SYNTHESIS AND CHARACTERIZATION OF NICKEL (II) COMPLEX WITH SCHIFF BASE DRIVE FROM SALICYLALDEHYDE AND ANILINE.

The synthesis and characterization of a nickel (II) complex derived from salicylaldehyde and aniline was successfully carried out to investigate the coordination behavior and structural features of the resulting Schiff base metal complex. The Schiff base ligand was first prepared through a condensation reaction between salicylaldehyde and aniline under reflux, forming an imine compound with characteristic functional groups. The resulting ligand was then complex with nickel (II) chloride to obtain a stable Ni(II) coordination compound. The synthesized complex was characterized using various physicochemical and spectroscopic techniques including melting point determination, solubility tests, Fourier Transform Infrared Spectroscopy (FT-IR). FT-IR analysis confirmed the formation of the imine (C=N) bond and its coordination to the Ni(II) center through observed shifts in key absorption bands, while UV-Visible spectra indicated ligand-to-metal charge transfer transitions typical of square planar or octahedral Ni(II) complexes. The complex exhibited distinct thermal and solubility properties compared to the free ligand, indicating successful metal coordination the C=N (imine) stretching this confirms formation of the Schiff base (C=N azomethine bond), If a metal–oxygen (M–O) or metal–nitrogen (M–N) bond exists, it appears around 600–450 cm ¹ (but the spectrum may not show low enough values clearly), 3350–3100 cm ¹ O–H stretching of phenolic alcohol (salicylaldehyde-derived ligand). Phenolic C–O stretch typically 1300–1200 cm ¹ These confirm phenolic and amine-derived features in the ligand The FTIR spectrum indicates successful formation of a Schiff base ligand derived from salicylaldehyde and a primary amine (likely aniline or ethylenediamine). The strong C=N stretch near 1643 cm ¹ confirms condensation. The phenolic –OH remains present, indicating it did not fully react. A melting-point range of 102–104 °C indicates a good level of purity, although slightly broader than Ligand. Metal complexes often show broader melting ranges due to Coordination geometry. The solubility of Ligand does not significantly increase with heat. as values remain the same (cold vs. hot).