Kinetic and equilibrium studies of ion association reaction between dye ions and hydrophobic counter ions accompanied by the change in light-absorbing and fluorescent characteristics

点击翻译按钮获取中文摘要

1. Four principles of characteristic light-absorption and fluorescence changes accompanied by ion association between dye ions and hydrophobic counter ions in an aqueous medium were found. To clarify the changes in characteristic light-absorption and establish useful color reactions based on ion associates, novel ionic dyes were synthesized and examined.2. N,N-dialkylaminophenylazobenzenesulfonic acid and its derivatives were synthesized. Dibutyl derivatives were found to show the most effective blue shift, when they formed ion associates with hydrophobic cations. This phenomena was useful in the absorptiometric determination of cationic and anionic surfactants in aqueous mediums. Derivatives of phenylazophenol were examined. These dyes showed a red shift and molar absorptivities became larger, when the polarity of a medium changed from polar to less polar. Novel anionic triphenylmethane dyes were synthesized. They were very stable even in an alkaline medium. In a weakly acidic medium, … More the electrically neutral species reacted with a hydrophobic cations to form colored ion associates. This color relation was favorably applied to the photometric titration of ionic surfactants as an indicator.3. Characteristics and behavior of triphenylmethane dyes in an aqueous medium were examined by a stopped-flow method. All rate and equilibrium constants were determined for five representative dyes. Halogeno derivatives of Malachite Green and Brilliant Green were newly synthesized and examined. These dyes were less hydrated and more hydrophobic. The monochloro derivative of MG was preferably used for the ion association with heteropolyacid. Dialkylaminophenylazopyridine derivatives were synthesized and examined. These dyes reacted with hydrophobic anions (A^-) to form ion associates (HD^+ ・ A^-). Dialkylaminophenylazo-N-alkyl- pyridinium salts was also synthesized and examined. In an acidic medium, the dyes were present in a protonated form(HD^<2+>), which reacted with hydrophobic anions(A^-) to form ion associates (D^+ ・ A^-), followed by the color change from yellow to reddish violet. Less