Theoretical investigation of rare gas hydride cations: HRgN 2 + (Rg=He, Ar, Kr, and Xe)

Rare gas containing protonated nitrogen cations, HRgN 2 + (Rg=He, Ar, Kr, and Xe), have been predicted using quantum computational methods. HRgN 2 + ions exhibit linear structure (C ∞v symmetry) at the minima and show planar structure (C s symmetry) at the transition state. The stability is determined by computing the energy differences between the predicted ions and its various unimolecular dissociation products. Analysis of energy diagram indicates that HXeN 2 + is thermodynamically stable with respect to dissociated products while HHeN 2 + , HArN 2 + , and HKrN 2 + ions are metastable with small barrier heights. Moreover, the computed intrinsic reaction coordinate analysis also confirms that the minima and the 2-body global dissociation products are connected through transition states for the metastable ions. The coupled-cluster theory computed dissociation energies corresponding to the 2-body dissociation (HN 2 + + Rg) is −288.4, −98.3, −21.5, and 41.4 kJ mol −1 for HHeN 2 + , HArN 2 + , HKrN 2 + , and HXeN 2 + ions, respectively. The dissociation energies are positive for all the other channels implying that the predicted ions are stable with respect to other 2- and 3-body dissociation channels. Atoms-in-molecules analysis indicates that predicted ions may be best described as HRg + N 2 . It should be noted that the energetic of HXeN 2 + ion is comparable to that of the experimentally observed stable mixed cations, viz. (RgHRg ′ ) + . Therefore, it may be possible to prepare and characterize HXeN 2 + ions in an electron bombardment matrix isolation technique.