Conjugated polymer synthesis from 2,5-dichloro-3,4-dinitrothiophene

Abstract

New conjugated polymers were synthesized via nucleophilic aromatic substitution (SNAr) polymerizations. 2,5-dichloro-3,4-dinitrothiophene (DCDNT) as a main acceptor monomer was polymerized together with varieties of nucleophilic monomers as donor units. For some of the monomers: DCDNT was synthesized in 78% yield, and 1-n-octyl-1H-pyrrole (1), N1,N4-dioctylbenzene-1,4-diamine (2) and 2-heptylbenzimidazole (4) were also synthesized in 75%, 54% and 33% yields, respectively. The reactions of DCDNT with compound 1, n-butylamine, and compound 4 were unsuccessful, in which the reactions with compound 1 and n-butylamine did not give any polymeric products. However, the reactions with 3,4-ethylenedioxythiophene (EDOT), 3,4-dimethoxythiophene (DMT), sodium sulfide, hydrazine, p-phenylenediamine, N,N’-di-sec-butyl-p-phenylenediamine and compound 2 yielded polymers 7, 8, 9, 12, 13, 15 and 17, respectively. The polymers were insoluble in common organic solvents. They exhibited the characteristic absorptions in the visible region of conjugated polymers with a maximum wavelength absorption (λmax) in the range of 540-690 nm.