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Abstract: Five new complex salts [Pt(SC(NH2)2)4][dc] (dc=adipate (1), isophthalate (2), terephthalate (3), 4,4′-biphenyldicarboxylate (4), 1,4-naphthalenedicarboxylate (5)) have been characterized by single-crystal X-ray diffraction. Thiourea–carboxylate interactions have proven to be a reliable supramolecular synthon, yielding in all the examples charge-assisted hydrogen-bonded 3D networks via N–H⋯O interactions. [Copyright &y& Elsevier]

The cis coordination of two 3,5-di-nbutylamidopyridine ligands to a [Pt(4,4′-tBu-2,2′-bipy)]2+ fragment (with non-coordinating PF6- anions) generated a square planar complex with four amido groups capable of hydrogen bonding to guest anions. 1H NMR spectroscopy was used to evaluate binding of the oxoanions NO3−, ReO4−, CF3SO3−, H2PO4−, HSO4−, CH3COO− and C6H5COO− to the receptor. An X-ray crystal structure of the NO3− adduct showed details of the receptor-substrate interaction and provided an explanation as to why this receptor was not an improvement over a previously reported tetrakis(nicotinamide) complex of Pt(II) which was shown to be selective for nitrate and acetate ions. [Copyright &y& Elsevier]

3,4-Diphenylfuran-2,5-dicarboxylic acid bis-N-phenylamide 1 and 3,4-biphenyl-furan-2,5-dicarboxylic acid bis-N-butylamide 2 have been synthesised and shown to act as fluoride selective anion receptors in DMSO-d6/0.5% water solution. [Copyright &y& Elsevier]

The crystal structure of the tetrabutylammonium benzoate complex of 3,4-diphenyl-1H-pyrrole-2,5-dicarboxylic acid bis-butylamide has been elucidated confirming the formation of a cleft conformation in the solid state upon anion binding. [Copyright &y& Elsevier]

The ability of pyrrole-containing species to form higher order self-assembled ensembles and aggregates in the solid state is reviewed. The different binding modes pyrrole adopts in stabilizing these systems are analyzed as are the various underlying hydrogen bonding interactions upon which they are predicated. [Copyright &y& Elsevier]

Four amido-pyrrole cleft anion receptors bearing one or two ferrocene reporter groups have been synthesised and crystallographically characterised. The receptors contain either a non-conjugated (1 and 3) or conjugated (2 and 4) link between the anion binding amido-pyrrole unit and the ferrocene reporter groups. The anion binding affinities and electrochemical behaviour of the receptors in the absence and presence of anions have been studied by 1H NMR titration techniques and cyclic voltammetry using a Pt microdisc working electrode, respectively. [Copyright &y& Elsevier]

Abstract: The interactions of a series of urea-based anion receptors and alkylcarbamate species formed by the reaction of carbon dioxide with primary amines have been investigated by 1H NMR. Significant downfield shifts in the NH proton signals of the receptors in the presence of the alkylcarbamates were observed, consistent with classical host:anion hydrogen-bonding. This observation demonstrates that neutral hydrogen bond donor receptors can compete with ammonium cations to bind carbamates in DMSO-d 6 solution. [Copyright &y& Elsevier]

Phenylthiosemicarbazones (PTSCs) are proton-coupled anion transporters with pH-switchable behaviour known to be regulated by an imine protonation equilibrium. Previously, chloride/nitrate exchange by PTSCs was found to be inactive at pH 7.2 due to locking of the thiourea anion binding site by an intramolecular hydrogen bond, and switched ON upon imine protonation at pH 4.5. The rate-determining process of the pH switch, however, was not examined. We here develop a new series of PTSCs and demonstrate their conformational behaviour by X-ray crystallographic analysis and pH-switchable anion transport properties by liposomal assays. We report the surprising finding that the protonated PTSCs are extremely selective for halides over oxyanions in membrane transport. Owing to the high chloride over nitrate selectivity, the pH-dependent chloride/nitrate exchange of PTSCs originates from the rate-limiting nitrate transport process being inhibited at neutral pH. [Display omitted] • A new class of phenylthiosemicarbazones (PTSCs) function as pH-switchable transmembrane anion transporters. • Chloride/nitrate exchange is switched OFF at pH 7.2 due to an intramolecular hydrogen bond and ON at pH 4.5. • Anion transport selectivity analysis reveals strong halide over oxyanion preference exhibited by protonated PTSCs. • The pH-switchable chloride/nitrate exchange originates from inhibition of rate-limiting nitrate transport at pH 7.2. [ABSTRACT FROM AUTHOR]