Three novel poly[3-( p -substituted)benzoyl-2,5-thiophene]s ( Ib, IIb, and IIIb ) were successfully prepared via nickel(0)-catalyzed coupling polymerization of 3-benzoyl-2,5-dichlorothiophene ( Ia ), 3-( p -fluoro)benzoyl-2,5-dichlorothiophene ( IIa ), and 3-( p -toluoyl)-2,5-dichlorothiophene ( IIIa ). To our knowledge, monomers ( IIa ) and ( IIIa ) are new compounds. On the basis of K and α values from the Mark−Houwink relationship, the 〈 M v 〉 of the polymers were in the range 1.50 × 10 5 to 3.51 × 10 5 g/mol. The α value equal to 0.97 is close to unity indicating that the 〈 M v 〉 is approximately equal to the 〈 M w 〉. The high molecular weight polymers were soluble in common organic solvents. Their glass transition temperatures were all above 160 °C and showed no evidence of crystallinity by differential scanning calorimetry. All three polymers were thermally and thermooxidatively stable with 10% weight loss in nitrogen and air occurring above 430 °C. The UV−vis absorption λ max for the three polymers greater than 465 nm is a further evidence of the high molecular weight and the long effective conjugation length.
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Wang et al. (1998) studied this question.