Is collision-induced dissociation of low-energy carbonyl sulfide cations adversely affected by asymmetry?

Eur. J. Mass Spectrom. 10, 221–224 (2004)
DOI: 10.1255/ejms.635

Is collision-induced dissociation of low-energy carbonyl sulfide cations adversely affected by asymmetry?

Anil K. Shukla
Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, USA

ABSTRACT:

We have measured relative abundances of fragment ions resulting from collision-induced dissociation of OCS⁺ ions in collision with xenon neutrals as a function of ion kinetic energy and scattering angle. The lowest energy dissociation product, S⁺, dominates at all energies up to 53 eV kinetic energy studied here. Surprisingly, the second most abundant dissociation channel is CS⁺ and not CO⁺ even though the thermochemical threshold for CO⁺ is lower than that for CS⁺ and CO⁺ is more abundant than CS⁺ in the normal mass spectrum of OCS. We do not observe any significant abundance of CO⁺ in this energy range, suggesting that collision-induced excitation and dissociation of OCS⁺ is significantly different to that of symmetric triatomic ions. A possible role of asymmetry in the molecular ion’s collisional activation via neutral collision is suggested for the different behavior.

Keywords: crossed-beam experiments, angular scattering, collision induced dissociation, carbonyl sulfide cation

You can buy this paper on-line in PDF format; it costs only £11.75. Just click on the BUY on-line button. You can pay on-line through a secure server and get access immediately.