I. Szamrej

Bio: I. Szamrej is an academic researcher. The author has contributed to research in topics: Electron capture & Ion. The author has an hindex of 4, co-authored 4 publications receiving 22 citations.

Thermal electron capture by some halopropanes

Abstract: Thermal electron attachment rate constants for CF 3 CHClCH 3 , CF 2 ClCFClCF 3 and CBrF 2 CH 2 CH 2 Br have been measured with electron swarm method. Corresponding rate constants are equal to 7.6×10 −11 , 5.5×10 −9 and 1.5×10 −8 cm 3 molecule −1 s −1 , respectively. The dissociative electron attachment (DEA) spectra for nine haloalkanes have been determined using negative ion mass spectrometry. The correlation between rate constants, position of the DEA peaks and vertical attachment energy (VAE) available in literature has been demonstrated.

On the kinetics of thermal electron attachment to perfluoroethers

Abstract: In this Letter we report the results of the measurements of the rate coefficients for thermal attachment to several perfluoroethers namely perfluorodiglyme (C 6 F 14 O 3 ), perfluorotriglyme (C 8 F 18 O 4 ), perfluoropolyether (CF 3 –(OCF(CF 3 )CF 2 ) n –(OCF 2 ) m –OCF 3 ) and perfluorocrownether ((C 2 F 4 O) 5 ). Rate coefficients were obtained under thermal conditions in the temperature range 298–378 K. The increase of the rates with temperature follows the Arrhenius law and the activation energies have been obtained from the slope of the ln( k ) vs. 1/ T . The respective values of the rate coefficients (at 298 K) and activation energies are as follows: 7.7 ± 1.2 × 10 −11 cm 3 s −1 (0.18 ± 0.005 eV), 6.7 ± 2.1 × 10 −11 cm 3 s −1 (0.25 ± 0.004 eV), 2.1 ± 0.2 × 10 −10 cm 3 s −1 (0.16 ± 0.010 eV), 3.1 × 10 −11 cm 3 s −1 (0.27 ± 0.003 eV) for C 6 F 14 O 3 , C 8 F 18 O 4 , CF 3 –(OCF(CF 3 )CF 2 ) n –(OCF 2 ) m –OCF 3 and (C 2 F 4 O) 5 .

Thermal electron capture by some chlorobromopropanes

Abstract: Thermal electron attachment rate constants for CH2ClCHBrCH3 and CH2ClCH2CH2Br have been measured using electron swarm method. Corresponding rate constants are equal to 3.5×10-10 and 2.5×10-10 cm3 molec-1 s-1, respectively. Parallely, negative ion mass spectra of these compounds as well as CH2FCH2Br, CH2ClCH2Br, CH2BrCH2Br and CF3CHClBr has been measured with negative ion mass spectrometry method. The rate constants have been compared with the negative ion mass spectra.

Kinetics of low energy electron attachment to some fluorinated alcohols in the gas phase

Abstract: Thermal electron attachment processes in the mixtures of CH 3 CH 2 OH, CF 3 CH 2 OH, CF 3 CF 2 CH 2 OH, (CF 3 ) 2 CHOH and CH 3 CH(OH)CF 3 with carbon dioxide have been investigated using an electron Pulsed Townsend technique. Measurements were carried out in the temperature range (298–413) K. The obtained rate coefficients depended on temperature in accordance to Arrhenius equation. From the fit to the experimental data points with function ln( k ) = ln( A )− E a / k B T the activation energies ( E a ’s) were determined. The rate coefficients at 298 K are equal to 3.2 × 10 −13 cm 3 s −1 , 5.1 × 10 −11 cm 3 s −1 , 1.1 × 10 −10 cm 3 s −1 , 3.0 × 10 −10 cm 3 s −1 and 2.6 × 10 −11 cm 3 s −1 and activation energies are: 0.37 eV, 0.25 eV, 0.28 eV, 0.20 eV and 0.23 eV, respectively for CH 3 CH 2 OH, CF 3 CH 2 OH, CF 3 CF 2 CH 2 OH, (CF 3 ) 2 CHOH and CH 3 CH(OH)CF 3 .

Rate constants of electron attachment to chlorobenzenes measured by atmospheric pressure nitrogen corona discharge electron attachment ion mobility spectrometry

Abstract: Using atmospheric pressure nitrogen corona discharge electron attachment ion mobility spectrometry (APNCD-EA-IMS), the rate constants of electron attachment to 1,2-dichlorobenzene, 1,3-dichlorobenzene, 1,4-dichlorobenzene, 1,2,4-trichlorobenzene and α,α,α-trichlorotoluene have been determined at ambient temperature as a function of the average electron energy in the range from 0.35 to 0.65 eV based on the experimental measurements of the negative ion mobility spectra. The rate constants are in the order of magnitude of ∼10 −9 cm 3 molecule −1 s −1 . The ability of the dichlorobenzene isomers to capture the electrons has been found to decrease following the order of 1,2-chlorobenzene, 1,3-chlorobenzene and 1,4-chlorobenzene, which is different from previously reported results in the literature. For electron attachment to 1,2,4-trichlorobenzene and α,α,α-trichlorotoluene, the experimental measurements show that α,α,α-trichlorotoluene has a higher rate constant than 1,2,4-trichlorobenzene.

The influence of the temperature on electron attachment to some halocontaining molecules

Abstract: Thermal electron attachment rate coefficients for CH 2 ClCHClCH 2 Cl, CH 2 ClCH 2 Br, CH 2 ClCH 2 CH 2 Br and CF 2 ClCFCl 2 have been measured using the Pulsed Townsend technique over the temperature range T = 298–358 K. The corresponding rate coefficients at 298 K are equal to 1.7(4) × 10 −10 , 7.9(15) × 10 −10 , 3.4(5) × 10 −10 and 3.1(1) × 10 −8 cm 3 molec. −1 s −1 , respectively. With rising temperature we have observed an increase of the rate coefficients k ( T ), which shows an Arrhenius-type behaviour. Activation energies E a of 0.16(1) eV (CH 2 ClCHClCH 2 Cl), 0.12(1) eV (CH 2 ClCH 2 Br), 0.20(1) eV (CH 2 ClCH 2 CH 2 Br) and 0.08(1) eV (CF 2 ClCFCl 2 ) were determined from the fit to the experimental data points with a function ln( k ) = ln( A ) − E a / k B T .

Empty level structure and dissociative electron attachment cross sections in bromo and chloro dihaloalkanes.

Abstract: The energies of electron attachment associated with temporary occupation of the C−Br and/or C−Cl virtual σ* orbitals of dichloro, bromochloro, and dibromo alkanes are measured in the gas phase with electron transmission spectroscopy (ETS). The corresponding orbital energies of the neutral molecules, supplied by HF/6-31G(d)//MP2/6-31G(d) calculations and scaled using an empirically calibrated linear equation, are compared with the experimental vertical attachment energies (VAEs). The largest energy splittings between the first two σ* anion states are found in the methane derivatives, but two distinct resonances are also observed in the bromochloro and dibromo ethane derivatives. The temporary anions observed in ETS may dissociate, producing Br− and Cl− negative fragments with widely varying cross sections over the dihaloalkanes studied. The absolute total dissociative electron attachment (DEA) cross sections are evaluated, and their peak values are compared with the corresponding VAEs. In the mixed bromoch...

Thermal electron capture by some halopropanes

Abstract: Thermal electron attachment rate constants for CF 3 CHClCH 3 , CF 2 ClCFClCF 3 and CBrF 2 CH 2 CH 2 Br have been measured with electron swarm method. Corresponding rate constants are equal to 7.6×10 −11 , 5.5×10 −9 and 1.5×10 −8 cm 3 molecule −1 s −1 , respectively. The dissociative electron attachment (DEA) spectra for nine haloalkanes have been determined using negative ion mass spectrometry. The correlation between rate constants, position of the DEA peaks and vertical attachment energy (VAE) available in literature has been demonstrated.

Electron attachment rate constant measurement by photoemission electron attachment ion mobility spectrometry(PE-EA-IMS

Abstract: Photoemission electron attachment ion mobility spectrometry (PE-EA-IMS), with a source of photoelectrons induced by vacuum ultraviolet radiation on a metal surface, has been developed to study electron attachment reaction at atmospheric pressure using nitrogen as the buffer gas. Based on the negative ion mobility spectra, the rate constants for electron attachment to tetrachloromethane and chloroform were measured at ambient temperature as a function of the average electron energy in the range from 0.29 to 0.96 eV. The experimental results are in good agreement with the data reported in the literature.