Polyarylanthraquinoneimines: A new family of polymers.

摘要

This work describes a novel technique to prepare a family of polymers which contain a polyquinoneimine backbone. The polymerization utilized a condensation reaction which yielded novel substituted polyanilines. The polymer generating reaction, formation of the imine, was optimized to a quantitative yield via a model compound study. The model quinoneimine was prepared from anthraquinone and two equivalents aniline in the presence of excess of titanium tetrachloride and 1,4-diazabicyclo[2.2.2]octane. The X-ray crystal structure of the model compound from anthraquinone had indicated that the ring system is not planar due to steric hindrance between the peri-hydrogen of anthraquinone and the ortho-hydrogen of the N-phenyl ring. The X-ray crystal structure of the model compound prepared from 4,8-dehydrobenzo-[1,2-b:4,5-b']dithiophene-4,8-dione reveals the quinone moiety to be planar. This indicates that the incorporation of a benzoquinone moiety with two fused thiophene rings in the model compound relieved the steric hindrance observed in the anthraquinone model compound. The model compound synthetic strategy was used to prepare polyquinoneimines from either of the above mentioned quinones and aromatic diamines. The polyquinoneimines were prepared in high yields with molecular weights up to 20,000. The polymers are red powders which are soluble in common organic solvents such as tetrahydrofuran, chloroform and chlorobenzene and form red transparent films. In contrast, polyanilines are typically black insoluble and intractible polymers. Characterization of the polymers prepared from either 4,4'-methylenedianiline or 4,4'-thiodianiline and anthraquinone revealed that 5-20% of the product is a novel low molecular weight macrocyclic quinoneimine.