Crystal structure, Hirshfeld surface analysis and DFT studies of 6-bromo-3-(12-bromo-dodec-yl)-2-(4-nitro-phen-yl)-4H-imidazo[4,5-b]pyridine.

The title compound, C(24)H(30)Br(2)N(4)O(2), consists of a 2-(4-nitro-phen-yl)-4H-imidazo[4,5-b]pyridine entity with a 12-bromo-dodecyl substituent attached to the pyridine N atom. The middle eight-carbon portion of the side chain is planar to within 0.09†(1)†à and makes a dihedral angle of 21.9†(8)° with the mean plane of the imidazolo-pyridine moiety, giving the mol-ecule a V-shape. In the crystal, the imidazolo-pyridine units are associated through slipped π-π stacking inter-actions together with weak C-H(Pyr)⋯O(Ntr) and C-H(Brmdc-yl)⋯O(Ntr) (Pyr = pyridine, Ntr = nitro and Brmdcyl = bromo-dodec-yl) hydrogen bonds. The 12-bromo-dodecyl chains overlap with each other between the stacks. The terminal -CH(2)Br group of the side chain shows disorder over two resolved sites in a 0.902†(3):0.098†(3) ratio. Hirshfeld surface analysis indicates that the most important contributions for the crystal packing are from H⋯H (48.1%), H⋯Br/Br⋯H (15.0%) and H⋯O/O⋯H (12.8%) inter-actions. The optimized mol-ecular structure, using density functional theory at the B3LYP/ 6-311†G(d,p) level, is compared with the experimentally determined structure in the solid state. The HOMO-LUMO behaviour was elucidated to determine the energy gap.