Cluster ion thermal decomposition (I): Experimental kinetics study and ab initio calculations for HSO4-(H2SO4)(x)(HNO3)(y)

Rate coefficients for the thermal decomposition of cluster ions of the type HSO4-(H2SO4), for x = 1-5, HSO4-(HNO3)(y) for y = 1, 2 and HSO4-H2SO4HNO3 were measured as functions of temperature and pressure in a quadrupole ion trap. The measured decomposition kinetics are in the low-pressure limit or in the fall-off re-ion between the low and high-pressure limits. Moments of inertia and vibrational frequencies of the clusters were obtained via ab i nitio HF/6-31+G(d) geometry optimizations. Bond energies were determined fr om analysis of the second-order rate coefficient data for the cluster ions with kinetics in the low-pressure limit. Upper limits of the bond energies were derived for the clusters with kinetics in the fall-off region.