Dissociative electron attachment to HNO3 and its hydrates: energy-selective electron-induced chemistry

2019 ◽  
Vol 21 (17) ◽  
pp. 8691-8697 ◽  
Author(s):  
Jozef Lengyel ◽  
Juraj Fedor ◽  
Michal Fárník
Keyword(s):  
Nitric Acid ◽  
Electron Energy ◽  
Water Clusters ◽  
Electron Attachment ◽  
Acid Water ◽  
Dissociative Electron Attachment

The chemistry of mixed nitric acid–water clusters triggered by electron attachment depends on clustering and the electron energy.

IR photon enhanced dissociative electron attachment to SF6: Dependence on photon, vibrational, and electron energy

2006 ◽  
Vol 329 (1-3) ◽  
pp. 148-162 ◽  
Author(s):  
M. Braun ◽  
F. Gruber ◽  
M.-W. Ruf ◽  
S.V.K. Kumar ◽  
E. Illenberger ◽  
...  
Keyword(s):  
Electron Energy ◽  
Electron Attachment ◽  
Dissociative Electron Attachment

scholarly journals Electron-induced chemistry in microhydrated sulfuric acid clusters

2017 ◽  
Vol 17 (22) ◽  
pp. 14171-14180 ◽  
Author(s):  
Jozef Lengyel ◽  
Andriy Pysanenko ◽  
Michal Fárník
Keyword(s):  
Sulfuric Acid ◽  
Density Functional ◽  
Water Clusters ◽  
Electron Attachment ◽  
Negative Ions ◽  
Ion Pair ◽  
Acid Water ◽  
Negative Ion ◽  
Water Molecules ◽  
Beam Experiment

Abstract. We investigate the mixed sulfuric acid–water clusters in a molecular beam experiment with electron attachment and negative ion mass spectrometry and complement the experiment by density functional theory (DFT) calculations. The microhydration of (H2SO4)m(H2O)n clusters is controlled by the expansion conditions, and the electron attachment yields the main cluster ion series (H2SO4)m(H2O)nHSO4− and (H2O)nH2SO4−. The mass spectra provide an experimental evidence for the onset of the ionic dissociation of sulfuric acid and ion-pair (HSO4−  ⋅  ⋅  ⋅  H3O+) formation in the neutral H2SO4(H2O)n clusters with n ≥ 5 water molecules, in excellent agreement with the theoretical predictions. In the clusters with two sulfuric acid molecules (H2SO4)2(H2O)n this process starts as early as n ≥ 2 water molecules. The (H2SO4)m(H2O)nHSO4− clusters are formed after the dissociative electron attachment to the clusters containing the (HSO4−  ⋅  ⋅  ⋅  H3O+) ion-pair structure, which leads to the electron recombination with the H3O+ moiety generating H2O molecule and the H-atom dissociation from the cluster. The (H2O)nH2SO4− cluster ions point to an efficient caging of the H atom by the surrounding water molecules. The electron-energy dependencies exhibit an efficient electron attachment at low electron energies below 3 eV, and no resonances above this energy, for all the measured mass peaks. This shows that in the atmospheric chemistry only the low-energy electrons can be efficiently captured by the sulfuric acid–water clusters and converted into the negative ions. Possible atmospheric consequences of the acidic dissociation in the clusters and the electron attachment to the sulfuric acid–water aerosols are discussed.

scholarly journals Direct observation of long-lived cyanide anions in superexcited states

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Xiao-Fei Gao ◽  
Jing-Chen Xie ◽  
Hao Li ◽  
Xin Meng ◽  
Yong Wu ◽  
...  
Keyword(s):  
Direct Observation ◽  
Electron Attachment ◽  
Planetary Atmosphere ◽  
Interstellar Space ◽  
Dissociative Electron Attachment ◽  
Circumstellar Envelopes ◽  
Vibrational States ◽  
Cyanide Anion ◽  
Exceptional Stability ◽  
Electronic Ground

AbstractThe cyanide anion (CN−) has been identified in cometary coma, interstellar medium, planetary atmosphere and circumstellar envelopes, but its origin and abundance are still disputed. An isolated CN− is stabilized in the vibrational states up to ν = 17 of the electronic ground-state 1Σ+, but it is not thought to survive in the electronic or vibrational states above the electron autodetachment threshold, namely, in superexcited states. Here we report the direct observation of long-lived CN− yields of the dissociative electron attachment to cyanogen bromide (BrCN), and confirm that some of the CN− yields are distributed in the superexcited vibrational states ν ≥ 18 (1Σ+) or the superexcited electronic states 3Σ+ and 3Π. The triplet state can be accessed directly in the impulsive dissociation of BrCN− or by an intersystem transition from the superexcited vibrational states of CN−. The exceptional stability of CN− in the superexcited states profoundly influences its abundance and is potentially related to the production of other compounds in interstellar space.

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