Heavy N⁺ ion transfer in doubly charged N₂Ar van der Waals cluster.

Abstract

Van der Waals clusters are weakly bound atomic/molecular systems and are an important medium for understanding micro-environmental chemical phenomena in bio-systems. The presence of neighboring atoms may open channels otherwise forbidden in isolated atoms/molecules. In hydrogen-bond clusters, proton transfer plays a crucial role, which involves mass and charge migration over large distances within the cluster and results in its fragmentation. Here we report an exotic transfer channel involving a heavy N⁺ ion observed in a doubly charged cluster produced by 1 MeV Ne⁸⁺ ions: (N₂Ar)²⁺→N⁺+NAr⁺. The neighboring Ar atom decreases the [Formula: see text] barrier height and width, resulting in significant shorter lifetimes of the metastable molecular ion state [Formula: see text]([Formula: see text]). Consequently, the breakup of the covalent N⁺-N⁺ bond, the tunneling out of the N⁺ ion from the [Formula: see text] potential well, as well as the formation of an N-Ar⁺ bound system take place almost simultaneously, resulting in a Coulomb explosion of N⁺ and NAr⁺ ion pairs.