Interaction between the ion dipole and the ion-induced dipole in reactions of the polar ion ArH+3

Abstract

The reactions of the highly polar ion ArH+3 with the nonpolar neutrals Xe, Kr, CH4, CO, NO, O2, and N2 and with the polar neutrals SO2, H2O, NH3, CH3I, and C2H5I have been investigated in a selected ion flow drift tube experiment at near thermal conditions. The rate coefficients obtained have typically 15%–35% larger values than the collisional limiting values kL and kADO obtained by the Langevin and ADO (average dipole orientation) theory, respectively. These data are explained on the basis of the interaction between the dipole of ArH+3 and the ion-induced dipole and the permanent dipole, respectively, of the neutral reactants. Rate coefficients for the reactions of H+3 with the above neutrals were also obtained for comparison, as well as the zero field mobility of ArH+3 in helium being (18.5±1.5) cm2/V s. The ion KrD+3 (KrH+3) was detected unambiguously for the first time. Its dissociation energy is larger than 0.29 eV which is the lower limit of the dissociation energy of ArH+3.