Jump to main content
Jump to site search

Issue 23, 2013
Previous Article Next Article

Anion capture and sensing with cationic boranes: on the synergy of Coulombic effects and onium ion-centred Lewis acidity

Author affiliations

Abstract

Stimulated by the growing importance and recognized toxicity of anions such as fluoride, cyanide and azides, we have, in the past few years, developed a family of Lewis acidic triarylboranes that can be used for the complexation of these anions in organic and protic solvents, including water. A central aspect of our approach lies in the decoration of the boranes with peripheral ammonium, phosphonium, sulfonium stibonium or telluronium groups. The presence of these cationic groups provides a Coulombic drive for the capture of the anion, leading to boranes that can be used in aqueous solutions where anion hydration and/or protonation are usually competitive. The anion affinity of these boranes can be markedly enhanced by narrowing the separation between the anion binding site (i.e. the boron atom) and the onium ion. In such systems, the latent Lewis acidity of the onium ion also plays a role as manifested by the formation of B–X→E (E = P, S, Sb, or Te; X = F, CN or N3) chelate motifs that provide additional stability to the resulting complexes. These effects, which are maximum in stibonium and telluronium boranes, show that the Lewis acidity of heavy onium ions can be exploited for anion coordination and capture. The significance of these advances is illustrated by the development of applications in anion sensing, fluorination chemistry and 18F radiolabeling for positron emission tomography.

Graphical abstract: Anion capture and sensing with cationic boranes: on the synergy of Coulombic effects and onium ion-centred Lewis acidity

Back to tab navigation

Publication details

The article was received on 22 Feb 2013, accepted on 29 Mar 2013 and first published on 03 Apr 2013


Article type: Perspective
DOI: 10.1039/C3DT50491C
Dalton Trans., 2013,42, 8164-8178

  •   Request permissions

    Anion capture and sensing with cationic boranes: on the synergy of Coulombic effects and onium ion-centred Lewis acidity

    H. Zhao, L. A. Leamer and F. P. Gabbaï, Dalton Trans., 2013, 42, 8164
    DOI: 10.1039/C3DT50491C

Search articles by author

Spotlight

Advertisements