Alkali Metal Sensing with a Fluorescent 5,11,17,23-Tetraphenylcalix(4)arene and the Mechanism of the Fluorescence Change.

The fluorescence intensity of a tetraester derivative of the title compound increases markedly upon the Na+-binding. Hence, this is useful as a new, convenient Na+-sensing system. The mechanism of the fluorescence increase is discussed by comparing the fluorescence properties of several reference compounds.