INFLUENCE OF THE CHIRAL DOPANT ANION ON THE GENERATION OF INDUCED OPTICAL-ACTIVITY IN POLYANILINES

Emeraldine base (EB) is doped with (1S)-(+)-3-bromocamphor-10-sulfonic acid and a novel chiral acrylamidesulfonic acid (4) in NMP and DMF so lvents to give new optically active polyaniline salts (PAn.HA). The co njugate base anions (A(-)) of these chiral dopants (as with the previo usly studied (+)-camphor-10-sulfonic acid, HCSA) contain SO3- and carb onyl (C=O) groups that may maintain the polyaniline chains in a prefer red one-sense helical screw via simultaneous electrostatic and H-bondi ng. Optically active polyaniline salts are also produced via analogous doping of EB (in NMP or DMF) with the chiral dicarboxylic acids (+)- or (-)-tartaric acid and O,O'-dibenzoyl-D-tartaric acid, which possess quite different structural motifs to HCSA. A common feature of all th e dopants successful in generating optically active polyaniline salts is their bidental nature, allowing attachment of the dopant to the pol ymer backbone at two places simultaneously. (C) 1997 Elsevier Science Ltd.