Poly(2,5-ethynylenethiophenediylethynylenes), related heteroaromatic analogs, and poly(thieno[3,2-b]thiophenes): synthesis and thermal and electrical properties

Fused Thiophenes and Some Oligomers and Polymers Therefrom

“…Reaction with ethyl 2-sulfanylacetate in the presence of K 2 CO 3 then produced ester 7, saponification of which gave acid 8. Efficient decarboxylation using Cu powder and quinoline at elevated temperature yielded 1 (Scheme 1) [17][18][19][20][21]. 2,6-Diesters 10 were prepared from 9 in high yields using the same ring closure strategy [16].…”

“…An alternative synthesis of 1, also starting from 3-bromothiophene 5, involved transmetallation, introduction of elemental sulfur, then S-alkylation with methyl 2-bromoacetate to give 11. Regioselective Vilsmeier-Haack formylation led regioselectively to 12 and aldol cyclocondensation using NaOMe (or 1,5-diazabicyclo [4.3.0]-non-5-ene (DBN) [22]) afforded the bicyclic ester 13 ready for hydrolysis and decarboxylation (Scheme 2) [18].…”

“…Aldol-type ring closure and a final decarboxylation of 189 give 3-bromothieno[2,3-b]thiophene (187) (Scheme 44) [18].…”

Conjugated Polymers for Organic Solar Cells

“…Chemical structures of thienopyrazine containing polymers P24, P25 and P26 Thieno[3,thiophene is predicted to be kinetically unstable and not isolated yet (Rutherford et al, 1992).…”

A Novel Bipolar Electroluminescent Poly(arylene ethynylene) Consisting of Carbazole and Diethynylthiophene Units

“…[24] Monomer 5 was prepared from 3 and (trimethylsilyl)acetylene in the presence of amine bases and palladium and copper catalysts, and subsequent cleavage of the trimethylsilyl protecting group. [25] PCT was prepared by the palladium-catalyzed Heck-coupling condensation reaction between 2 and 5 in triethylamine and toluene. A mixture of monomer 2 (503 mg, 1.0 mmol) and 5 (132 mg, 1.0 mmol) in triethylamine (20 mL) and toluene (40 mL) was degassed for 30 min.…”