Novel organic–inorganic hybrid dimethyltin(IV) complexes of heterocyclic carboxylic acid and N-phthaloyl amino acids: Design, synthesis, spectroscopic characterization, DFT calculations and their anti-oxidant potential

Four new organic–inorganic hybrid dimethyltin(IV) complexes (1–4) having general formula Me₂SnAL which were generated by the reaction of dimethyltin(IV) dichloride with sodium salts of indole-3-acetic acid (AH) and flexible N-phthaloyl amino acids (LH) in 1:1:1 molar ratio in refluxing dry THF. The plausible structure of newly generated complexes has been elucidated on the basis of spectroscopic [IR, NMR (¹H,¹³C,¹¹⁹Sn), HRMS] studies. The suggested five coordinated geometry of the hybrid dimethyltin(IV) complexes have been further supported by computational calculations using density functional theory (DFT). DFT calculations were carried out using B3LYP/6-31G* functional basis set. DFT calculations furnish an insight into the optimized geometry, optimized energy, stability, global reactivity descriptors and frontier molecular orbital (FMO) analysis of newly synthesized organic–inorganic hybrid dimethyltin(IV) complexes. These newly synthesized complexes were also evaluated for their anti-radical activity by DPPH free radical scavenging assay. All the dimethyltin(IV) complexes acted as efficient radical scavengers.