Selective cleavage of the C-O bonds in alcohols and asymmetric ethers by dissociative electron attachment

We present a comparative study of dissociative electron attachment for 20 saturated compounds containing ether and hydroxyl groups. We have discovered an unexpected case of selectivity for the cleavage of the C-O bonds in asymmetrical ethers R1-O-R2, within the range of the σ-Feshbach resonances, where a neutral alkyl group R1 is lost at a given energy, independent of R2. This empirical rule indicates that the excitation of Feshbach resonances responsible for the fragmentation is spatially localized on one or the other alkyl group. A number of other observations are also presented.