Determination of quenching inhibition factor and selective fluorescence quenching study of perylene, pyrene and fluoranthene in micelle by cetyl pyridinium chloride as a hydrophobic quencher molecule

The fluorescence quenching study of perylene, pyrene and fluoranthene by ce tyl pyridinium chloride (CPC) a hydrophobic quencher molecule has been carr ied out using synchronous fluorescence scan. A quenching inhibition factor (QIF) has been defined for added quencher in inert micellar medium. The oth er quenching parameters calculated are K-Q and E-Q. The obtained quenching parameter QIF well compares with these values. The quenching mechanism is f ound to be explainable by a quencher sphere of action model. In micellar me dium the fluorescence quenching efficiency is in the order: pyrene > peryle ne > fluoranthene. A correlation between alternate and non-alternate PAHs a nd aromatic ring size with QIF has been reported for CPC in micelle.