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 proc esses, some of which occur relatively slowly even at room temperature in so lution. Possible general approaches for determining the intrinsic propertie s of polyaniline by isolating the polymer preferably in one isomeric form o r as a mixture containing a smaller than usual number of different isomers, are outlined. (C) 1999 Elsevier Science S.A. All rights reserved.