Study of the reaction of N2+ with SO2 and its dependence on internal energy

The reaction of N2+ with SO2 has been studied in a tandem-ion cyclotron resonance mass spectrometer at less than 0.1 eV translational energy as a function of ion source pressure and collision chamber pressure. The internal energy state distribution of the N2+ reactant ions relaxes with increasing N2+/N2 collisions, producing a corresponding change in the branching ratio of the charge-transfer product SO2+ and the dissociative charge-transfer product SO+. With increasing SO2 pressure in the ICR cell, the dissociative charge-transfer channel is quenched. The total rate constant for charge-transfer was determined to be 7.0 x 10-10 cm3 molecule-1 sec-1; within experimental error, the rate constant is independent of the vibrational excitation of the N2+ ion