Spectral Properties and Biological Activities of Binuclear Mixed-Metal Bridged Thiocyanate Complexes Containing Schiff Bases Derived from Isatin

This study introduces two novel Schiff base ligands synthesized through the condensation of isatin with primary amines. These ligands were characterized using infrared (IR), ultraviolet-visible (UV-Vis) spectroscopy, mass spectrometry, and elemental analysis. The ligands were further treated with tetrathiocyanate in a 1:1 molar ratio to yield binuclear mixed-metal monomeric bridged complexes of the form LMCd(SCN)4, where M represents Co(II) or Ni(II). Various spectral techniques and magnetic susceptibility measurements were employed for the identification of these complexes. The findings revealed that all the complexes possessed a coordination number of four and exhibited non-electrolytic behavior. Additionally, the cobalt complexes demonstrated paramagnetic properties, whereas the nickel complexes were diamagnetic. The antimicrobial efficacy of the Schiff base ligands and their complexes was also evaluated against selected microorganisms, revealing significant antimicrobial activities.