Scattering of electrons from 1-butene, H₂C=CHCH₂CH₃, and 2-methylpropene, H₂C=C(CH₃)₂, molecules

Abstract

We report absolute grand total cross sections (TCSs) for electron scattering from 1-butene (H 2 C=CHCH 2 CH 3 ) and 2-methylpropene (H 2 C=C(CH 3 ) 2 ) molecules, measured at electron impact energies ranging from 1 to 400 eV and from 1 to 350 eV, respectively, using a linear electron-transmission technique. The general shape of cross sections for both butene isomers looks similar. Two structures in each TCS energy curve are discernible: a small peak in the vicinity of 2.3 eV and a pronounced very broad enhancement with the maximum located around 8 eV. The magnitude of TCS for 2-methylpropene appears somewhat higher than that for 1-butene below 20 eV, while above 70 eV the TCS curves practically overlap. In addition, comparison is made of TCSs for an ethylene (H 2 C=CH 2 ) molecule and its mono and double methyl-substituted derivatives: propene (H 2 C=CHCH 3 ) and 2-methylpropene.

Electron-scattering cross sections for 1-pentene, H2C=CH–(CH2)2CH3, molecules

“…Figure 3 shows that similar, however more distinct structures in the TCS curves located within 1.5 and 2.5 eV have also been observed for the ethylene molecule (H 2 C=CH 2 ) and its straight-chain derivatives: propene (H 2 C=CH-CH 3 ) and 1-butene (H 2 C=CH-CH 2 CH 3 ). The origin of these structures for molecules of the ethylenic series has been attributed (for references see Możejko et al 2012b) to the attachment of the impinging electron into the lowest unoccupied π * molecular orbital associated with the C=C bond, resulting in the formation of the π * temporary negative ion state (the π * shape resonance).…”

Electron collisions with methyl-substituted ethylenes: Cross section measurements and calculations for 2-methyl–2-butene and 2,3-dimethyl–2-butene

“…To keep conformity, all displayed TCS results are taken from experiments performed in our laboratory. 28,[33][34][35] It is evident from Fig. 3 that the compared TCS curves show a very similar behavior over the whole investigated energy range.…”

Recent total cross section measurements in electron scattering from molecules

“…Molecular targets, and references in the text Baylor University, C2H4 (ethylene), C3H6 (propene), C4H8 (butene), C4H6 (1,3-butadiene) [144]; Waco, USA C2H2 (acetylene), C3H4 (propyne) [145] Gdańsk University HCOOH (formic acid) [86]; C4H4O (furan) [87]; C3H3NO (isoxazole) [90]; of Technology, C5H5N (pyridine) [107]; C5H10O (tetrahydropyran) [111]; Gdańsk, Poland (CH3)2CO (acetaldehyde) [116]; (CF3)2CO (hexafluoroacetone) [117]; X(CH3)4 (X=C,Si,Ge) [126]; SnCl4 [127]; C4H8 (1-butene, 2-methylpropene) [136]; C5H10 (1-pentene) [138]; C5H10 (2-methyl-2-butene), C6H12 (2,3-dimethyl-2-butene) [137]; C2H2 (acetylene), C4H6 (1-butyne) [139]; C4H6 (1,2-butadiene) [141]; C5H6 (2-methyl-1-buten-3-yne) [142]; C5H8 (2-methyl-1,3-butadiene) [143] Institute of Technology, N2 (nitrogen) [62]; O2 (oxygen) [71] Tokyo, Japan Instituto de Matemáticas N2 (nitrogen) [63]; CH2Cl2 (dichloromethane) [124] y Fisica Fundamental, C4H4S (thiophene) [88]; C5H4O2 (furfural) [89]; C4H8O (tetrahydrofuran) [94]; (CSIC), Madrid, Spain C6H6 (benzene) [98]; C6H5OH (phenol) [103]; C5H5N (pyridine) [105,106]; C4H4N2 (pyrimidine) [109]; C4H4N2 (pyrazine) [110]; C6H4O2 (para-benzoquinone) [112]; C4H3F7O (sevoflurane) […”

“…At higher collisional energies, where resonant processes are not so important, the TCS magnitude for compared molecules increases with the size of the central atom in target molecule. TCS results are taken from experiments performed with the same experimental setup [134][135][136][137]. In general, the compared TCS curves show very similar behavior over the whole investigated energy range.…”

“…In Figure 22 TCS energy curves for 1-butene [H 2 C=CHCH 2 CH 3 ] (from Ref. [136]) and 1-pentene [H 2 C=CH-(CH 2 ) 2 CH 3 ] (from Ref. [138]) measured with the same apparatus are also included.…”