Synthesis and characterization of monoanionic salts of p-tertbutylcalix[7]arene

The synthesis and full characterization of a new series of p-tert-butylcalix [7]arene (tBuC7) monoanionsof the type tBuC7M (M Na, K, Rb, Cs) is reported. Crystal structures of tBuC7K and tBuC7Rb featuremonomeric units and represent the first examples of solid state characterized tBuC7 salts. The alkalimetal base strength and reaction stoichiometry used for the selective formation of monoanionic speciesis discussed.