Bis(4-hydroxythiazoles): Novel Functional and Switchable Fluorophores

Abstract

A series of 2,2′- and 5,5′-bis(4-hydroxythiazoles) was synthesized according to Hantzsch synthesis. Both phenols and their corresponding anions display a strong fluorescence in the visible spectrum, whereas the emission is shifted bathochromically upon deprotonation. This easy switch makes them suitable for widespread applications, mainly in analysis and supramolecular chemistry. Due to their 1,4-diazadiene substructure, the 2,2′-bithiazoles possess prerequisites for the complexation of metals, however, instead of a copper complex, a dimer which constitutes the 5,5′-C-C coupled product was isolated. In addition, tris(thiazoles) could be constructed.