Chiral recognition based on the kinetics of ion transfers across liquid/liquid interface
Résumé
Three-phase electrodes in combination with square-wave voltammetry are applied to study the transfer kinetics of chiral anions from water to the chiral 2-octanol. The experimental system used consists of a pyrolytic graphite electrode partly modified with a thin film of one of the enantiomers of 2-octanol, which was immersed into an aqueous solution containing anions of chiral 2-chloropropionic acid, 2- bromopropionic acid, or lactic acid. It is demonstrated that the kinetics of the ion transfer is a stereoselective. The rate of the ion transfer is higher when uncomplimentary transferring ion–solvent chiral isomers are used, i.e., (R)-ion and (S)-solvent, or (S)-ion and (R)-solvent. To the best of our knowledge this is the first evidence for the difference in the ion transfer kinetics of chiral isomers across water/chiral organic solvent interface.