Positron and electron scattering from tetrahydrofuran

Cross section data for electron scattering from DNA are important for modelling radiation damage in biological systems. Triply differential cross sections for the electron impact ionization of the highest occupied outer valence orbital of tetrahydrofurfuryl alcohol, which can be considered as an analogue to the deoxyribose backbone molecule in DNA, have been measured using the (e,2e) technique. The measurements have been performed with coplanar asymmetric kinematics at an incident electron energy of 250 eV, an ejected electron energy of 20 eV, and at scattered electron angles of −5 • , −10 • , and −15 • . Experimental results are compared with corresponding theoretical calculations performed using the molecular 3-body distorted wave model. Some important differences are observed between the experiment and calculations.

Section: Introductionmentioning

confidence: 99%

Dynamical (e,2e) studies of tetrahydrofurfuryl alcohol

Bellm

Builth-Williams

Jones

et al. 2012

“…Condensedphase experiments on thymidine and a single-strand oligonucleotide have demonstrated that slow electrons do indeed break the C-O phosphate-sugar bonds as well as the C-N base-sugar bonds, [60][61][62] and C-O bond breaking was also found in gas-phase DA to a model phosphodiester. 63 A few electron-collision studies, experimental and theoretical, have looked at the individual backbone constituents, i.e., ribose or deoxyribose and a phosphate group, [64][65][66][67][68][69] and others have also been made of electron collisions with backbone analogs such as tetrahydrofuran, 29,65,[68][69][70][71][72][73][74][75][76][77][78][79] tetrahydrofurfuryl alcohol, 71,72,80,81 fructose, 79 and dibutyl phosphate. 63 However, the only electron collision measurements involving nucleosides that we are aware of are the study by Zheng et al of thymine desorption from condensed-phase deoxythymidine 60 mentioned earlier, and the gas-phase studies by Abdoul-Carime et al 82 and by Denifl et al 83 of DA to deoxythymidine and 5-bromouridine, respectively.…”

Section: Introductionmentioning

confidence: 99%

Interaction of low-energy electrons with the purine bases, nucleosides, and nucleotides of DNA

Winstead¹,

McKoy²

2006

The authors report results from computational studies of the interaction of low-energy electrons with the purine bases of DNA, adenine and guanine, as well as with the associated nucleosides, deoxyadenosine and deoxyguanosine, and the nucleotide deoxyadenosine monophosphate. Their calculations focus on the characterization of the * shape resonances associated with the bases and also provide general information on the scattering of slow electrons by these targets. Results are obtained for adenine and guanine both with and without inclusion of polarization effects, and the resonance energy shifts observed due to polarization are used to predict * resonance energies in associated nucleosides and nucleotides, for which static-exchange calculations were carried out. They observe slight shifts between the resonance energies in the isolated bases and those in the nucleosides.

“…5. TCSs (×10 −20 m 2 ) for positron scattering from the cyclic ethers, as studied previously [8][9][10][11] at the University of Trento and also as a part of this investigation. See legend on the figure for further details.…”

Section: Tetrahydropyranmentioning

confidence: 91%

“…Some of the important physico-chemical properties of the present cyclic ethers and also those from our previous investigations. [8][9][10][11] Note that (a) denotes the value pertaining to the first or global energy minimum conformer, while (b) denotes the value pertaining to the second or next highest energy conformer. drawn from the rare gases, 27,28 for example.…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Positron scattering from the cyclic ethers oxirane, 1,4-dioxane, and tetrahydropyran

Zecca

Trainotti

Chiari

et al. 2012

In this paper we report original measurements of total cross sections (TCSs) for positron scattering from the cyclic ethers oxirane (C 2 H 4 O), 1,4-dioxane (C 4 H 8 O 2 ), and tetrahydropyran (C 5 H 10 O). The present experiments focus on the low energy range from ∼0.2 to 50 eV, with an energy resolution smaller than 300 meV. This study concludes our systematic investigation into TCSs for a class of organic compounds that can be thought of as sub-units or moieties to the nucleotides in living matter, and which as a consequence have become topical for scientists seeking to simulate particle tracks in matter. Note that as TCSs specify the mean free path between collisions in such simulations, they have enjoyed something of a recent renaissance in interest because of that application. For oxirane, we also report original Schwinger multichannel elastic integral cross section (ICS) calculations at the static and static plus polarisation levels, and with and without Born-closure that attempts to account for the permanent dipole moment of C 2 H 4 O. Those elastic ICSs are computed for the energy range 0.5-10 eV. To the best of our knowledge, there are no other experimental results or theoretical calculations against which we can compare the present positron TCSs. However, electron TCSs for oxirane (also known as ethylene oxide) and tetrahydropyran do currently exist in the literature and a comparison to them for each species will be presented.