Facile synthesis of bis(indol-3-yl)methane derivatives catalyzed by carboxylic acid functionalized ionic liquid at room temperature: Investigation of photophysical properties, DFT calculations and molecular docking with bovine serum albumin

Herein, we present an improved protocol for the synthesis of bis(indolyl)methanes using 6 mol% [BCMIM][Cl] ionic liquid via facile, one-pot, metal-free synthesis in aqueous ethanol at ambient temperature. In 15–55 min, a series of 48 derivatives were obtained in up to 94 % yields and were characterized using several spectroscopic techniques. UV–visible and fluorescence spectroscopies were used to investigate the photophysical behaviour of the synthesized bis-indole derivatives. The absorption and emission spectra exhibit the wavelength λmax at 298–379 nm and 327–352 nm, respectively. Theoretical calculations show a similar trend to the experimental investigations. The synthesized derivatives were assessed for their binding affinities with Bovine Serum Albumin (BSA) using AutoDock Vina. The results revealed a spectrum of affinities ranging from −7.9 to −10.5 kcal mol−1.