Intermediate energy electron impact excitation of composite vibrational modes in phenol

Abstract

Absolute cross sections for vibrational excitations of cytosine by low energy electron impact J. Chem. Phys. 137, 115103 (2012) We report differential cross section results from an experimental investigation into the electron impact excitation of a number of the low-lying composite (unresolved) vibrational modes in phenol (C 6 H 5 OH). The measurements were carried out at incident electron energies in the range 15-40 eV and for scattered-electron angles in the range 10-90• . The energy resolution of those measurements was typically ∼80 meV. Calculations, using the GAMESS code, were also undertaken with a B3LYP/aug-cc-pVDZ level model chemistry, in order to enable us to assign vibrational modes to the features observed in our energy loss spectra. To the best of our knowledge, the present cross sections are the first to be reported for vibrational excitation of the C 6 H 5 OH molecule by electron impact. C 2015 AIP Publishing LLC. [http://dx

Integral cross sections for electron impact excitation of vibrational and electronic states in phenol

“…3 We were therefore interested to see how those physico-chemical properties manifested themselves, if at all, in the behaviour of the measured composite vibrational-mode and/or electronic-state excitation ICSs. In addition, Neves et al 21 found some evidence for a higher-lying shape resonance enhancing the phenol cross sections vis à vis those of benzene. Support for the existence of that resonance was also found in our Schwinger Multichannel Method with Pseudo-potentials (SMCPP) calculations for the elastic channel 20 and our experimental total cross section measurements.…”

“…To this end, we have conducted a series of joint experimental and theoretical studies looking at the behaviour of electron-phenol scattering processes. Specifically, results for phenol's (e, 2e) triple differential cross sections (DCSs), 19 elastic scattering and total cross sections (TCS), 20 vibrational excitation differential cross sections, 21 and excited electronic-state differential cross sections 22 have all thus far been reported. In addition, a) Author to whom correspondence should be addressed.…”

“…21,23 Nonetheless, when simulating atmospheric plasma behaviour, etc., it is actually the integral cross sections (ICSs) (and the momentum transfer cross section) that are of most relevance to the modelling communities. [11][12][13][14][15][16][17][18] As a consequence, in this short paper, we report on our derivation of vibrational-mode and electronicstate ICSs from our previously published differential cross section measurements.…”

“…In Sec. II, we briefly describe our procedure for deriving ICSs from our DCS measurements, 21,22 as well as our independent atom model with screened additivity rule (IAM-SCAR) computations. References to relevant papers describing how our f -scaled Born-level and energy-corrected and f -scaled Born-level (BE f -scaled) dipole-allowed ICS were determined are also given in this section.…”

“…[11][12][13][14][15][16][17][18] As a consequence, in this short paper, we report on our derivation of vibrational-mode and electronicstate ICSs from our previously published differential cross section measurements. 21,22 Phenol also possesses a range of physico-chemical properties which, from our experience with other collision systems, [24][25][26][27][28][29][30] are anticipated to play important roles in its scattering dynamics. Specifically, phenol has a permanent dipole moment of magnitude ∼1.42 D 3 and a significant average dipole polarisability of 10.53 Å 3 .…”