Anion binding in aqueous media by a tetra-triazolium macrocycle.
Nicholas G White, Sílvia Carvalho, Vítor Félix, Paul D Beer
Chemistry Research Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford, OX1 3TA, United Kingdom.
Organic & biomolecular chemistry 2012 Sep 14Three tetra-triazole macrocycles were synthesized in good yields by the copper(i)-catalysed cycloaddition of bis-triazole azides and bis-alkynes. One of these was alkylated to give a cyclic tetra-triazolium receptor, which complexes anions strongly in competitive DMSO-water mixtures. In 1 : 1 DMSO-water, the tetracationic receptor exhibits a preference for the larger halides, bromide and iodide, with all halides associating more strongly than the oxoanion, acetate. The sulfate dianion is complexed far more strongly than any of the monobasic anions (K(a) > 10(4) M(-1)). Quantum mechanics/molecular mechanics simulations corroborate the experimentally determined anion binding selectivity trends.
Citation
Nicholas G White, Sílvia Carvalho, Vítor Félix, Paul D Beer. Anion binding in aqueous media by a tetra-triazolium macrocycle. Organic & biomolecular chemistry. 2012 Sep 14;10(34):6951-9
PMID: 22829100
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