STRUCTURE OF SOLUBLE POLY(3-ALKYLTHIOPHENE)S

H-1 NMR spectra of poly(3-dodecylthiophene) and poly(3-dodecylthiophene-co-3-methylthiophene)s show two chemical shifts for the alpha-(1)- and beta-(2)-methylene protons of the monomeric units of 3-dodecylthiophene as well as for the methyl protons of the monomeric units of 3-methylthiophene. This fact would explained by the presence of head-to-head and head-to-tail configurations in dyad sequences. The spectra of poly(3-dodecylthiophene) show that the resonances of 4-protons on the successive 2,5-linked thiophene ring are resolved into four peaks due to different triad sequences. A pair of doublet peaks at delta = 6.93 and 7.16 are assigned to the 4- and 5-protons on the terminal 2-substituted thiophene rings and peaks due to the other terminal units were not detected. The intensity of the doublet peaks suggests that the degree of polymerization of PDDT is about 170.