We study dissociative electron attachment to furan (FN) (C(4)H(4)O), tetrahydrofuran (THF) (C(4)H(8)O), and fructose (FRU) (C(6)H(12)O(6)) using crossed electron/molecular beams experiments with mass spectrometric detection of the anions. We find that FN and THF are weak electron scavengers and subjected to dissociative electron attachment essentially in the energy range above 5.5 eV via core excited resonances. In striking contrast to that, FRU is very sensitive towards low energy electrons generating a variety of fragment ions via a pronounced low energy feature close to 0 eV. These reactions are associated with the degradation of the ring structure and demonstrate that THF cannot be used as surrogate to model deoxyribose in DNA with respect to the attack of electrons at subexcitation energies (<3 eV). The results support the picture that in DNA the sugar moiety itself is an active part in the initial molecular processes leading to single strand breaks.

Differential cross sections ͑DCSs͒ for elastic scattering of electrons from pyrimidine ͑C 4 H 4 N 2 ͒ are presented for incident energies from 50 to 300 eV. The measurements were performed using a cross beam technique, for scattering angles from 20°to 110°. The relative DCSs were measured as a function of both the angle and incident energy and the absolute DCSs were determined using the relative flow method. The calculations of electron interaction cross sections are based on a corrected form of the independent-atom method, known as the screen corrected additivity rule procedure and using an improved quasifree absorption model. Calculated results agree very well with the experiment.

The electronic spectroscopy of isolated tetrahydrofuran (THF) in the gas phase has been investigated using high-resolution photoabsorption spectroscopy in the 5.8-10.6 eV with absolute cross section measurements derived. In addition, an electron energy loss spectrum was recorded at 100 eV and 10° over the 5-11.4 eV range. The He(I) photoelectron spectrum was also collected to quantify ionisation energies in the 9-16.1 eV spectral region. These experiments are supported by the first high-level ab initio calculations performed on the excited states of the neutral molecule and on the ground state of the positive ion. The excellent agreement between the theoretical results and the measurements allows us to solve several discrepancies concerning the electronic state spectroscopy of THF. The present work reconsiders the question of the lowest energy conformers of the molecule and its population distribution at room temperature.

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The position of the critical minimum in elastic electron–krypton scattering at intermediate electron energies was investigated. Differential cross sections (DCSs) were measured as a function of both incident electron energy (100–260 eV) and scattering angle (30–110°), in small steps around the critical minimum. The energy dependence of the angular positions of DCS minima were determined. Also, the positions of minima in energy-dependent DCSs were obtained at several fixed scattering angles close to the critical value. The position of the critical minimum was determined to be at 187.9 ± 0.5 eV and 83.0° ± 0.2°. However, the strong dependence of critical energy on small changes of critical angle was found. The obtained results are compared with the most recent theoretical calculations.