State selected ionndash;molecule reactions by a coincidence technique. XV. Hydrogen atom abstraction as an electron jump followed by proton transfer in the ND+3(v)+NH3and NH+3(v)+ND3reactions

摘要

The effects of the vibrational excitation of the ngr;2mode of ND+3(v) and NH+3(v) on the three channels of their reaction with NH3and ND3, respectively, are investigated up tov=12 in the centerhyphen;ofhyphen;mass kinetic energy range from 0.9 to 4.5 eV by use of the TESICO technique. The ratio (ggr;) of the hydrogen/deuterium atom abstraction cross section over the competing deuteron/proton transfer cross section has a maximum systematically at a vibrational level (vmax) slightly higher than that giving maximum Franckndash;Condon factor (vFC) for the neutralization of ND+3(v)/NH+3(v). A new reaction model based on a nonadiabatic transition theory and the potential energy surface calculated for the ammonia dimer cation is proposed to explain the experimental results. The hydrogen/deuterium atom abstraction reaction is interpreted as a near resonant electron jump at larger intermolecular separation followed by proton/deuteron transfer which proceeds on the lsquo;lsquo;electron (charge)ndash;transferredrsquo;rsquo; potential surface.