scholarly journals Low-energy electron driven processes in ices: Synthesis reactions and surface functionalization

2008 ◽  
Vol 6 (1) ◽  
pp. 89-98
Author(s):  
I. Martin ◽  
L. Amiaud ◽  
R. Azria ◽  
A. Lafosse
Keyword(s):  
Electron Energy ◽  
Electron Attachment ◽  
Low Energy ◽  
Energy Electron ◽  
Molecular Anions ◽  
Resolution Electron ◽  
Decarboxylation Reaction ◽  
Low Energy Electrons ◽  
Low Energy Electron ◽  
Substrate Surfaces

Low-energy electrons, and subexcitation energy electrons in particular, have the ability to induce efficiently chemical modifications within condensed molecular films and at substrate surfaces. By taking advantage of the Dissociative Electron Attachment (DEA) process, which leads to selective bond cleavages, the induced reactivity can be controlled solely by the electron energy. Two illustrative examples of induced reactivity and substrate functionalization achieved by low-energy electron processing of condensed molecules studied by means of High Resolution Electron Energy Loss Spectroscopy (HREELS) are reviewed, and special interest is given to the possibility of proposing overall reaction mechanisms. The resonant decarboxylation reaction in condensed films of trifluoroacetic acid CF3COOH induced by electrons at ~1 eV involves the formation of the transient species [CF3COOH]#- and the further formation of CO2 by a concerted mechanism. Diamond substrate functionalization by CH2CN organic groups through Cdiam-C and Cdiam-N bonds is performed by 2 eV electron irradiation of condensed acetonitrile CH3CN and involves reactants formed by DEA, that are neutral radicals H? and molecular anions [H2CCN]-.

scholarly journals 5-Nitro-2,4-Dichloropyrimidine as an Universal Model for Low-Energy Electron Processes Relevant for Radiosensitization

2020 ◽  
Vol 21 (21) ◽  
pp. 8173
Author(s):  
Thomas F. M. Luxford ◽  
Stanislav A. Pshenichnyuk ◽  
Nail L. Asfandiarov ◽  
Tomáš Perečko ◽  
Martin Falk ◽  
...  
Keyword(s):  
Rational Design ◽  
Electron Attachment ◽  
Low Energy ◽  
Energy Electron ◽  
Model Molecule ◽  
Alternative Approach ◽  
Low Energy Electrons ◽  
Cluster Environment ◽  
Low Energy Electron ◽  
Low Solubility

We report experimental results of low-energy electron interactions with 5-nitro-2,4-dichloropyrimidine isolated in the gas phase and hydrated in a cluster environment. The molecule exhibits a very rare combination of many so far hypothesized low-energy electron induced mechanisms, which may be responsible for synergism in concurrent chemo-radiation therapy of cancer. In contrast to many previous efforts to design an ideal radiosensitizer based on one mode of action, the present model molecule presents an alternative approach, where several modes of action are combined. With respect to the processes induced by the low-energy electrons, this is not a trivial task because of strong bond specificity of the dissociative electron attachment reaction, as it is discussed in the present paper. Unfortunately, low solubility and high toxicity of the molecule, as obtained from preliminary MTT assay tests, do not enable further studies of its activity in real biological systems but it can advantageously serve as a model or a base for rational design of radiosensitizers.

Dissociation of methyl formate (HCOOCH3) molecules upon low-energy electron attachment

2018 ◽  
Vol 617 ◽  
pp. A102 ◽  
Author(s):  
L. Feketeová ◽  
A. Pelc ◽  
A. Ribar ◽  
S. E. Huber ◽  
S. Denifl
Keyword(s):  
Quantum Chemical Calculations ◽  
Electron Energy ◽  
Quantum Chemical ◽  
Methyl Formate ◽  
Experimental Studies ◽  
Electron Attachment ◽  
Low Energy ◽  
Energy Electron ◽  
Molecular Anion ◽  
Low Energy Electron

Context. The methyl formate molecule (HCOOCH3) is considered to be a key molecule in astrochemistry. The abundance of this molecule in space depends on the stability upon irradiation with particles like low-energy electrons. Aims. We have investigated the decomposition of the molecule upon electron capture in the electron energy range from about 0 eV up to 15 eV. All experimentally obtained fragmentation channels of the molecular anion were investigated by quantum chemical calculations. Methods. A high resolution electron monochromator coupled with quadrupole mass spectrometer was used for the present laboratory experiment. Quantum chemical calculations of the electron affinities of the generated fragments, the thermodynamic thresholds and the activation barriers for the associated reaction channels were carried out to complement the experimental studies. Results. Electron attachment is shown to be a purely dissociative process for this molecule and proceeds within two electron energy regions of about 1 eV to 4 eV and from 5 eV to 14 eV. In our experiment five anionic fragments with m/z (and possible stoichiometric structure) 59 (C2H3O2−), 58 (C2H2O2−), 45 (CHO2−) 31 (CH3O−), and 29 (CHO−) were detected. The most abundant anion fragments that are formed through dissociative electron attachment to methyl formate are the complementary anions CH3O− and CHO−, associated with the same single bond cleavage and different survival probability. Conclusions. The low-energy electron induced dissociation of methyl formate differs from its isomers acetic acid and glycolaldehyde, which leads to possible chemical selectivity in the chemical evolution.

scholarly journals Selective bond cleavage in RAFT agents promoted by low‐energy electron attachment

2021 ◽  
Author(s):  
Farhad Izadi ◽  
Eugene Arthur-Baidoo ◽  
Lisa T. Strover ◽  
Li-Juan Yu ◽  
Michelle L. Coote ◽  
...  
Keyword(s):  
Bond Cleavage ◽  
Electron Attachment ◽  
Low Energy ◽  
Energy Electron ◽  
Low Energy Electron

Tailoring Si(100) substrate surfaces for GaP growth by Ga deposition: A low-energy electron microscopy study

2015 ◽  
Vol 118 (5) ◽  
pp. 055701 ◽  
Author(s):  
Michael Rienäcker ◽  
Benjamin Borkenhagen ◽  
Gerhard Lilienkamp ◽  
Winfried Daum
Keyword(s):  
Electron Microscopy ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Low Energy ◽  
Energy Electron ◽  
Low Energy Electron ◽  
Substrate Surfaces

Low‐energy electron attachment to BCl3

1990 ◽  
Vol 67 (2) ◽  
pp. 675-678 ◽  
Author(s):  
Z. Lj. Petrović ◽  
W. C. Wang ◽  
M. Suto ◽  
J. C. Han ◽  
L. C. Lee
Keyword(s):  
Electron Attachment ◽  
Low Energy ◽  
Energy Electron ◽  
Low Energy Electron

scholarly journals Low energy electron energy-loss spectroscopy of CF3X (X=Cl,Br)

2007 ◽  
Vol 126 (2) ◽  
pp. 024303 ◽  
Author(s):  
M. Hoshino ◽  
K. Sunohara ◽  
C. Makochekanwa ◽  
L. Pichl ◽  
H. Cho ◽  
...  
Keyword(s):  
Energy Loss ◽  
Electron Energy ◽  
Electron Energy Loss Spectroscopy ◽  
Low Energy ◽  
Energy Electron ◽  
Low Energy Electron ◽  
Electron Energy Loss
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