The generalized mobility curve for alkali ions in rare gases: Clustering reactions and mobility curves

Abstract

The measurements of mobility values for alkali ions in rare gases at room temperature over a wide range of E/N were completed for all 25 combinations. The experimental mobility curves were compared with a generalized mobility curve calculated from a model potential consisting of an inverse 8th power repulsive term and 6th and 4th power attractive terms, which took into account the core size, and potential well depths being determined for all the ion–gas combinations except for the cases of Rb+–He and Cs+–He from the relation between the observed maximum mobility and the ion energy. Experimental generalized mobility curves for alkali ions in rare gases were obtained using these well depths. It was found that all the experimental mobility curves were unified into a single curve using the model potential including the core size. The rate coefficients were measured for backward clustering reaction: Li+Ar–Ar, Li+Kr–Kr, and Li+Xe–Xe, using a drift tube. It was found that the activation energy is roughly half the well depth, comparing the well depths 0.550 eV for Li+–Ar, 0.710 eV for Li+–Kr, and 0.901 eV for Li+–Xe, with the activation energies obtained by Arrhenius plot for the backward reactions 0.34 eV for Li+Ar, 0.45 eV for Li+Kr, and 0.49 eV for Li+Xe.

Cationic Noncovalent Interactions: Energetics and Periodic Trends

“…Table lists BDEs for interaction between various metal cations and the rare gases (Rg). Most of these data were acquired using mobility − ,− or scattering ,− techniques. Among these data, Takebe has reported well depths for most of the alkali cation–rare gas interactions, but in many cases, these values are considerably higher than those obtained from alternate sources.…”

“…Most of these data were acquired using mobility − ,− or scattering ,− techniques. Among these data, Takebe has reported well depths for most of the alkali cation–rare gas interactions, but in many cases, these values are considerably higher than those obtained from alternate sources. Reasons for these differences have been commented on by Viehland .…”

“…Multiple references refer to the average from all listed references. E = single temperature equilibrium, H = high-pressure temperature-dependent equilibrium, M = mobility, − ,− P = photodissociation and ionization, , S = scattering, ,, and T = threshold of endothermic reaction. − b Average of values from multiple experiments listed in ref . c Corresponds to an excited electronic state of Ni + . d Relative free energy ( E ) anchored to D (Fe + –CH 4 ) from ref and adjusted to 0 K in ref . …”

“…Multiple references refer to the average from all listed references. E = single temperature equilibrium, H = high-pressure temperature-dependent equilibrium, M = mobility, − ,− P = photodissociation and ionization, , S = scattering, ,, and T = threshold of endothermic reaction. − …”

Effect of adsorbate mass on an Eley–Rideal reaction. Reactive scattering of Cs+ from noble gases and N2 adsorbed on Ru(0001) surfaces at hyperthermal energy

“…13 In addition to the mass of the adsorbate, its binding energies to the surface and to Cs + can also affect the magnitude of the RIS cross-section. According to gas-phase mobility studies and theoretical estimations, 23,24 the binding energies between Cs + and noble gases are 0.08 eV (Ar), 0.11 eV (Kr) and 0.10 eV (Xe). The adsorption energies of these gases to the surface are 0.15 eV (Xe), 0.1 eV (Kr) and 0.07 eV (Ar).…”