Synthesis, single crystal X-ray analysis and vibrational spectral studies of 3,4-di(1H-indol-3-yl)-1H-pyrrole-2,5‑dione

Indole derivatives are a very important class of heterocyclic compounds that widely exist in natural products and biologically active molecules. In this paper, the title compound 3,4-di(1H-indol-3-yl)-1H-pyrrole-2,5‑dione was designed and synthesized by a three-step reaction of amidation, nucleophilic substitution and cyclization. The title compound was first characterized by four main spectra. Next, the single crystal structure of the title compound was confirmed by X-ray diffraction analysis, and the optimized crystal structure was determined by DFT calculation using the B3LYP/6–311+G(2d, p) basis set. The results show that the molecular structure after DFT optimization is consistent with the crystal structure determined by X-ray single crystal diffraction. In addition, the geometric parameters, MEP, FMO, Hirshfeld analysis, and infrared characteristic vibrational absorption bands of the title compound were also analyzed. Finally, this study also performed antitumor analysis of A549.