Synthesis, Characterization, and Photophysical Probing Interaction Studies on Azo‐Sulfonamides Acting as Potent Anti‐Tubercular Agents

Abstract By utilizing the sulfamethizole component via the diazo‐coupling approach by electrophilic substitution process, an unprecedented series of four mono‐azo sulfonamide molecules were synthesized in good yield. Spectroscopic investigation unambiguously confirmed the structures of the newly synthesized mono‐azo sulfonamide derivatives, including FT‐IR, NMR ( 1 H and 13 C), HRMS, Uv‐Vis, and Photoluminescence (PL). In a variety of organic solvents, the 3‐diethylaminophenol coupled azo‐sulfonamide T 3 showed a maximum bathochromic shift of λ max in the range 462–479 nm and in the region of 88–142 nm, a derivative of 2‐hydroxy‐1,4‐naphthoquinone T 4 coupled azo colourant showed a significant Stokes shift. Conceptual density function theory was also used to build a new family of high energy density energetic mono‐azo sulfonamides. Frontier molecular orbitals (HOMO‐LUMO) and global reactivity descriptors were identified to analyze how molecules interact with one another. Further, the potency of the anti‐tubercular activity of the colorants was examined with the standards such as Isoniazid, Ethambutol, Pyrazinamide, Rifampicin , and Streptomycin . The results indicated that‐ Lawsone pigment (2‐hydroxy‐1,4‐naphthoquinone) incorporated azo molecule T 4 displayed the sensitivity at 3.12 μg/mL compared with other the three mono‐azo molecules.