Oligomers and isomers: new horizons in poly-anilines

The extraordinarily important potential role of isomers in determining the electronic, magnetic, optical, structural and mechanical properties of poly-anilines, including polyaniline is presented. It is based on a summary of known types of isomers—positional, cis/trans, rotational—and isomerism processes, some of which occur relatively slowly even at room temperature in solution. Possible general approaches for determining the intrinsic properties of polyaniline by isolating the polymer preferably in one isomeric form or as a mixture containing a smaller than usual number of different isomers, are outlined.