The fragmentation of metastable NH+3 ions and isotopic analogs: an example of tunneling through a rotational barrier

Abstract

The fragmentation of metastable NH+3 ions and isotopic analogs via the reaction NH+3 → NH+2 + H has been investigated using mass analysed ion kinetic energy spectrometry (MIKES). Kinetic energy release distributions and the metastable intensity were measured as a function of ion source temperature. Both the average kinetic energy release and the metastable intensity increase with ion source temperature. The data are consistent with the metastable reaction arising from tunneling through a rotational barrier. The experimental data are compared with the predictions of a tunneling model.