Molecular recognition and scavenging of arsenate from aqueous solution using dimetallic receptors
Chris D Moffat1, Dominik J Weiss, Arun Shivalingam
1Department of Chemistry, Imperial College London, London SW7 2AZ (UK); Department of Earth Sciences and Engineering, Imperial College London, London SW7 2AZ (UK).
Abstract:
A series of copper(II), nickel(II) and zinc(II) dimetallic complexes were prepared and their affinities towards arsenate investigated. Indicator displacement assays (IDAs) were carried out to establish the complexes with best affinities towards arsenate. A di-zinc complex (3) was selected and its arsenate-binding abilities investigated by isothermal titration calorimetry (ITC). The X-ray crystal structure of this metallo-receptor bound to arsenate is also reported, which allowed us to establish the binding mode between 3 and this oxyanion. Immobilising 3 onto HypoGel resin yielded a novel adsorbent (Zn-HypoGel) with high affinity for arsenate. Adsorption of arsenate from competitive solutions and natural groundwater was greater than that of the commercially used iron oxide Bayoxide E33. Zn-HypoGel could be efficiently and simply regenerated by washing with sodium acetate solution.
Related Concept Videos
Extraction: Advanced Methods
Metal-Ligand Bonds
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
Complexation Equilibria: The Chelate Effect
EDTA: Chemistry and Properties
Masking and Demasking Agents
There are many masking agents, such as cyanide, fluoride, triethanolamine, thiourea, and 2,3-bis(sulfanyl)propan-1-ol (formerly 2,3-dimercapto-1-propanol), with the masking agent chosen based on...
Complexometric Titration: Ligands


