Synthesis and Spectral Identification of Novel Na(I), Ca(II), and Fe(III) Complexes Based on 2-Amino Benzothiazole Azo Dye as Analytical Reagent and Study of Their Antimicrobial Efficiency

A pharmacologically significant active scaffold with a wide range of pharmacological activities is the benzothiazole compound and its metal complexes. The present work was designed to synthesize novel Fe(III), Ca(II), and Na(I) complexes using the azo benzothiazole derivative ligand prepared freshly from a diazonium salt solution of 2-amino benzothiazole with p-hydroxybenzaldehyde. The prepared azo ligand and the chelate complexes were categorized through FTIR, UV-vis, 1H-NMR, and mass spectral analysis, and elemental analysis C.H.N.S.O., along with the exploration of their magnetic susceptibility and molar conductivity. According to the collected data by the FTIR spectral chart, the 3-(benzo[d]thiazol-2-yldiazenyl)-4-hydroxybenzaldehyde ligand demonstrates monobasic, bidentate N-N donor behavior. The molar conductivity measurements indicate that the Na(I), Ca(II) chelate complexes are non-electrolytes, while the Fe(III) complex is an electrolyte. The general formula of the synthesized chelate complexes was [MLCl(H2O)], [MLCl2], and [MLCl2]Cl for the Na(I), Ca(II), and Fe(III) complexes, respectively, with the tetrahedral structure for all the complexes. In vitro antibacterial activity experiments were performed to assess the antibacterial efficiency of the free azo ligand and its corresponding complexes; the findings showed that the Fe(III) complex had higher antibacterial efficiency related to the free azo ligand and the Na(I) and Ca(II) complexes.