Investigations on optical and structural properties of chiral acids doped conducting polyaniline: An approach towards preeminent helicity induction

摘要

Optically active polyaniline salts have been readily prepared via enantio-selective doping the emeraldine base form of polyaniline in DMF by variety of chiral dopants via suspension method. The induction of helicity is faster by dextro chiral agents than their corresponding laevo enantiomer because of the lesser energy requirement for structural deformation in dextro. CD spectra confirm the incorporation of chiral anion in PANI and helicity induction in visible region. XRD data show that PANI-(+)-HCSA and PANI-Dibenzoyl-D-Tr have orthorhombic symmetry with space group pbcn while the Le-Bail fit of the powder XRD pattern of PANI-(+)-Tr and PANI-(+)- Mnd confirmed triclinic symmetry with space group P−1. The powder X-ray diffraction patterns reveal that PANI is amorphous in nature while chiral acid doped PANI has remarkable crystallinity. SEM micrographs reveal the fibrous morphology of PANI before doping and strong coiling between the fibers of PANI after doping with chiral acids.