DYNAMIC SOLVATION EFFECTS IN I-2(-)(CO2)(N) IMPACT ONTO SOLID-SURFACE- WEDGE AND CAGE EFFECTS

Novel mechanisms were found to operate in dissociation of I-2(-) embed ded in a CO2 cluster, I-2(-)(CO2)(n), by its impact onto a silicon sur face. The bond of I-2(-) is split by a CO2 molecule located halfway be tween the two iodine atoms in the parent I-2(-)(CO2)(n), as if the CO2 molecule behaves as a molecular 'wedge' (wedge effect). On the other hand, the dissociation of I-2(-) is suppressed when it is caged in a c omplete CO2 molecular shell (cage effect). The wedge effect was also d emonstrated by By measuring the surface-parallel component of the tran slational energy of the I-2(-) and I- that a 'quasi-equilibrium' was e stablished on the surface before the product anions leave distribution of the product anions also shows the cage effect.