Highly Efficient and Selective Recognition of Dicyanoaurate(I) by a Bambusuril Macrocycle in Water

Angew Chem Int Ed Engl. 2022 Oct 24;61(43):e202210184. doi: 10.1002/anie.202210184. Epub 2022 Sep 21.

Abstract

Dicyanoaurate(I) anion, [Au(CN)2 ]- , plays a central role in the current industrial production of gold, as its extraction from crude ore samples represents the most money-consuming step. Herein, we present the strongest host-guest recognition of dicyanoaurate anion using the bambusuril receptor in water, a highly competitive solvent. The micromolar stability of such a complex facilitated the up to date most efficient supramolecular stripping of dicyanoaurate from activated carbon at ambient temperature. Thermodynamic characteristics of bambusuril binding with [Au(CN)2 ]- differing from binding of other inorganic chaotropic anions are rationalized, as well as the bambusuril selectivity for [Au(CN)2 ]- over [Ag(CN)2 ]- .

Keywords: Anion Binding; Bambusurils; Dicyanoaurate; Gold Extraction; Host-Guest Complexes.