Novel Polyaromatic Quinone Imines. 2. Synthesis of Model Compounds and Stereoregular Poly(quinone imines) from Disubstituted Anthraquinones

Novel poly(quinone diimines) from anthraquinones symmetrically disubstituted with solubilizing ethyleneoxy or long chain alkoxy groups have been synthesized and characterized. The disubstituted anthraquinones 1,5-bis(2-methoxyethoxy)anthraquinone (EO1AQ), 1,5-bis(2-(2-methoxyethoxy)ethoxy)anthraquinone (EO2AQ), 1,5-bis(2-(2-(2-methoxyethoxy)ethoxy)anthraquinone (EO2AQ), 1,5-bis(2-(2-2-methoxyethoxy)ethoxy)ethoxy)anthraquinone (EO3AQ), 1,5-bis(octyloxy)anthraquinone (15OOAQ), 2,6-bis(octyloxy)anthraquinone (26OOAQ), and 1,4-bis(octyloxy)anthraquinone (14OOAQ) were synthesized and condensed with aniline in the presence of titanium tetrachloride and 1,4-diazabicyclo[2.2.2]octane to give N,N‘-diphenyl-1,5-bis(2-methoxyethoxy) n anthraquinone 9,10-diimine (DEO n AQ, n = 1−3), N,N-diphenyl-1,5-bis(octyloxy)anthraquinone 9,10-diimine (15DOOAQ), and N,N‘-diphenyl-2,6-bis(octyloxy)anthraquinone 9,10-diimine (26DOOAQ), respectively, as model compounds for the polymers. The relative stereochemistry of these diimines was determined by 1H NMR spectroscopy. Polycondensation of the disubstituted anthraquinones with 4,4‘-thiodianiline (SDA) gave high molecular weight (M w 30 000) poly(anthraquinone diimines) and large macrocycles. Polycondensation of 1,4-phenylenediamine (PDA) with EO2AQ gave high molecular weight (M w 14 000) polyaromatic anthraquinone diimines. PDA gave molecular weights of M w 5000−23 000 for the bis(octyloxy)-substituted anthraquinones. The molecular weights of polymerizations incorporating PDA are lowered due to steric interactions of successive repeat units and solubility constraints.