title: Anion binding in aqueous media by a tetra-triazolium macrocycle.
abstract: Three 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.
authors: Chemistry Research Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford, OX1 3TA, United Kingdom.
authors: Nicholas G
authors: NG
authors: White
authors: Sílvia
authors: S
authors: Carvalho
authors: Vítor
authors: V
authors: Félix
authors: Paul D
authors: PD
authors: Beer