title: Anion Recognition by Aliphatic Helical Oligoureas.
abstract: Anion binding properties of neutral helical foldamers consisting of urea type units in their backbone have been investigated.1H NMR titration studies in various organic solvents including DMSO suggest that the interaction between aliphatic oligoureas and anions (CH3COO-, H2PO4-, Cl-) is site-specific, as it largely involves the urea NHs located at the terminal end of the helix (positive pole of the helix), which do not participate to the helical intramolecular hydrogen-bonding network. This mode of binding parallels that found in proteins in which anion-binding sites are frequently found at the N-terminus of an α-helix.1H NMR studies suggest that the helix of oligoureas remains largely folded upon anion binding, even in the presence of a large excess of the anion. This study points to potentially useful applications of oligourea helices for the selective recognition of small guest molecules.
authors.affiliation: Université de Bordeaux, UMR 5248 CBMN, Institut Européen de Chimie et Biologie, 2 rue Robert Escarpit, 33607, Pessac, France.|CNRS, UMR 5248 CBMN, 33607, Pessac, France.|UMR CNRS 8161, Pasteur Institute of Lille, Univ Lille, 1 rue du Professeur Calmette, 59021, Lille, France.
authors.forename: Vincent
authors.identifier: http://orcid.org/0000-0002-5735-4630
authors.initials: V
authors.lastname: Diemer
authors.affiliation: Université de Bordeaux, UMR 5248 CBMN, Institut Européen de Chimie et Biologie, 2 rue Robert Escarpit, 33607, Pessac, France.|CNRS, UMR 5248 CBMN, 33607, Pessac, France.
authors.forename: Lucile
authors.identifier: http://orcid.org/0000-0003-2648-793X
authors.initials: L
authors.lastname: Fischer
authors.affiliation: Université de Bordeaux, CNRS, UMS 3033, INSERM US001, Institut Européen de Chimie et de Biologie, 2 rue Robert Escarpit, 33607 Pessac, France.
authors.forename: Brice
authors.identifier: http://orcid.org/0000-0002-2932-3255
authors.initials: B
authors.lastname: Kauffmann
authors.affiliation: Université de Bordeaux, UMR 5248 CBMN, Institut Européen de Chimie et Biologie, 2 rue Robert Escarpit, 33607, Pessac, France. g.guichard@iecb.u-bordeaux.fr.|CNRS, UMR 5248 CBMN, 33607, Pessac, France. g.guichard@iecb.u-bordeaux.fr.
authors.forename: Gilles
authors.identifier: http://orcid.org/0000-0002-2584-7502
authors.initials: G
authors.lastname: Guichard
mesh_terms: D000838:Anions / Q000737:chemistry*; D002245:Carbon Dioxide / Q000737:chemistry*; D006860:Hydrogen Bonding; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D010455:Peptides / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry*; D014508:Urea / Q000737:chemistry*
chemical_list: D000838:Anions; D010455:Peptides; D012997:Solvents; D002245:Carbon Dioxide; C041069:carboxyl radical; D014508:Urea
keywords: X-ray diffraction; anions; foldamers; helical structures; oligourea