Issue 10, 2018

Toxic heavy metal – Pb, Cd, Sn – complexation by the octadentate hydroxypyridinonate ligand archetype 3,4,3-LI(1,2-HOPO)

Abstract

The toxicity of heavy metals such as lead (Pb), cadmium (Cd) and tin (Sn) has long been known but accidental exposures of large populations to these elements remain unfortunately a topical issue. Chelating agents against Pb, Cd, or Sn poisoning are still limited to classical ligands such as ethylenediamine tetraacetic acid (EDTA). Here, we evaluate the ability of 3,4,3-LI(1,2-HOPO) (L4−), an octadentate ligand currently under evaluation for actinide decorporation, to bind Pb, Cd and Sn metal ions in aqueous solutions. This ligand forms 1 : 1 complexes with Pb(II), Cd(II) and Sn(IV) as well as bimetallic 2 : 1 species with Pb(II) and Cd(II), all of which were characterized by high resolution mass spectrometry and spectrophotometric titrations. The 3,4,3-LI(1,2-HOPO) ligand exhibits an extreme affinity for Sn(IV) ions (log β110 > 40), with the complex remaining stable from highly acidic conditions to alkaline media (from 3 M HCl to pH 8). Single crystals of the neutral complex [SnIV3,4,3-LI(1,2-HOPO)·3H2O] were obtained and its structure determined, revealing a chiral conformation. Although not initially designed for hexacoordinated metals such as Pb(II) and Cd(II), the octadentate ligand shows promise for the in vitro or in vivo sequestration of toxic heavy metals, as evidenced by decorporation experiments performed in mice contaminated with 210Pb(II) and treated with either EDTA or 3,4,3-LI(1,2-HOPO).

Graphical abstract: Toxic heavy metal – Pb, Cd, Sn – complexation by the octadentate hydroxypyridinonate ligand archetype 3,4,3-LI(1,2-HOPO)

Supplementary files

Article information

Article type
Paper
Submitted
22 Pun 2017
Accepted
25 Phe 2018
First published
02 Kol 2018

New J. Chem., 2018,42, 7649-7658

Toxic heavy metal – Pb, Cd, Sn – complexation by the octadentate hydroxypyridinonate ligand archetype 3,4,3-LI(1,2-HOPO)

G. J.-P. Deblonde, T. D. Lohrey, D. D. An and R. J. Abergel, New J. Chem., 2018, 42, 7649 DOI: 10.1039/C7NJ04559J

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements