Crystal structure, DFT calculation, Hirshfeld surtace analysis and energy framework study of 6-bromo-2-(4-bromophenyl)imidazo[1,2-a]pyridine

The title imidazo[1,2-a] pyridine derivative, C13H8Br2N2, was synthesized via a single-step reaction method. The title molecule is planar, showing a dihedral angle of 0.62 (17)degrees between the phenyl and the imidazo[1,2-a] pyridine rings. An intramolecular C-H center dot center dot center dot N hydrogen bond with an S(5) ring motif is present. In the crystal, a short H center dot center dot center dot H contact links adjacent molecules into inversion-related dimers. The dimers are linked in turn by weak C-H center dot center dot center dot pi and slipped pi - pi stacking interactions, forming layers parallel to (110). The layers are connected into a three-dimensional network by short Br center dot center dot center dot H contacts. Two-dimensional fingerprint plots and three-dimensional Hirshfeld surface analysis of the intermolecular contacts reveal that the most important contributions for the crystal packing are from H center dot center dot center dot Br/Br center dot center dot center dot H (26.1%), H center dot center dot center dot H (21.7%), H center dot center dot center dot C/C center dot center dot center dot H (21.3%) and C center dot center dot center dot C (6.5%) interactions. Energy framework calculations suggest that the contacts formed between molecules are largely dispersive in nature. Analysis of HOMO-LUMO energies from a DFT calculation reveals the pure pi character of the aromatic rings with the highest electron density on the phenyl ring, and sigma character of the electron density on the Br atoms. The HOMO-LUMO gap was found to be 4.343 eV.