title: Molecular recognition and scavenging of arsenate from aqueous solution using dimetallic receptors.
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.
authors.affiliation: Department of Chemistry, Imperial College London, London SW7 2AZ (UK); Department of Earth Sciences and Engineering, Imperial College London, London SW7 2AZ (UK).
authors.forename: Chris D
authors.initials: CD
authors.lastname: Moffat
authors.forename: Dominik J
authors.initials: DJ
authors.lastname: Weiss
authors.forename: Arun
authors.initials: A
authors.lastname: Shivalingam
authors.forename: Andrew J P
authors.initials: AJ
authors.lastname: White
authors.forename: Pascal
authors.initials: P
authors.lastname: Salaün
authors.forename: Ramon
authors.initials: R
authors.lastname: Vilar
mesh_terms: D000327:Adsorption; D001149:Arsenates / Q000737:chemistry* / Q000302:isolation & purification*; D018360:Crystallography, X-Ray; D006863:Hydrogen-Ion Concentration; D009942:Organometallic Compounds / Q000737:chemistry*; D019346:Sodium Acetate / Q000737:chemistry*; D012996:Solutions; D014874:Water Pollutants, Chemical / Q000737:chemistry* / Q000302:isolation & purification*; D018508:Water Purification; D015032:Zinc / Q000737:chemistry*
chemical_list: D001149:Arsenates; D009942:Organometallic Compounds; D012996:Solutions; D014874:Water Pollutants, Chemical; D019346:Sodium Acetate; D015032:Zinc
keywords: adsorption; arsenic; dimetallic receptors; heavy metals