title: Anion and carboxylic acid binding to monotopic and ditopic amidopyridine macrocycles.
abstract: Binding of inorganic anions, carboxylic acids, and tetraalkylammonium carboxylates by macrocyclic compounds of different size was studied by NMR in DMSO-d6. It has been shown that at least a 15-membered ring is necessary for successful recognition of fluoride. Larger macrocycles were shown to bind HSO4(-), H2PO4(-), Cl(-), and carboxylic acid salts. Effects of binding topicity are discussed. The 30-membered macrocycles 4 and 4m selectively bind substrates that are size- and shape-complementary: maximum binding is observed for dicarboxylic acids and dicarboxylates with four-carbon chains, and the binding constant for association of fumaric acid and 4 is ca. 5 orders of magnitude higher than that of maleic acid. The 30-membered macrocycle 4m showed selectivity toward alpha-ketocarboxylic acids. Secondary amino groups were not crucial for binding of fluoride to the macrocycles; however, they proved to be very important for selectivity and strength of carboxylic acid binding. The X-ray structure of the adduct of 4 and nitrobenzoic acid confirmed the guest H-bonding with both the amide and the secondary amino groups of the 30-membered macrocyclic host.
authors.affiliation: Department of Chemistry, Tufts University, 62 Talbot Avenue, Medford, Massachusetts 02155, USA.
authors.forename: Ivan V
authors.initials: IV
authors.lastname: Korendovych
authors.forename: Mimi
authors.initials: M
authors.lastname: Cho
authors.forename: Olga V
authors.initials: OV
authors.lastname: Makhlynets
authors.forename: Phillip L
authors.initials: PL
authors.lastname: Butler
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Staples
authors.forename: Elena V
authors.initials: EV
authors.lastname: Rybak-Akimova
mesh_terms: D000632:Aminopyrine / Q000138:chemical synthesis*; D000838:Anions; D002264:Carboxylic Acids / Q000737:chemistry*; D047028:Macrocyclic Compounds / Q000138:chemical synthesis*; D008958:Models, Molecular; D015394:Molecular Structure
chemical_list: D000838:Anions; D002264:Carboxylic Acids; D047028:Macrocyclic Compounds; D000632:Aminopyrine