Selective binding of cis-1,3,5-cyclohexane tricarboxylic acid vs its epimeric trans isomer by a tripodal amidopyridine receptor;: Crystal structures of the 1:1 complexes

[GRAPHICS] A tripodal tris-amidopyridine receptor forms a 1:1 complex with trans-1,3,5-cyclohexane tricarboxylic acid that is 1 order of magnitude less stable than the one formed with the corresponding cis-triacid epimer, The X-ray crystal structures of the complexes have been determined, confirming the binding geometry derived from NMR data in solution and force field calculations, and its geometrical features are used to explain the observed selectivity.