Novel polymerizable light emitting dyes – combination of a hindered amine with a 9-phenylxanthene fluorophore. Synthesis and photophysical investigations

The synthesis of new 9-phenylxanthene dyes, containing hindered amine stabilizer fragment is reported. Two polymerizable dyes, a combination of Fluorescein or Eosin with 2,2,6,6-tetramethylpiperidine, as well as two 9-phenylxanthene intermediates were synthesized in good yields under variable reaction conditions. Their light absorption and fluorescence properties in solution have been determined and discussed. Photooxidative stability of the new fluorophores has been studied and compared to other similar fluorescent dyes, not containing hindered amine fragment in their molecules. It was shown that the presence of a HALS (hindered amine light stabilizer) fragment in the dyes' molecules improved their photostability. The ability of the dyes to co-polymerize with vinyl monomers such as methyl methacrylate was demonstrated.