Studies of the reactivity of carbon nanotubes towards selected alkali cations and chlorides based on the HSAB theory

Polycyclic curved aromatic fragments (C24H12) have been employed as models of SWNTs ((n,0), where n varies from 4 up to 30) in order to investigate the relation between the curvature and reactivity of the sidewalls. The flat coronene structure has been chosen as a molecular fragment topologically resembling the honeycomb lattice, and it is treated as the reference one. The intrinsic chemical reactivity in terms of the Fukui function, applying the principle of hard and soft acids and bases (HSAB) in the framework of the density functional theory (DFT), was investigated. In the current study we take into account the interactions of hard acids (Li+, Na+, and K+) and isoelectronic ions (F− and Cl−, hard bases), treated as the probe molecules, with the exterior surface of mentioned above structures. The linear correlations between the adsorbate–adsorbent interactions and the both total as well as local hardness and/or molecular energy potential for studied ions were observed (increasing reactivity upon increasing curvature). Obtained results illustrate that the HSAB parameters can be a good measure for the reactivity if the influence of geometrical changes is considered.