Synthesis, Characterization and Bio-Potential Activities of Co(II) and Ni(II) Complexes with O and N Donor Mixed Ligands

The synthesis and characterization of Co(II) and Ni(II) mixed ligand complexes are derived from isoniazid, 9-fluorenoneandoxalate. The metal complexes were characterized on the basis of elemental analysis, IR, UV-visible, CV, PXRD, and molar conductance analytical data, viz., all the metal complexes were suggested in an octahedral geometry, respectively. The mixed ligand complexes are formed in the 1:1:2:1 (M:L1:L2:L3) ratios, as found from the elemental analyses, and originate to have the formula [M(L1)(L2)2(L3)]. Where M = Co(II), Ni(II), L1 = isoniazid, L2 = 9-fluorenone, and L3 = oxalate. The molar conductance data reveals that the complexes are non-electrolytes. The cyclic voltammogram of the Co(II) complex revealed that the quasi-reversible single electron transfer process and Ni(II) complex corresponding to a one-electron transfer process were observed during controlled potential electrolysis. IR spectra show that the ligands are coordinated to the metal ions through N and O donor sites of isoniazid-N, 9-fluorenone-O and oxalate-O. Magnetic moment values and UV-visible spectra were used to infer the coordinating of the geometrics of these complexes found to be octahedral. The PXRD patterns suggest that all the complexes are crystalline phases. The metal chelates have been screened for antimicrobial, antioxidant and anti-inflammatory activities, and our findings have been reported, explained and compared with some known antibiotics.

Automated summary

This study synthesized and characterized Co(II) and Ni(II) mixed ligand complexes derived from isoniazid, 9-fluorenone, and oxalate. Various analytical techniques were used to determine the properties of the metal complexes, revealing an octahedral geometry. The ratios of the mixed ligands in the complexes were found to be 1:1:2:1 (M:L1:L2:L3), and the formula for the complexes was [M(L1)(L2)2(L3)]. The complexes exhibited non-electrolyte behavior according to molar conductance data, and the cyclic voltammogram showed quasi-reversible single electron transfer for the Co(II) complex and one-electron transfer for the Ni(II) complex. The infrared spectra indicated coordination of the ligands through N and O donor sites. Magnetic moment values and UV-visible spectra supported the octahedral geometry of the complexes. X-ray diffraction patterns confirmed the crystalline nature of the complexes. The antimicrobial, antioxidant, and anti-inflammatory activities of the metal chelates were evaluated and compared with known antibiotics.