High quantum yield photoluminescence of new polyamides containing oligo-PPV amino derivatives and related oligomers

The synthesis and the chem. phys. characterization of new photoluminescent (PL) chromophores and polymers are reported. Chromophores (oligo-PPV sym. derivs. ending with amino groups) are strong blue emitters with a PL quantum yield of ∼70% in dioxane soln. They have been used to prep. polyamides by reaction with aliph. acyl dichlorides in which emitting and non emitting units are alternated. PL properties of the synthesized polyamides have been evaluated in soln. and reveal a strong blue emission (PL quantum yield ∼60%), to increase the soly. of these systems, oligomers have been purposely prepd. and then characterized. They show a peculiar white emission when excited in DMF soln.; to get insight into this interesting behavior, asym. monoacetylated chromophores have been prepd. as model compds. for the chromophoric end groups of the polyamide chains. The emission spectra of these compds. reveal a broad excimeric yellow emission which is responsible, along with the blue emission of the inner chromophoric units, of the overall white emission of the oligomers.