title: Carboxylate binding in polar solvents using pyridylguanidinium salts.
abstract: A series of thiourea and guanidinium derivatives have been prepared and their ability to bind a carboxylate group has been investigated. Guanidinium 33, featuring two additional amides and a pyridine moiety, proved to be the most potent carboxylate binding site and was able to bind acetate in aqueous solvent systems (K(ass) = 480 M(-1) in 30% H(2)O-DMSO). The pyridine moiety is critical to obtaining strong binding, and comparison with the binding properties of analogous compounds in which the pyridine is replaced by a benzene ring provides a striking example of enthalpy-entropy compensation.
authors.affiliation: School of Chemistry, University of Southampton, Southampton, UK SO17 1BJ.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Fitzmaurice
authors.forename: Francesca
authors.initials: F
authors.lastname: Gaggini
authors.forename: Natarajan
authors.initials: N
authors.lastname: Srinivasan
authors.forename: Jeremy D
authors.initials: JD
authors.lastname: Kilburn
mesh_terms: D002264:Carboxylic Acids / Q000737:chemistry*; D004121:Dimethyl Sulfoxide; D019791:Guanidine / Q000138:chemical synthesis / Q000737:chemistry*; D012492:Salts / Q000138:chemical synthesis / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry*; D013890:Thiourea / Q000138:chemical synthesis / Q000737:chemistry
chemical_list: D002264:Carboxylic Acids; D012492:Salts; D012997:Solvents; D013890:Thiourea; D019791:Guanidine; D004121:Dimethyl Sulfoxide