| Abstract: | The ligand calix4]pyrrole is quite insoluble in aqueous solution. In the presence of NaCl, KCl, CsCl, NH4Cl, CaCl2, and CdCl2, the solubility of calix4]pyrrole linearly increases with the salt concentration. The ligand calix4]pyrrole forms stable complexes with the chloride anion. All other halogen anions do not form complexes. The measurement of the amount of dissolved ligand allows the determination of the complex stabilities in aqueous solution. This experimental method is discussed in detail due to its general suitability to study the complexation reactions with nearly insoluble ligands. |
