THE EFFECT OF CLUSTERING ON MUTUAL NEUTRALIZATION RATES USING ELECTROSTATICALLY MERGED ION-BEAMS - H3O-3)+OH-(H20)(M=0-3)((H2O)(N=0)

Relative rate constants for the mutual neutralization of hydrated hydr onium and hydrated hydroxide cluster ions have been measured using a n ew ion optical method which merges mass-selected beams of oppositely c harged cluster ions with an electrostatic quadrupole deflector. Measur ements are presented for all combinations of the reaction, H3O+(H2O)(n =0-3) + OH-(H2O)(m)=(0-3), under one ion optical setting of the intera ction region (different relative velocities) and a few representative reactions as a function of relative velocity. A pronounced enhancement in the relative rate constant is seen with clustering which suggests that cluster specific rate constants may be required for accurate chem ical modeling of the D region of the ionosphere. The neutralization re action mechanism changes dramatically with clustering which is interpr eted as st change from electron transfer at small cluster size to prot on transfer with more clustering.