Water-process able chiral polyaniline derivatives doped and intertwined with dextran sulfate: Synthesis and chiroptical properties

Water-processable molecular complexes between dextran sulfate (DSA) and polyaniline derivatives (PANIs) have been synthesized by chemical polymerization of corresponding achiral monomer in the presence of DSA. The formation of the macromolecular complex was proved by the FTIR and UV-vis spectra. Interestingly, chiral macromolecular architecture was induced into PANIs due to the induction of DSA as macromolecular dopant in the formation of intermacromolecular complex, which was confirmed by the CD spectra. Furthermore, it was found that the substituents in aniline ring have a great effect on the chirality of final PANIs. Through the studies on ionic strength effect, dedoping and redoping, and thermochromism, it was established that the electrostatic interaction not only drove the interpolymer complexation but also played an important role in holding the chiral architecture of PANIs in the resultant macromolecular complexes. The study has also been performed toward the electrochemical activity, chirality in various redox states, and conductivity of PANI-DSA. The design and synthesis of such macromolecular complexes provides another example that the chiral macromolecular architecture of a synthetic macromolecule could be controlled at the molecular level by intermacromolecular complex formation, which often occurs in biopolymers.