Carboxylate binding in polar solvents using pyridylguanidinium salts.
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.
Fitzmaurice
Richard J
RJ
School of Chemistry, University of Southampton, Southampton, UK SO17 1BJ.
Gaggini
Francesca
F
Srinivasan
Natarajan
N
Kilburn
Jeremy D
JD
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
D002264:Carboxylic Acids; D012492:Salts; D012997:Solvents; D013890:Thiourea; D019791:Guanidine; D004121:Dimethyl Sulfoxide