Published Paper Details:

A novel bis-oxime Schiff base ligand, Bis(2-hydroxyimino-1-phenylpropylidene)-1,2-diaminobenzene, was synthesized through the condensation of 1,2-diaminobenzene with 2-hydroxyimino-1-phenylpropan-1-one under controlled ethanolic conditions. The ligand was subsequently used to prepare Cu(II), Ni(II), and Co(II) complexes via direct metal-ligand reaction in alcoholic medium. The synthesized complexes were thoroughly characterized using elemental analysis, molar conductance, magnetic susceptibility, FT-IR, UV-Visible spectroscopy, and, wherever applicable, ESR measurements. The spectral data confirmed the successful coordination of the ligand through the oxime nitrogen and phenolic oxygen atoms, supporting a tetradentate N?O? donor mode. FT-IR spectra revealed characteristic shifts in ?(C=N), ?(N-O), and ?(O-H) vibrations upon complexation, while electronic spectra indicated the formation of octahedral structures for the Co(II) and Ni(II) complexes and a distorted square planar or square pyramidal geometry for the Cu(II) analogue. Magnetic moment values were consistent with their assigned geometries and oxidation states. The molar conductivity values suggested the non-electrolytic nature of all complexes. Thermal studies indicated that the complexes exhibit multi-step decomposition patterns, confirming the absence of coordinated or lattice water molecules. The overall analytical, spectral, and thermal results support the formation of stable, well-defined metal complexes with the designed bis-oxime Schiff base ligand. The study provides significant insights into the coordination behavior of oxime-based tetradentate ligands and their ability to stabilize transition metal ions in characteristic geometrical environments. A number of metal complexes of the types M?L, M?L?X? [M = Co(II), Ni(II); X = Cl?, Br?, I?] and Cu?LX? (X = Cl?, Br?), where H?L = bis(2-hydroxyimino-1-phenylpropylidene)-1,2-diaminobenzene have been synthesized and characterized.