Amino acid binding in water by a new guanidiniocarbonyl pyrrole dication: the effect of the experimental conditions on complex stability and stoichiometry

The synthesis and binding properties of a new guanidiniocarbonyl pyrrole dication 2 are reported, which efficiently binds alanine carboxylate 7 in water with log Kass = 3.9. However, the experimental conditions for determining the binding constant significantly influence both complex stability and stoichiometry.