Indolyl imine substituted BODIPY systems; synthesis, photophysical, and biological properties

Abstract

In the study, 4,6-dimethoxy-2,3-diphenylindole-7-carbaldheyde 2, served as a valuable precursor for the reaction with both aniline and BODIPY-linked aniline, generated novel indolyl-imine Schiff base ligands 3 and 7. These indolyl-imine ligand systems were then employed to create the corresponding N-N six -membered boron complexes, 4 (precursor) and 8. The structure of novel compounds were confirmed by 1H and 13C NMR, and high-resolution mass spectrometry. The final evidences of indolyl-imine 7 and its corresponding boron complex 8 were further supported by the single X-ray crystal structures. Single crystal X-ray diffraction analysis revealed the formation of short C-H center dot center dot center dot F, C-H center dot center dot center dot p, C-H center dot center dot center dot O and C-H center dot center dot center dot B interactions, which led to the impressive supramolecular tubular-like (7) and helical (8) self -assemblies. The investigations of the UV-Vis absorption and fluorescence emission properties of the targeted compounds 4, 7 and 8 were carried out using absorption and fluorescence emission (2D and 3D) spectroscopic techniques. Fluorescence properties of the targeted compounds were found to be solvent -dependent. DFT optimized structures and the TD-DFT calculations were in alignment with the experi-mental studies. Additionally, the cytotoxic properties of the target compounds were examined in human breast cancer cells, MCF-7 in vitro as preliminary biological study.(c) 2023 Elsevier Ltd. All rights reserved.