Synthesis, Characterization and Photophysical Properties of Naphtho[2,3-b]Indolizine-6,11-Dione Derivatives.

This communication concerns the synthesis, structural characterization and fluorescent properties of novel naphtho[2,3-b]indolizine-6,11-dione derivatives. The target compound synthesized by one-pot multicomponent reaction between naphthoquinone, indandione and pyridine derivatives.The structures of synthesized compounds were characterized by IR, 1H NMR and 13C NMR analysis. The structure of two compounds was confirmed by single crystal X-ray diffraction. The photophysical properties of synthesized compounds were measured in a variety of organic solvents. The effects of substituents and solvents on UV-vis spectra and fluorescence emission were analyzed. All compounds were showed negative solvatochromism. The fluorescence emission of these derivatives was sensitive to solvent basicity and the large Stokes shifts (up to 129 nm, 4599 (cm-1)) were observed. The similar multicomponent reaction between naphthoquinone, bindone and pyridine derivatives provide the formation of stable non-fluorescent compound possessing zwitter-ionic structure.