Cross sections for electron collision with pyridine [C$_{5}$H$_{5}$N] molecule

TL;DR

This study measures and analyzes the total electron scattering cross sections for pyridine across a wide energy range, compares it with benzene, and calculates elastic and ionization cross sections for pyridine and its halogenated derivatives.

Contribution

It provides the first comprehensive measurement of pyridine's total cross section and compares it with benzene, also calculating elastic and ionization cross sections for derivatives.

Findings

TCS decreases with energy, with a peak near 8.5 eV.

Weak structures below 10 eV suggest resonant scattering.

Calculated ECS and ICS agree with TCS above 40 eV.

Abstract

The absolute grand-total cross section (TCS) for electron scattering from pyridine, C$_{5}$H$_{5}$N, molecules has been measured at impact energies from 0.6 to 300 eV in the linear electron-transmission experiment. The obtained TCS energy dependence appears to be typical for targets of high electric dipole moment; the cross section generally decreases with rising energy, except for the 3-20 eV range, where a broad enhancement peaked near 8.5 eV is clearly visible. Below 10 eV, some weak structures which can be attributed to resonant scattering processes are also discernible. The present TCS energy dependence is compared with TCS experimental data obtained recently for energies above 13 eV by Traore Dubuis et al. [26]. The TCS for pyridine has been confronted with TCS for benzene to search how the replacement of the CH group in the benzene ring with the nitrogen atom influences the electron scattering process. In addition, for pyridine and its halogenated derivatives: 2-chloropyridine [2-C$_{5}$H$_{4}$ClN] and 2-bromopyridine [2-C$_{5}$H$_{4}$BrN], integral elastic (ECS) and ionization (ICS) cross sections have been calculated at intermediate and high electron-impact energies within semiempirical approaches. For pyridine the sum of ECS and ICS is in reasonable agreement with the measured TCS above 40 eV.