Murad, Ary R. published the artcileInfluence of fluorine substitution on the optical, thermal, electrochemical and structural properties of carbazole-benzothiadiazole dicarboxylic imide alternate copolymers, Name: 2,5-Dibromo-3,4-dinitrothiophene, the publication is Polymers (Basel, Switzerland) (2020), 12(12), 2910, database is CAplus and MEDLINE.
In this work four novel donor-acceptor copolymers, PCDTBTDI-DMO, PCDTBTDI-8, P2F-CDTBTDI-DMO and P2F-CDTBTDI-8, were designed and synthesized via Suzuki polymerization The first two copolymers consist of 2,7-carbazole flanked by thienyl moieties as the electron donor unit and benzothiadiazole dicarboxylic imide (BTDI) as electron acceptor units. In the structures of P2F-CDTBTDI-DMO and P2F-CDTBTDI-8 copolymers, two fluorine atoms were incorporated at 3,6-positions of 2,7-carbazole to investigate the impact of fluorine upon the optoelectronic, structural and thermal properties of the resulting polymers. P2F-CDTBTDI-8 possesses the highest number average mol. weight (Mn = 24,200 g mol-1) among all the polymers synthesized. PCDTBTDI-DMO and PCDTBTDI-8 show identical optical band gaps of 1.76 eV. However, the optical band gaps of fluorinated copolymers are slightly higher than non-fluorinated counterparts. All polymers have deep-lying HOMO (HOMO) levels. Changing the alkyl chain substituents on BTDI moieties from linear n-octyl to branched 3,7-dimethyloctyl groups as well as substituting the two hydrogen atoms at 3,6-positions of carbazole unit by fluorine atoms has negligible impact on the HOMO levels of the polymers. Similarly, the LUMO (LUMO) energy levels are almost comparable for all polymers. Thermogravimetric anal. (TGA) has shown that all polymers have good thermal stability and also confirmed that the fluorinated copolymers have higher thermal stability relative to those non-fluorinated analogs. Powder X-ray diffraction (XRD) studies proved that all polymers have an amorphous nature in the solid state.
Polymers (Basel, Switzerland) 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, Name: 2,5-Dibromo-3,4-dinitrothiophene.
Referemce:
https://en.wikipedia.org/wiki/Bromide,
bromide – Wiktionary