Vibronic structure of alkoxy radicals via photoelectron spectroscopy Available to Purchase

Ultraviolet photoelectron spectra of $CH3O−,$ $CH3CH2O−,$ $(CH3)2CHO−,$ $(CH3)3CO−,$ as well as $CD3O−$ and $CD3CD2O−$ are presented, providing improved electron affinities and new information on vibronic coupling in the corresponding neutral radicals. Jahn-Teller vibronic transitions are assigned to e vibrational modes of $X̃ 2E$ $CH3O.$ The excitation energy of the $Ã 2A′$ state of $CH3CH2O$ with respect to the $X̃ 2A″$ state is observed directly at $355±10$ $cm−1.$ Vibronic coupling between these low-lying electronic states perturbs the observed vibronic levels. Features of the $(CH3)2CHO−$ photoelectron spectrum are assigned. The splitting between the $X̃ 2A′$ and $Ã 2A″$ states of $(CH3)2CHO$ is determined to be $1225±65$ $cm−1.$ Significant vibronic coupling is not observed in $(CH3)2CHO.$ Vibrational assignments are made for the spectral features of $(CH3)3CO$ and no Jahn-Teller effects are observed directly. Electron affinities (EAs) for the neutrals (RO) are (in eV); $EA(CH3O)=1.572±0.004;$ $EA(CD3O)=1.559±0.004;$ $EA(CH3CH2O)=1.712±0.004;$ $EA(CD3CD2O)=1.699±0.004;$ $EA((CH3)2CHO)=1.847±0.004;$ $EA((CH3)3CO)=1.909±0.004.$ Bond dissociation energies of ROH, $D300(RO–H),$ along with $ΔfH300(RO),$ $ΔfH300(RO−),$ and $ΔfH300(RO+)$ are derived.