Novel 6-(1H-benzo[d]imidazol-2-yl) benzo[a]phenazin-5-ol Derivatives with Dual Emission and Large Stokes Shift Synthesis, Photophysical Properties and Computational Studies

Abstract

Novel phenazine containing dyes were obtained by the condensation of 5-hydroxybenzo[a]phenazine-6-carbaldehyde and 5-chloro-benzo[a]phenazine-6-carbaldehyde with 1,2-diaminobenzene. The dyes were characterized by FT-IR, 1H NMR, elemental analysis and mass spectra. The UV-vis absorption and fluorescence emission spectra of the dyes were studied in solvents of differing polarity; the dyes exhibited excited state intra molecular proton transfer. The structural changes due to excited state intramolecular proton transfer (ESIPT) phenomenon in terms of bond angle, bond distances and geometry were investigated with the help of DFT computations. The computed absorption and emission were in agreement with the experimental absorption and emission.

Photochemical and electrochemical regioselective cross-dehydrogenative C(sp2)–H sulfenylation and selenylation of substituted benzo[a]phenazin-5-ols

“…Upon scrutinizing the structural skeleton, yellowish-orange color, and literature reports on the photophysical properties of phenazine-related compounds, 19 we anticipated that benzo[ a ]phenazin-5-ol substrates might act as self-photosensitizers in implementing the chemical transformation. To get an idea about this, we first studied the UV-vis light absorption behavior of the model substrate, benzo[ a ]phenazin-5-ol ( 1a ), in DMSO solution (light yellowish-brown, Fig.…”

A review on lawsone-based benzo[a]phenazin-5-ol: synthetic approaches and reactions

“…Also, the UV-vis absorption and fluorescence emission spectra of these compounds were studied in solvents of differing polarity; the dyes exhibited excited state intramolecular proton transfer. 103 …”