THE INFLUENCE OF NEUTRAL REAGENTS ON THE EFFECTIVE RECOMBINATION ENERGY OF THE ARN2+ CLUSTER ION IN CHARGE-TRANSFER REACTIONS AT THERMAL ENERGIES

In order to examine the influence of neutral reagents on the effective recombination energy of a simple cluster ion in charge-transfer (CT) reactions at thermal energy, CT reactions of ArN2+ with CH 3Cl, CH2Cl2, CO2, and Kr are studied at near-thermal energy by using an ion-beam apparatus. Only CT channels leading to parent ion and/or fragment ions are found for all reagents. The reaction rate constants are (0.72-1.4)×10-9 cm3 s -1, which correspond to 55%-230% of the calculated values from Langevin or averaged dipole oriented theory. The effective recombination energy of ArN2+ in the CT reactions is found to depend on the ionization potentials of reagents. For CH3Cl and CH 2Cl2 with lower ionization potentials of 11.27 and 11.35 eV than the effective recombination energy of ArN2 +(∼13.5 eV), respectively, CT reactions occur without distortion of ArN2+. On the other hand, for CO2 and Kr with slightly higher ionization potentials of 13.78 and 14.00 eV than that, respectively, the bond length of (Ar-N2)+ slightly expands due to interactions with the reagent to increase the effective recombination energy of ArN2+ and to induce CT reaction. © 1995 American Institute of Physics.