o,p-polyaniline:: A new form of a classic conducting polymer

A new o-PANI-co-p-PANI copolymer was prepared in order to allow for the introduction of solubilizing and function-enhancing substituents on the conducting polymer backbone without concomitant loss of conductivity. An urea-protected trimeric aniline macromonomer with para-ortho-para connectivity and bromine end groups was condensed using palladium catalysis with a di-BOC-protected trimeric aniline comonomer with all para connectivity and amine end groups to give 5p,o-PANI. The new polymer has a repeat unit consisting of five para-substituted aniline rings for every one ortho-substituted aniline ring. The regioregularity of 5p,o-PANI {M-n = 14 000, GPC in NMP, polystyrene standards) was established using H-1 NMR, C-13{H} NMR, and IR spectroscopy. Analogous with p-PANI, the 5p,o-PANI exhibited three distinct oxidation states. The conductivity of blends of 5p,o-PANI and PVC was on the same order of magnitude as the conductivity of PANI films prepared under the same conditions.