Investigation of spectroscopic properties of mono and Di-styryl indole-containing BODIPYs

Abstract

In the current study, two novel mono- and distyryl BODIPYs have been successfully synthesized employing the Knoevenagel type condensation reaction between 1,3,5,7‑tetramethyl BODIPY and 2,3-diphenyl-4,6-dimethoxyindole-7-carbaldehyde. This CC bond extension approach leads to change in hybridization of methyl carbon from sp3 to sp2 which play quite important role in the photophysical properties of BODIPYs by allowing extended conjugation. The absorption and fluorescence spectroscopy were used to determine the photophysical properties include molar extinction coefficient, fluorescence lifetime and fluorescence quantum yield. Moreover, the effect of solvent polarity on targeted BODIPY units were analysed with experimental investigations. The Density Functional Theory (DFT)-optimized structures were consisted with the experimental data obtained from the single-crystal X-ray structures.