OxH2x+1+ clusters: A new series of non-metallic superalkali cations by trapping H3O+ into water

We report a new series of non-metallic superalkali cations, OxH2x+1+ (x = 1–5) using ab initio MP2/6–311++G(d,p) level. These cations are designed by successive hydration of the hydronium cation (OH3+), which can be expressed in the form of OH3+ … (x-1)H2O complexes. These OxH2x+1+ clusters possess a number of electrostatic as well as partially covalent H-bonds, with the interacting energy in the range 5.2–29.3 kcal/mol as revealed by quantum theory of atoms in molecules analyses. These cations are found to be stable against deprotonation as well as dehydration pathways, and their stability increases with the increase in x. Interestingly, the vertical electron affinities (EAv) of OxH2x+1+ clusters decreases rapidly from 5.16 eV for x = 1–2.67 eV for x = 5, which suggest their superalkali nature. It is also possible to continue this series of non-metallic superalkali cations for x > 5 with even lower EAv, down to an approximated limit of 1.85 eV, which is obtained for OH3+ trapped into water cavity implicitly using polarizable continuum model. The findings of this study will establish the OxH2x+1+ clusters as a new series of superalkali cations, which can be exploited their interesting applications.Graphical abstract
Source: Journal of Molecular Graphics and Modelling - Category: Molecular Biology Source Type: research