Bond‐Forming Reactions of Small Triply Charged Cations with Neutral Molecules

Abstract

Time‐of‐flight mass spectrometry reveals that atomic and small molecular triply charged cations exhibit extensive bond‐forming chemistry, following gas‐phase collisions with neutral molecules. These experiments show that at collision energies of a few eV, I3+ reacts with a variety of small molecules to generate molecular monocations and molecular dications containing iodine. Xe3+ and CS23+ react in a similar manner to I3+, undergoing bond‐forming reactions with neutrals. A simple model, involving relative product energetics and electrostatic interaction potentials, is used to account for the observed reactivity.

Dynamics of chemical reactions of multiply-charged cations: Information from beam scattering experiments

“…The model was successfully applied in many cases including reactions of multiply-charged fullerenes with molecules [38] and, quite recently, to reactions of triply-charged ions with neutral molecules [39]. Also, it is in agreement with the occurrence of bond-forming reactions of aryl dications with small and larger [ ( F i g .…”

Bond-Forming Chemistry in the Gas-Phase Reactions of Atomic and Molecular Dications and Trications

“…In reactions with larger neutrals, such specificity does not arise as product channels involving both iodine-containing monocations and dications are equally exothermic. Bond-forming reactions of molecular trications are also observed, 103 and the detailed dynamics of such reactions are currently under investigation using coincidence techniques. 113 …”

“…[109][110][111][112] Investigations of the low-energy reactivity of I 3+ , Xe 3+ , and CS 2 3+ surprisingly revealed a rich bond-forming reactivity, albeit in competition with single-and double-electron transfer. 103 Bond-forming reactions of iodine trications with diatomic molecules are found to favor the formation of a molecular dication incorporating the iodine atom together with an atomic monocation: I 3 + + CO ! IO 2 + + C + !…”

“…103 Ready rationalization of the unusual form of this bond-forming reactivity, and its competition with electron transfer, was allowed by the development of the model of dication bond-forming reactivity presented earlier ( Figure 10). Briefly summarizing this development, 103 in collisions of I 3+ with a diatomic neutral, we find that the relative energetics of the bond-forming product asymptotes commonly ensure that the most exothermic bond-forming channels involve the formation of a molecular dication containing the I atom, together with an atomic monocation (e.g., IO 2+ + C + ), rather than an iodine-containing molecular monocation together with an atomic dication (e.g., IO + + C 2+ ). Thus, in collisions with CO, the first curve crossing the separating products encounter in the exit channel efficiently diverts the exit channel flux to form IO 2+ or IC 2+ .…”

“…103 Long-lived small molecular trications have been known experimentally for many years and, of course, possess significant energies due to internal Coulomb repulsion. [104][105][106][107][108] It should be noted that the reactivity of these small, highly charged species is dramatically different from that of larger, multiply charged ions formed, for example, from biomolecules where the multiple charges can be dispersed and well separated; the reactivity of these large multiply charged ions has been the subject of a number of recent mass spectrometric investigations.…”