Novel luminescence dyes and ligands based on 4-hydroxythiazole

The condensation reaction of N-heteroaromatic nitriles with D,L-mercaptolactic acid results in the formation of 4-hydroxythiazoles. The products are sparingly soluble in most solvents in which they display only a weak fluorescence. However, upon derivatization of the OH-group by etherification, blue emitting luminescence dyes with high quantum yields and large stokes shifts were obtained. The luminescence of these thiazoles is affected by the 2-substituents and lies in the region of 410 nm, with quantum yields between 30% and 90%. Employing this method, not only new fluorophores were obtained, but also derivatives that offer good requirements for the construction of metal complexes due to their diazadiene substructure.