Discrimination and Asymmetric Induction with Chiral Polyanilines

CHIRAL DISCRIMINATION AND ASYMMETRIC INDUCTION WITH CHIRAL POLYANILINES 

Kaner and coworkers84 85 have recently reported enantiomeric discrimination of amino acids by chiral PAn films. The EB form of PAn doped with (.S )-(+)- or (/ )-(—)-10-camphorsulfonic acid was used to separate racemates of DL-amino acids. The interactions of the chiral PAn films with amino acids suggested that the chiral recognition ability of dedoped PAn is size and shape dependent. These properties may be useful in the employment of chiral PAn as a chiral stationary phase for chromatography. 

A striking example of asymmetric induction by chiral PAn s has been the recent demonstration that thin optically active PAn film layers can act as platforms to induce optical activity in PAn s containing only achiral dopants that are subsequently elec-trochemically deposited on these surfaces.86 The origin of this remarkable macromo-lecular asymmetric induction is currently uncertain. Interestingly, Samuelson and coworkers87 have recently observed related asymmetric induction in the horseradish peroxidase catalyzed synthesis of PAn/(+)-HCSA/PAA, PAn/(-)-HCSA/PAA and PAn/(rac)-HCSA/PAA nanocomposites (PAA = polyacrylic acid), where the PAn chains adopted the same helical hand, irrespective of the hand of HCSA employed. 

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