Interaction of metal phthalocyanines with carbon zigzag and armchair nanotubes with different diameters

Quantum-chemical calculations of the association of metal free, cobalt, copper and zinc phthalocyanines (MPc) with carbon zigzag and armchair nanotubes (CNTs) with diameters in the range of 7–14 Å were carried out by the DFT method with the use of BH van der Waals density functional and DZP atomic basis set. It was shown that interaction energy between the phthalocyanine molecules and the CNTs, as a whole, increases with an increase of the diameter of carbon nanotubes. However, in the case of CNT(n,0) the energy reaches its maximal value at n = 16 or 17 depending on the central metal atom and phthalocyanine orientation on the carbon nanotubes surface. Up to diameter of 10.5 Å of the CNTs, stronger binding of the considered MPc macrocyclic molecules is observed with carbon armchair nanotubes. However, in the case of higher diameters the phthalocyanines are associated more strongly with the zigzag CNTs.