Gao, Juan published the artcileSynthesis, characterization and photovoltaic properties of conjugated copolymers based on 2-alkyl-thieno[3,4-b]imidazole, Formula: C4Br2N2O4S, the publication is Synthetic Metals (2012), 162(17-18), 1694-1700, database is CAplus.
A new acceptor unit, 2-alkyl-thieno[3,4-b]imidazole, was synthesized through an annulation reaction between a 3,4-diaminothiophene derivative and a carboxyl acid or an acyl chloride, and was used for developing donor-acceptor conjugated copolymers. Copolymerization of 2-alkyl-thieno[3,4-b]imidazole and benzo[1,2-b:3,4-b’]dithiophene (BDT) or dithieno[3,2-b:2′,3′-d]silole (DTS) afforded 6 new low bandgap polymers P1-P6. These polymers possess intensive absorption at 400-650 nm and the optical bandgaps are in the range of 1.69-1.88 eV. They were firstly applied in polymer solar cells and the best efficiency of 0.72% was obtained from P2/PC71BM cells fabricated using a dip-coating method.
Synthetic Metals published new progress about 52431-30-8. 52431-30-8 belongs to bromides-buliding-blocks, auxiliary class Liquid Crystal &OLED Materials, name is 2,5-Dibromo-3,4-dinitrothiophene, and the molecular formula is C4Br2N2O4S, Formula: C4Br2N2O4S.
Referemce:
https://en.wikipedia.org/wiki/Bromide,
bromide – Wiktionary