Polyaniline oligomers; synthesis and characterisation

Several poly(p-aniline) leucoemeraldine base oligomers were characterised by 13C NMR spectroscopy. The uncapped trimer and tetramer were obtained by a new method involving a coupling step with copper as a catalyst in DMF. The phenylcapped tetramer, hexamer and octamer were obtained via the “modified Honzl route”. ucoemeraldine base phenylcapped tetramer has been oxidised to its emeraldine base form by silver (I) oxide in THF. The formation of two structural isomers relating to the location of the quinoid ring has been demonstrated by 1H NMR and 13C NMR spectroscopy. The molar ratio of these two isomers has been estimated to 70:30.