Electron transfer and bond-forming reactions following collisions of Cl2+ and HCl2+ with CO

Abstract

Collisions between Cl(2+) and CO have been investigated using time-of-flight mass spectrometry over a collision energy range between 2.2 eV and 7.1 eV in the centre-of-mass frame. The formation of Cl(+), CO(+) and C(+) in electron transfer reactions has been detected and an unusual bond-forming reaction which generates CCl(2+) has also been observed. The reactive cross-sections, in arbitrary units, for the electron transfer reactions have been evaluated. To extract these cross sections we employ a new method of analysing mass spectral intensities for crossed-beam experiments, an algorithm which allows inter-comparison of the fluxes of all the ionic products from the electron transfer reactions. The observed electron transfer reactivity has been rationalized by calculations based on Landau-Zener theory. To account for the observation of CCl(2+), we have calculated the relevant energetics showing that the lowest lying doublet state of this dication is bound and is energetically accessible at our collision energies. These energetic arguments indicate that electron transfer in the exit channel between the separating CCl(2+) and O atom probably forms C(+) ions via the dissociation of CCl(+). Additionally, collisions between HCl(2+) and CO have been studied at collision energies from 2.2 to 7.0 eV in the centre-of-mass frame. In this collision system, proton transfer to form HCO(+) is observed to compete efficiently with dissociative and non-dissociative electron transfer.

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

“…For example, for increased sensitivity, the analysis MS can be replaced by a time-of-flight (TOF) instrument to enhance sensitivity, but this improvement comes at the expense of some of the information on the angular scattering and energetics of the reaction products. [44][45][46][47] …”

Electron transfer and bond-forming reactions following collisions of I2+with CO and CS2

“…[7][8][9][10][11][12][13][14][15][16][17][18] Specifically, the "reaction-window" concept, arising from an application of Landau-Zener theory to dication-neutral collisions, readily explains the SET reactivity in these encounters at low collision energies. [9][10][11]13,14,[18][19][20][21][22] Scattering experiments, employing crossed-beam mass spectrometers, guided ion beams and coincidence techniques, have also been used to elucidate the detailed mechanisms of dicationic SET reactivity, usually revealing a direct pathway. [9,11,14,[21][22][23][24][25][26][27][28] More recently, similar experiments have been performed to help understand the dynamics of double electron transfer (DET) reactions in dication-neutral collisions.…”

“…Past experiments have focused predominantly on the bond-forming chemistry of the Ar 2+ dication following collisions with various neutrals. [9,19,[45][46][47][48] For example, collisions between Ar 2+ with CO, CO2, O2 and N2 form ArC 2+ , ArO + , ArO 2+ and ArN 2+ respectively, albeit with low yield.…”

Bond Formation with Maintenance of Twofold Charge: Generation of C2O32+ in the Reaction of CO22+ with CO2

“…[20,21] The energy behavior of these competing reactions clearly demonstrates that the formation of C 2 O 3 2+ occurs as a quasi-thermal process, as the signal intensity of the dicationic coupling product has a sharp maximum at low collision energies, whereas the yields of the monocations formed by ET are almost energy-independent ( Figure 2). [22] For C 2 O 3 2+ , Pyykkö and Runeberg [11] suggested the cumulene structure OCOCO 2+ with a singlet ground state formally arising from double ionization (and cleavage) of the CÀC bond in oxirandione. To gain further insight into the isomers involved and to rationalize the observed isotope patterns in the reactions of labeled reagents, we performed exploratory computational studies.…”