Aggregation behaviors of light-active barbituric acid molecular components in solution

Self-aggregation of light active barbituric acid derivatives and their self-assembly with melamine derivatives through hydrogen-bonding, π-aromatic stacking, and other weak interactions were studied by UV–visible absorption and fluorescence spectroscopy. PB₁₂Me has the same fluorescence behavior as PB₁₂ in chloroform though it cannot aggregate through a hydrogen-bond. AB₁₂ and AB₁ lead to different degrees of fluorescence splitting. When barbituric acid molecular components were self-assembled with melamine a similar splitting phenomenon was observed. It was shown that π-aromatic stacking resulted in the exclusive fluorescence changes and H-aggregates were formed in solution.