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

Dissociative electron attachment spectra of 20 saturated compounds containing ether and hydroxyl groups are presented. Two groups of fragmentation processes are identified: (i) one or two bands mediated by shape resonances in the 1-5 eV range and (ii) three bands (often overlapping) in the 5-12 eV range, assigned to Feshbach resonances with a hole in either the oxygen 'nonbonding' orbitals n(O) or [symbol: see text], or in one of the available sigma orbitals. The main result of this paper is the discovery of unexpected selectivity in the cleavage of C-O bonds in asymmetric ethers, R1-O-R2, within the range of the sigma-Feshbach resonances, where the loss of a neutral alkyl group, R1, peaks at a given energy (9.

A dramatic difference between the electron-driven dissociation of alcohols and ethers and its relation to Rydberg states.

A difference was observed in the reactivity of alcohols and ethers toward free electrons. Whereas the lowest core-excited state of the negative ion-a 2(n,3s2) Feshbach resonance-of the alcohols readily dissociates by losing a hydrogen atom, ethers show no observable signal from this resonance. This difference in reactivity has a parallel in the anomalous shapes and energies of the parent states of the Feshbach resonances, the 1(n,3s) Rydberg states of the neutral alcohols.

Cleavage of the ether bond by electron impact: differences between linear ethers and tetrahydrofuran.

Dissociative electron attachment (DEA) to diethyl ether yielded primarily the C(2)H(5)O(-) ion, with a strong Feshbach resonance band at 9.1 eV and a weaker shape resonance band at 3.89 eV.

Electron-induced chemistry of alcohols.

We studied dissociative electron attachment to a series of compounds with one or two hydroxyl groups. For the monoalcohols we found, apart from the known fragmentations in the 6-12 eV range proceeding via Feshbach resonances, also new weaker processes at lower energies, around 3 eV. They have a steep onset at the dissociation threshold and show a dramatic D/H isotope effect.