Penning ionization of N2O molecules by He*(2S3,1) and Ne*(P2,3) metastable atoms: A crossed beam study

Abstract

The energetics of [Rg... N2O]* autoionizing collision complexes (where Rg=He or Ne) and their dynamical evolution have been studied in a crossed beam apparatus, respectively, by Penning ionization electron spectroscopy (PIES) and by mass spectrometry (MS) techniques in the thermal energy range. The PIES spectra, detected by an electron energy analyzer, were recorded for both complexes at four different collision energies. Such spectra allowed the determination of the energy shifts for Penning electron energy distributions, and the branching ratios for the population of different electronic states and for the vibrational population in the molecular nascent ions. For the [Ne...N2O]* collision complex it was found, by MS, that the autoionization leads to the formation of N2O+, NO+, O+, and NeN2O+ product ions whose total and partial cross sections were measured in the collision energy range between 0.03 and 0.2 eV. The results are analyzed exploiting current models for the Penning ionization process: the observed collision energy dependence in the PIES spectra as well as in the cross sections are correlated with the nature of the N2O molecule orbitals involved in the ionization and are discussed in term of the Rg-N2O interaction potentials, which are estimated by using a semiempirical method developed in our laboratory.

Dynamics of gas phase Ne* + NH3 and Ne* + ND3 Penning ionisation at low temperatures

“…27 Similarly, the fraction of electronically excited N 2 O + Penning ions decreases with increasing collision energy, as found in the Ne * + N 2 O reaction. 62 The authors of the above studies did not propose any viable mechanisms that would explain the trends exhibited by the branching ratio as a function of the collision energy. More work from the Perugia laboratory on the Ne * + CH 3 X (X = Cl, Br) reaction has shown that the fraction of CH + 3 and CH 2 X + products grows with increasing collision energy, whereas the amount of CH 2 X + parent ions declines at higher E coll values.…”

Determination of structural parameters from advanced molecular electronic spectroscopy: The double ionization of nitrous oxide by synchrotron radiation

“…It is well known that N 2 O exhibits two one-electron absorptions in the lower energy region at 12.89 and 16.38 eV (Biondini et al 2005a;2005b), assigned as the first ionization of the two inequivalent nitrogen atoms in the N 2 O molecule, or rather to the two highest occupied molecular orbitals of the linear N-N-O moiety. In the higher energy range investigated here, ∼ 28-40 eV, a vertical transition occurs at ca.…”

Angular Distributions of Fragment Ions Produced by Coulomb Explosion of Simple Molecular Dications of Astrochemical Interest

“…The presence of N 2 O in the ISM has been demonstrated by microwave spectroscopy, whereas C 2 H 2 was detected by IR spectroscopic measurements [29]. On the other hand, the importance of nitrous oxide is well known in the Earth's atmosphere, where it is an important greenhouse gas and participates in ozone depletion [30,31]. Moreover, acetylene has been detected as a minor component in Titan's atmosphere (about 10 ppb) [32].…”