Small Molecules as Long-Wavelength Fluorophores: Push-Pull Substituted 4-Alkoxy-1,3-thiazoles

A series of donor-π-acceptor (D-π-A) substituted 4-hydroxythiazoles have been synthesized. Electron-donating groups (4-methoxyphenyl and 4-dimethylaminophenyl) were installed in the 5-position of the thiazole; thiophene/pyridine-bridged acceptors (formyl groups and their Knoevenagel condensation products) were placed in the 2-position. The influence of D-π-A character on the photophysical properties and electronic structure was investigated by means of UV/Vis and fluorescence spectroscopy.