Light-harvesting of polymerizable 4-hydroxy-1,3-thiazole monomers by energy transfer toward photoactive Os(II) metal complexes in linear polymers

A polymer library consisting of a series of three fluorescing monomers (i.e., blue, yellow and redemitting) based on 4-hydroxy-1,3-thiazole chromophores as well as an Os(II) metal complex containing monomer was synthesized. These materials were characterized using 1H NMR spectroscopy, size exclusion chromatography (SEC) as well as TGA and DSC measurements. The optical properties were investigated utilizing UV-vis absorption and emission measurements. The tailor-made optical properties of the monomer units facilitate an energy transfer from the blue over the yellow and red chromophore to the photoactive Os(II) polypyridyl moiety. For this purpose, the energy transfer was monitored using excitation-emission correlation spectroscopy.