Understanding the relative binding ability of hydroxyfullerene to divalent and trivalent metals

Abstract

Metal contamination of water is a serious challenge faced by environmental chemists, but there is also economic value in the removal of metals for recycling or extraction. Our prior observation that hydroxyfullerenes [C60O(x)(OH)y](n-) act as chelate agents to Fe(3+) suggests that these material, or derivatives, may be used for co-precipitation. We report the removal of main group (Al(3+), Ag(+), Ca(2+), and Zn(2+)) as well transition metal (Fe(3+), Co(2+), Cu(2+), Mn(2+), and Ni(2+)) and lanthanide (La(3+) and Nd(3+)) ions from solution. The resulting complexes have been characterized by XPS, SEM, TEM, and DLS. The competitive binding with Fe(3+) shows that the binding affinity with hydroxyfullerenes follows the order: Zn(2+) > Co(2+) > Mn(2+) > Ni(2+) > La(3+) > Nd(3+) > Cd(2+) > Cu(2+) > Ag(+) > Ca(2+) > Fe(3+) > Al(3+). The relative binding ability is dependent on ionic radius; however, divergent trends are observed for M(2+) and M(3+), i.e., for divalent ions the binding is stronger for smaller ions, while the opposite trend is observed for trivalent ions. Previously the coordination of hydroxyfullerene to metals was assumed to be analogous to a 1,2-diol or catechol. However, while ab initio calculations using [M(catecholate)n](n-) (n = 2, 3) provide an explanation of the observed trend for M(2+), the use of cis-cis-1,3,5-cyclohexanetriol and cis-1,3-cyclohexanediol as model ligands provides insight into the relative binding efficiency for M(3+).

Fullerene-Directed Synthesis of Flowerlike Cu3(PO4)2 Crystals for Efficient Photocatalytic Degradation of Dyes

“…25 It is known that the hydroxyl groups of the fullerenol have properties similar to those of phenols and can interact with Cu 2+ ions through coordination. 32,33 A mechanism behind the formation of FLCs-Cu templated by fullerenol was then proposed, as illustrated in Scheme 2A. In brief, Cu 2+ accumulated on the surface of the fullerenol cluster at the initial stage through complexation with the hydroxyl groups.…”

A Multiparametric Study of Internalization of Fullerenol C60(OH)36 Nanoparticles into Peripheral Blood Mononuclear Cells: Cytotoxicity in Oxidative Stress Induced by Ionizing Radiation

“…However, depending on the research protocol applied, fullerenol may also act as prooxidant [53]. This dualistic nature of fullerenols may contribute to the future development of some new biomedical and environmental applications of these agents [54][55][56].…”

Magnetic and Biocompatible Fullerenol/Fe(III) Microcapsules with Antioxidant Activities

“…50 Because of the presence of a π-conjugated structure and a variety of hydroxyl groups, fullerenol exhibits properties similar to those of polyphenols and can form coordinate bonds with various metal ions including Fe 3+ . 52,53 These features of fullerenol encouraged us to explore the utilization of fullerenol in the preparation of metal-coordinated microcapsules. In this work, we show for the first time that fullerenol can accumulate onto the surfaces of polystyrene (PS) microspheres together with Fe 3+ , which was provided by acid etching of a rusty nail.…”