pH-responsive molecular assemblies of pyridylbutadiene derivative with cucurbit[7]uril.

The interaction between red-emitting pyridinium derivative [4-((1,3)-4-(4-(dimethylamino)phenyl)buta-1,3-dien-1-yl)-1-methylpyridin-1-ium] (DABP) and cucurbit[7]uril was investigated using optical absorption, steady-state and time-resolved fluorescence and anisotropy measurements. The changes in the UV/Vis absorption, fluorescence spectral characteristics and lifetime, with a change in pH, reveal efficient binding of CB7 to the dye molecule. The cucurbit[7]uril encapsulated DABP brings ∼1.

Occurrence and fate of parabens and their metabolites in five sewage treatment plants in India.

Parabens (p-hydroxy benzoic acid esters) are antimicrobial agents, used widely as preservatives in personal care products (PCPs), pharmaceuticals, foods, and beverages. PCPs that contain parabens are a major source of these chemicals in sewage treatment plants (STPs). Very few studies have demonstrated the occurrence of parabens in wastewater.

Neutral and cationic pyridylbutadienes: solvatochromism and fluorescence response with sodium cholate.

Neutral and cationic diarylbutadienes with pyridine and pyridinium groups as electron acceptors with dimethylamine and diphenylamine as electron donors were synthesized. The absorption and emission properties of these dienes were investigated in homogeneous organic solvents and in sodium cholate media. In strongly polar solvents, both neutral and cationic fluorophores exhibit a bathochromic shift of emission characteristics of intramolecular charge transfer (ICT) excited states.