SYNTHESIS AND STRUCTURE OF HETEROCYCLIC QUINONE ARYLAMINES AS MODEL COMPOUNDS FOR POLYAROMATIC QUINONE IMINES

The structures of model compounds for the polyaromatic quinone diimine polymers were determined. These polymers were obtained by polycondensation of tricyclic quinones with aromatic diamines in the presence of titanium tetrachloride and 1,4-diazabicyclo[2.2.2]octane. The N-phenyldiimine and monoimine derivatives of the following quinones were synthesized: naphthoquinone, 2-methyl- and 2-tert-butyloxazolonaphthoquinone, 2,2'-dimethylbis(oxazolo)benzoquinone, and bisthiophenobenzoquinone. X-ray single-crystal structure determinations are reported for the following derivatives: N,N'-bis(p-fluorophenyl)naphthoquinone 1,4-diimine,N-phenyl-2-tert-butylnaphthol[2,3-d]oxazole-4,9-dione 4-imine and 9-imine, N-(p-fluorophenyl)-2-tert-butylnaphtho[2,3-d]oxazole-9-one 4-imine, N-phenyl-2-isobutylnaphtho[2,3-d]oxazole-9-one 4-imine, and N,N'-diphenylbenzo[1,2-b:4,5-b']dithiophene-4,8-dione diimine. The following common features are observed for these structures: the central ring systems are planar in contrast to the anthraquinone diimine derivatives in which the central ring system is buckled, the N-phenyl ring is twisted out of the plane of the central ring system, and the N-phenyl rings are twisted toward the ring with the heteroatom and away from the C-H group on the adjacent ring. Molecular modeling calculations are found to be in agreement with the X-ray structures. The implications of the crystal structures of the model compounds for the polymeric structures are discussed.