Synthesis, X-ray crystallographic studies, DFT calculations and nanostructural features of annulated imidazo[4,5-b]pyridine derivatives

Friedländer-type condensation of 5-amino-4-cyano-1-(phenyl/p-substitutedphenyl)imidazole with cycloalkanone was done by refluxing the mixture with a suspension of anhydrous aluminum chloride in dry 1,2-dichloroethane to produce 7-amino-3-aryl(5,6)cycloalkanoimidazolo[4,5-b]pyridine. Single X-ray crystallographic diffraction studies had shown that compounds had different types of heterodimeric, homodimeric π–π stacking, T-type stacking, and intermolecular hydrogen bonds which lead to nanostructure formation detected by scanning electron microscope. DFT calculation had also been performed to quantify heterodimeric π–π and T-stacking interactions.