Photoinduced Extraction and Active Transport of Anions by a Triphenyl Methane Derivative

Abstract
Triphenylmethane derivative leukobase (1) was converted to its cation form 2 by UV irradiation. This lipophilic cation form was stable in dichloromethane with green color (λmax=634 nm), and returns to the original colorless form of 1 when shaked with an alkaline solution. Compound 2 exhibited excellent anion extraction ability (from aqueous solution into dichloromethane) under the conditions of appropriate pH, but 1 has no anion extraction ability. Photoinduced active transport of anions across a liquid (dichloromethane) membrane was achieved by using the difference in the extraction ability between 1 and 2 together with the difference in pH between the source and receiving phases.