ELECTROCHEMICAL AND SPECTROSCOPIC PROPERTIES OF INDOLIZINO[1,2-B] QUINOLE DERIVATES

A series of indolizino[1,2-b] quinole derivates compounds were characterized by various electrochemical and spectroscopic techniques. Electrochemical studies reveal that there are two redox processes controlled by diffusion, the first step corresponds to the formation of a semiquinone radical Q--, while the second step corresponds to the formation of quinone dianion, Q2--. The presence of acceptor groups such as -CN and -COOH shifted reduction potentials, due to a more favorable electronic stabilization. There was no significant effect of the substituents on the absorption spectra of indolizino[1,2-b] quinole derivates. The substituents influenced the fluorescence properties from indolizino[1,2-b] quinole derivates. The emission and excitation spectra obtained of these compounds suggested that the molecule emits from a locally excited state having identical geometry with that of ground state geometry. Finally it was observed that the group with higher acceptor capacity (-CN), has the highest quantum yield, which is indicating that this group always stabilized electronic state with a higher conjugation.