Colorimetric sensor and inverse fluorescent behavior of anions by calix[4]arene possessing imidazo[4,5-f]-1,10-phenanthroline groups and its Ru(II) complex

摘要

A calix[4]arene derivative (1) possessing imidazo[4,5-f]-1,10-phenanthroline groups and its Ru(II) complex (2) have been prepared. The photophysical behavior and the binding ability of 1 and 2 with some anions were investigated by fluorescence spectrometry and H-1 NMR experiments. The complex stability constants (K-S) for the stoichiometric 1:1 complexation of 1 and 2 with the anions were obtained by the fluorimetric titrations, indicating that the binding abilities of both hosts for F- and AcO- are highest among all anions examined. Interestingly, compound 1 can be used as a colorimetric sensor to F- and AcO- due to anion-induced deprotonation of the NH group of the imidazole ring. In contrast, the addition of Cl-, Br-, I- and [image omitted] to the DMF solution of 2 enhances its relative emission intensity, while the addition of F- and AcO- quenches its fluorescence intensity.