Electron scattering on C3H6 isomers

Abstract

Absolute total cross sections (TCSs) for the electron scattering from two structured isomers of C 3 H 6 (propene and cyclopropane) have been determined over the energy range from 0.5 up to 370 eV in a linear electron-beam transmission experiment. The TCS for propene is generally higher than that for cyclopropane, especially around the main maximum which in both TCSs is centred near 9.5 eV. Besides this broad enhancement, already observed in earlier measurements, some additional new TCS features-specific for each targethave been noticed in the present experiment. The TCS for propene has a distinct resonant narrow peak visible at around 2.2 eV. For cyclopropane, a very weak hump at around 2.6 eV and a shoulder near 6 eV on the low-energy slope of the cross section function are distinguishable. On the descending side of the cross section energy dependence the change of the slope is located at around 40 eV. These weak cyclopropane features seem to be common for cyclic molecules. The present results are compared with earlier C 3 H 6 TCS measurements available above 4 eV and with calculations above 10 eV. A distinct difference in magnitudes is visible, especially around the main maximum. On the basis of the present propene and previous hexafluoropropene data a fluorination effect is indicated and discussed.

Electron-impact vibrational excitation of cyclopropane

“…We find satisfactory agreement both for the integral elastic cross section plotted as a function of electron energy shown in 39 and squares, 40 while circles represent the previously reported total cross section. 41 Present experimental data are denoted by diamonds. Present calculations are shown as red line, while the orange line represents previous SMC, 40 and blue line represents results of single-center expansion method.…”

Electron scattering from alkenes in the energy range 200–4500 eV

“…In recent years, there is increased interest in the study of total electron scattering cross sections (TCS) of hydrocarbons, both experimentally and theoretically, because of the increases demand in many areas of pure and applied sciences [1][2][3][4][5][6][7][8]. It is convenient in these applications if there is an analytical expression to determine the TCS of a given hydrocarbon at a given energy.…”

“…Also, they have stressed the isomer effects and dependence of the geometrical dimensions of the molecule in those TCS. Szmytkowski and Kwitnewski [2][3][4] have reported the TCS of several hydrocarbons at energies 0.5-370 eV and discussed the isomer effect in TCS at these energies. Recently, Sueoka et al [5,6] measured the TCS of a series of alkanes and cyclo-alkanes at energies 0.4-1000 eV and discussed the systematic trends in TCS.…”

“…Three experimental groups: Floeder et al [9], Nishimira and Tawara [10], and Sueoka and Mori [13], have reported the TCS of C 2 H 4 at energies 400 eV and lower. Szmytkowski and Kwitnewski [2][3][4] have reported the TCS of one alkene, C 3 H 6 (propene), and another C-C double bonded hydrocarbon, C 4 H 6 (1,3-butadiene) between the energies 0.5-370 eV.…”

Experimental and theoretical cross sections for positron scattering from the pentane isomers

“…Electronic mail: luca.chiari@rs.tus.ac.jp. (Kossoski et al, 2011), the hydrocarbons C 3 H 4 (Nakano et al, 2002;Szmytkowski and Kwitnewski, 2002b;Lopes and Bettega, 2003;Makochekanwa et al, 2003;Sanchez et al, 2005;, C 3 H 6 (Mott and Massey, 1965;Floeder et al, 1985;Nishimura and Tawara, 1991;Winstead et al, 1992;Szmytkowski and Kwitnewski, 2002a;Makochekanwa et al, 2005;2008;and Tan et al, 2007), C 4 H 6 Kwitnewski, 2003a andLopes et al, 2004a), C 4 H 8 (Lopes et al, 2004b andBettega et al, 2006), and C 4 H 10 (Floeder et al, 1985;Lopes et al, 2004b;and Bettega et al, 2007), as well as five-membered heterocyclic, aromatic compounds (Kossoski and Bettega, 2013). On the other hand, very little is known about the interaction of positrons with isomers, with just a few investigations for hydrocarbons (Floeder et al, 1985;Kimura et al, 2000;Makochekanwa et al, 2003;2008;Sueoka et al, 2005;and Nunes et al, 2015) and chiral enantiomers being available.…”