

This study uses high-level ab initio calculations to predict the electron affinity and photoelectron spectrum of the CH2OO molecule and its anion, revealing key geometric differences and vibrational features.

Contribution

The paper provides the first high-accuracy predictions of the electron affinity and photoelectron spectrum of CH2OO and its anion using the W3-F12 protocol.

Findings

Electron affinity of CH2OO is 0.567 eV.

Barrier height for dissociation is 16.5 kJ mol$^{-1}$.

Predicted spectrum shows vibrational progressions due to geometric differences.

Abstract

High level ab initio calculations were undertaken on the CH$_2$OO anion and neutral species to predict the electron affinity and anion photoelectron spectrum. The electron affinity of CH$_2$OO, 0.567 eV, and barrier height for dissociation of CH$_2$OO$^-$ to O$^-$ and CH$_2$O, 16.5 kJ mol$^{-1}$, are obtained by means of the W3-F12 thermochemical protocol. Two major geometric differences between the anion and neutral, being the dihedral angle of the terminal hydrogen atoms with respect to C-O-O plane, and the O-O bond length, are reflected in the predicted spectrum as pronounced vibrational progressions.