Speciation, stability constants and structures of complexes of copper(II), nickel(II), silver(I) and mercury(II) with PAMAM dendrimer and related tetraamide ligands

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

“…This fact agrees with previous experimental [22,[24][25][26] and theoretical studies [42] which suggested that metal ions in a tetragonal field preferentially coordinate, in the case of low generations, to the core site of the dendrimer. This confirms that the most stable coordination occurs with the tertiary nitrogen sites of the ethylenediamine core and oxygen atoms belonging to the carbonyl site of the amide groups [44][45][46] forming a 4-membered ring.…”

“…Among literature there is no agreement about the chelating dendrimer atoms that participate in complexation with metal ions. Some authors identified amide nitrogen atoms [21][22][23][24] and other suggested that coordination to metal ions is preferred through the oxygen atoms belonging to the carbonyl site of the amide group [25,26]. In this sense, theoretical and computational studies could contribute to understand structural and electronic aspects of metal ion -PAMAM complexation, providing detailed information about the nature of the metal ion attachment to the dendrimer site.…”

Voltammetric Sensing of Mercury and Copper Cations at Poly(EDTA‐like) Film Modified Electrode

“…Such neutral ligand has been recently shown to be fully suited for the complexation of numerous metallic species to form monometallic octahedral complexes wherein both amines and four carbonyl functions are tightly bound to one divalent metal ion [66 -68]. The observation of signals whose mass correspond to partially deprotonated ligand is moreover in full agreement with previously reported speciation studies showing that such amide functions might be anionic at high pH values [68].…”

Synthesis of first- and second-generation imidazole-terminated POSS-core dendrimers and their pH responsive and coordination properties

“…Earlier studies that reported the d-d transition B700 nm indicated that the ligand is coordinated with two tertiary nitrogen atoms and two amide oxygen atoms in the equatorial plane and that one amide oxygen atom is axially coordinated. 22 To examine the coordination modes of the dendrimers with Cu 2+ ions, we performed spectrophotometric titration and kept the amount of Cu 2+ ions titrated into the solutions at 0.2 mM for POSS-Im16 and 0.1 mM for POSS-Im32. When the concentration ratio between POSS-Im16 and the Cu 2+ ions decreased, the positions of the absorption maxima shifted gradually from 604 nm to a longer wavelength at 763 nm (Figure 5a).…”