Selective binding behaviors of p-sulfonatocalixarenes in aqueous solution

The complex structures, binding abilities, molecular selectivities, and thermodynamic origin of p-sulfonatocalixarenes upon complexation with kinds of guests are outlined in this review article, including inorganic cations, organic ammonium cations, pyridiniums and viologens, neutral organic molecules, dye molecules, and others. Calorimetric and spectroscopic investigations afford the complex stability constants, thermodynamic parameters and binding manners of the inclusion complexation of p-sulfonatocalixarenes with guest molecules. The pi-stacking, hydrophobic and charge interactions are the main driving-forces during the course of the host-guest inclusion complexation. The molecular binding abilities and selectivities are influenced by not only the frameworks of calixarene cavities, structures of guest molecules, and their binding manners but also the conditions of solutions (mainly pH), which are discussed from the correlation between the structural features and molecular-recognition abilities. Moreover, the further applications and potentials of p-sulfonatocalixarenes are briefly described.