Kass-controlled Hg2+ transport from Crystal Violet Lactone to Fluoran

We have investigated the Hg2+ transport from Crystal Violet Lactone to Fluoran dye based on the association constant, Kass. Upon addition of Hg2+, the Crystal Violet Lactone shows a new peak at around 603 nm, and the color of the solution changed from colorless to blue. With the addition of Fluoran dye in this solution containing Crystal Violet Lactone and Hg2+, the absorption intensity of Fluoran dye at 447 nm and 586 nm was all increased. So the color of solution gradually became black from blue color. From the changes of the ratio A586/A447, it is apparent that the Hg2+ in Crystal Violet Lactone–Hg2+ was transported to colored Fluoran. The Hg2+ transport from Crystal Violet Lactone to Fluoran dye was also carried out by the calculation of the association constant: the binding ability for the complex formation of Fluoran dye and Crystal Violet Lactone–Hg2+ is much greater in CH3CN solution (Kass = 3.0 × 104 M−1) than that of the Crystal Violet Lactone with Hg2+ (Kass = 1.2 × 103 M−1).

► The Hg2+ transport from CVL to Fluoran dye based on the Kass was investigated.
► With addition of Fluoran in CVL–Hg2+, the absorbance at 447 and 586 nm was increased.
► The Hg2+ transport from CVL to Fluoran was performed by the calculation of the Kass.