Novel conjugated polymer containing aromatic ring and selenium in backbone: Addition polymerization of 1,4‐benzenediselenol to 1,4‐diethynylbenzene

Abstract

AbstractA novel addition polymerization of 1,4‐benzenediselenol (BDSe) to 1,4‐diethynylbenzene (DEB) was carried out by UV‐irradiation in toluene at 60°C under nitrogen atmosphere. The polymerization proceeded at such a fast rate as to give 60–70% yield for 6 min. A paleyellowish polymer (M̄n = 20000–30000) precipitated with the progress of the polymerization. In the presence of BPO, the polymerization also proceeded rapidly to give the polymer (M̄n = 18000) in 50% yield for 4 min. The polymer magnified image was insoluble in conventional organic solvents. In the IR spectrum of the polymer, the characteristic absorption bands of cis‐ and trans‐vinylene groups appeared at 1340 and 940 cm−1, respectively. The microstructures of polymers were evaluated as the cis content was 90% and the trans one was 10%, based on the model adducts of benzeneselenol and ethynylbenzene. The cis ← trans isomerization occurred with UV‐irradiation: the cis vinylene group of the polymer decreased from 90 to 40% for 18 h. The electrical conductivity of the polymer was in the order of 10−13 S/cm without dopant, but increased up to 10−5 S/cm on I2 doping. DSC and TG thermograms of the polymer indicated its decomposition point as 465°C under nitrogen atmosphere.