Premium
Selective Separation of Hexachloroplatinate(IV) Dianions Based on Exo‐Binding with Cucurbit[6]uril
Author(s) -
Wu Huang,
Wang Yu,
Jones Leighton O.,
Liu Wenqi,
Zhang Long,
Song Bo,
Chen XiaoYang,
Stern Charlotte L.,
Schatz George C.,
Stoddart J. Fraser
Publication year - 2021
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.202104646
Subject(s) - supramolecular chemistry , chemistry , cucurbituril , platinum , hydrogen bond , molecular recognition , metal ions in aqueous solution , non covalent interactions , catalysis , metal , combinatorial chemistry , stereochemistry , crystallography , medicinal chemistry , molecule , organic chemistry , crystal structure
The recognition and separation of anions attracts attention from chemists, materials scientists, and engineers. Employing exo‐binding of artificial macrocycles to selectively recognize anions remains a challenge in supramolecular chemistry. We report the instantaneous co‐crystallization and concomitant co‐precipitation between [PtCl 6 ] 2− dianions and cucurbit[6]uril, which relies on the selective recognition of these dianions through noncovalent bonding interactions on the outer surface of cucurbit[6]uril. The selective [PtCl 6 ] 2− dianion recognition is driven by weak [Pt−Cl⋅⋅⋅H−C] hydrogen bonding and [Pt−Cl⋅⋅⋅C=O] ion–dipole interactions. The synthetic protocol is highly selective. Recognition is not observed in combinations between cucurbit[6]uril and six other Pt‐ and Pd‐ or Rh‐based chloride anions. We also demonstrated that cucurbit[6]uril is able to separate selectively [PtCl 6 ] 2− dianions from a mixture of [PtCl 6 ] 2− , [PdCl 4 ] 2− , and [RhCl 6 ] 3− anions. This protocol could be exploited to recover platinum from spent vehicular three‐way catalytic converters and other platinum‐bearing metal waste.