Publications by authors named "Bogdan C Ibanescu"

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.

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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.

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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.

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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.

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