Computational study of the complexation of metals ions with poly(amidoamine) PAMAM G0 dendrimers

In this study, a structural and thermodynamical characterization of the complexation process of amine-terminated PAMAM G0 dendrimer with metal ions, commonly present in wastewater, was carried out using computational chemistry approaches. Relevant information about the geometry, charge distribution and affinity of metal cations confirmed that, in a tetragonal field, the most stable coordination site corresponds to the core of the dendrimer. This interaction is established via the tertiary nitrogen of the ethylenediamine core and oxygen atoms belonging to the carbonyl site of the amide groups. Independently of the PAMAM G0 fragment or coordination site, the binding energy of the metal ions exhibited the following trend Cu(II) > Ni(II) > Zn(II), which is in agreement with previous experimental studies.