Charge-transfer complex formation between p-chloranil and 1,n-dicarbazolylalkanes.

Dimer model compounds of polyvinylcarbazoles (1,n-di(N-carbazolyl)alkanes, when n=1-5) were synthesized to model the effects of distance and orientation between carbazole groups in polymeric systems. Charge-transfer (CT) complexes of carbazole, N-ethylcarbazole and 1,n-di(N-carbazolyl)alkanes with p-chloranil (p-CHL) have been investigated spectrophotometrically in dichloromethane. The colored products are measured spectrophotometrically at different wavelength depending on the electronic transition between donors and acceptor. The formation constants of the CT complexes were determined by the Benesi-Hildebrand equation. The thermodynamic parameters were calculated by Van't Hoff equation. Stochiometries of the complexes formed between donors and acceptor were defined by the Job's method of the continuous variation and found in 1:1 complexation with donor and acceptor at the maximum absorption bands.