Role of aromaticity and charge of a system in its hydrogen trapping potential and vice versa

Abstract

Hydrogen storage capacity of some Li⁺/F^- doped neutral and charged aromatic/antiaromatic systems is studied at the B3LYP, M05-2X, MPW1K and MP2 levels of theory. Various conceptual density functional theory based global and local reactivity descriptors, nucleus independent chemical shift (NICS), NICS-rate, interaction energy per H₂ molecule, reaction enthalpy and reaction electrophilicity are used for this purpose. It is observed that there is a direct bearing of the hydrogen adsorption capability on the aromaticity and/or the charge of the system (or the charge on a specific center). The latter quantities do also change on gradual hydrogen loading.