Properties of phthalocyanine dyads with N2@C60, CO@C60 and H2O@C60 endohedral fullerenes: An insight from density functional theory calculations

Abstract

Density functional theory (DFT) calculations at the PBE-D2/DNP theoretical level were employed to study the bonding strength, geometries and some electronic properties of the dyads of phthalocyanines (MPcs, where M = 2H, Mn, Fe, Co, Ni, Cu, Zn) with N2@C60, CO@C60 and H2O@C60 endohedral fullerenes (EFs). All MPcs form stable complexes, where the binding energies span from −31.1 to −14.4 kcal/mol. The bonding pattern depends on the central atom, but not on the endohedral species. The charge transfer is always from MPc to EF. The common frontier orbital distribution, when HOMO is found totally on phthalocyanine molecule, whereas LUMO, on fullerene component, fulfills for most dyads, with the exception of MnPc-derived dyads, where both HOMO and LUMO are found completely on phthalocyanine system. The spin distribution and transfer within the systems incorporating open-shell phthalocyanine complexes (M = Mn, Co, Cu) strongly depends on the particular paramagnetic atom.