Aggregation behaviors of light-active barbituric acid molecular componentsin solution

Self-aggregation of light active barbituric acid derivatives and their self -assembly with melamine derivatives through hydrogen-bonding, pi-aromatic s tacking, 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. AB( 12) and AB(1) lead to different degrees of fluorescence splitting. When bar bituric acid molecular components were self-assembled with melamine a simil ar splitting phenomenon was observed. It was shown that pi-aromatic stackin g resulted in the exclusive fluorescence changes and H-aggregates were form ed in solution. (C) 1998 Elsevier Science Limited. All rights reserved.