Polymerization of aromatic nuclei. XIX. Polymerization of thiophene by aluminum chloride

Abstract

Abstract Thiophene was polymerized in high yield on exposure to aluminum chloride in solvent under mild conditions. Experimental evidence [IR, NMR, UV, and mass spectra, elemental analyses, reductive desulfurization, and comparison with the literature trimer of thiophene (prepared with phosphoric acid)] suggests the following structure: magnified image From gel permeation chromatography an average weight of 1290 was obtained, which corresponded to the presence of 15 rings; the highest‐molecular‐weight chains contained about 192 rings. Mechanistically, participation of cationic intermediates is proposed. Apparently chain extension can occur by various routes, including participation of neutral oligomer molecules.