1320201-16-8Relevant articles and documents
Synthesis and characterization of thieno[3,4-b]thiophene-based copolymers bearing 4-substituted phenyl ester pendants: Facile fine-tuning of homo energy levels
Yamamoto, Tomoyuki,Ikai, Tomoyuki,Kuzuba, Mitsuhiro,Kuwabara, Takayuki,Maeda, Katsuhiro,Takahashi, Kohshin,Kanoh, Shigeyoshi
, p. 6659 - 6662 (2011)
A study was conducted to design and synthesize PTB-based polymers bearing 4-substituted phenyl esters in place of the alkyl esters as the pendants of the thieno[3,4-b]thiophene (TT) unit. It was found that their highest occupied molecular orbital (HOMO) energy levels were readily fine-tuned by changing the substituents on the phenyl groups. Four novel TT monomers bearing various phenyl ester groups (TT1-TT4) were easily prepared in one pot from commercially available phenol derivatives and the key precursor compound, 4,6-dibromothieno[3,4-b]thiophene-2-carboxylic acid, which was synthesized by modified literature procedures. The molecular weights of the obtained polymers were determined by size-exclusion chromatography (SEC) in tetrahydrofuran (THF). The thermal stability of these polymers was investigated by thermal gravimetric analysis (TGA) under a nitrogen atmosphere. The results show that all polymers have good thermal stability with 5% weight loss temperatures (Td) above 300 °C, which is adequate for application in PSC devices.