Pharmacological and quantum chemical studies of 2-aminobenzo[d]thiazol-3-ium 4-chlorobenzenesulphonate: Synthesis, spectral, thermal analysis and structural elucidation

The organic charge transfer complex 2-aminobenzo[d]thiazol-3-ium 4-chlorobenzenesulphonate (2ABT4CBS) was synthesized and grown as single crystals by slow solvent evaporation method at room temperature. Single crystal X-ray diffraction results revels that 2ABT4CBS crystallized into a monoclinic crystal system with space group P21/c. The molecular structure and functional groups were analyzed by spectral studies such as 1H and 13C NMR, UV–Visible and FT-IR. Thermal stability of the compound was determined by TG and DTAanalysis. DFT was used in the calculation of the frontier molecular orbital (FMO), Mulliken load distribution and thermodynamic properties by employing B3LYP/6-31G (d,p) and HF/6-31G levels of theory. The results of the DNA binding demonstrate that the synthesized compound 2ABT4CBS interacts with CT-DNA in a considerable way. The antioxidant capabilities of 2ABT4CBS were also analyzed against DPPH radical and excellent radical scavenging abilities were identified. Molecular docking studies with PDB: 1BNA, clearly suggested that synthesized compound show binding affinity to the minor groove and established hydrogen bonding with DA5 of CT-DNA.