Research output: Contribution to journal › Article › peer-review
Resonance electron interaction with five-membered heterocyclic compounds : Vibrational Feshbach resonances and hydrogen-atom stripping. / Pshenichnyuk, Stanislav A.; Fabrikant, Ilya I.; Modelli, Alberto; Ptasińska, Sylwia; Komolov, Alexei S.
In: Physical Review A, Vol. 100, No. 1, 012708, 22.07.2019.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - Resonance electron interaction with five-membered heterocyclic compounds
T2 - Vibrational Feshbach resonances and hydrogen-atom stripping
AU - Pshenichnyuk, Stanislav A.
AU - Fabrikant, Ilya I.
AU - Modelli, Alberto
AU - Ptasińska, Sylwia
AU - Komolov, Alexei S.
PY - 2019/7/22
Y1 - 2019/7/22
N2 - Low-energy (0-15 eV) resonance electron attachment to a series of five-membered heterocyclic rings (isoxazole, imidazole, pyrazole, pyrrole, 1-methyl-, and 2-methylimidazole) is studied under gas-phase conditions by means of electron transmission spectroscopy and dissociative electron attachment spectroscopy (DEAS). Experimental spectral features are assigned on the basis of Hartree-Fock and density functional theory calculations. Sharp features, with a width of less than 0.1 eV, observed in the electron transmission spectra of imidazole, pyrazole, and pyrrole close to 0.45 eV, i.e., well below the energy of their lowest-lying π∗ shape resonances detected at 1.90, 1.87, and 2.33 eV, respectively, are associated with formation of negative ion states bound by long-range electron-molecule interactions. Effective range theory calculations which include both dipolar and polarization interactions support this interpretation. In addition to the general observation of cleavage of the N-H bond at incident electron energies close to 2 eV, elimination of as many as three hydrogen atoms from the molecular negative ions is detected at higher energies by DEAS with the only exception of methylated imidazoles. This complex process is associated with ring opening and formation of diatomic hydrogen as one of the neutral fragments, as indicated by the calculations to satisfy the energetic requirements. The present results are of importance for understanding the basic mechanisms of damages caused in living tissues by high-energy radiations.
AB - Low-energy (0-15 eV) resonance electron attachment to a series of five-membered heterocyclic rings (isoxazole, imidazole, pyrazole, pyrrole, 1-methyl-, and 2-methylimidazole) is studied under gas-phase conditions by means of electron transmission spectroscopy and dissociative electron attachment spectroscopy (DEAS). Experimental spectral features are assigned on the basis of Hartree-Fock and density functional theory calculations. Sharp features, with a width of less than 0.1 eV, observed in the electron transmission spectra of imidazole, pyrazole, and pyrrole close to 0.45 eV, i.e., well below the energy of their lowest-lying π∗ shape resonances detected at 1.90, 1.87, and 2.33 eV, respectively, are associated with formation of negative ion states bound by long-range electron-molecule interactions. Effective range theory calculations which include both dipolar and polarization interactions support this interpretation. In addition to the general observation of cleavage of the N-H bond at incident electron energies close to 2 eV, elimination of as many as three hydrogen atoms from the molecular negative ions is detected at higher energies by DEAS with the only exception of methylated imidazoles. This complex process is associated with ring opening and formation of diatomic hydrogen as one of the neutral fragments, as indicated by the calculations to satisfy the energetic requirements. The present results are of importance for understanding the basic mechanisms of damages caused in living tissues by high-energy radiations.
UR - http://www.scopus.com/inward/record.url?scp=85069821010&partnerID=8YFLogxK
U2 - 10.1103/PhysRevA.100.012708
DO - 10.1103/PhysRevA.100.012708
M3 - Article
AN - SCOPUS:85069821010
VL - 100
JO - Physical Review A - Atomic, Molecular, and Optical Physics
JF - Physical Review A - Atomic, Molecular, and Optical Physics
SN - 1050-2947
IS - 1
M1 - 012708
ER -
ID: 45418018