Structural Chemistry Of Cu And Ni Complexes Containing N-substituted-salicyl Schiff Base Ligands With ONO Coordination

N-substituted-salicyl Schiff base ligands can act towards transition and non-transition metal ions either as neutral, mono-or dinegative ONO tridentate ligands. N-substituted-salicyl Schiff base ligands and their metal complexes have been the subject of extensive investigations because of their potential pharmacological properties and a wide variation in their modes of bonding and stereochemistry. In this dissertation, the author has carried out the study on the complexes with N-substituted-salicyl Schiff base ligands. Seven title compounds have been synthesized and characterized. The four title complexes containing N-salicylaldehyde-N'-(p-nitrobenzoyl) hydrazone are complexes (Ni₂(C₁₄H₉N₃O₄)₂(C₆H₁₂N₄)(1), [Ni(C₁₄H₉N₃O₄)(C₃H₄N₂)] C₃H₇NO(2), Cu(C₁₄H₉N₃O₄)(C₄H₉NO) (3) and Cu(C₁₄H₉N₃O₄)(C₃H₄N₂)·H₂O (4). The copper or nickel atoms in the complexes 1, 2, 3 and 4 have a square planar (ONO)(N) coordination. In these complexes, one phenolate oxygen, one carbonyl oxygen and one hydrazide nitrogen in the deprotonated N-salicylaldehyde-N'-(p-nitrobenzoyl) hydrazone L^2- are coordinated to metal atom, and one nitrogen atom in coordinated solvent molecule (C₆H₁₂N₄, C₃H₄N₂ or C₄H₉NO) is also coordinated to the metal atom. Two nitrogen atoms from the hexamethylenetetramine are bridged to two nickel atoms in complex 2, forming a binuclear complex. The complex Ni₃(C₁₅H₉O₆N₃)₂(C₅H₅N)₄ (5) exhibits a linear Ni₃ arrangement with Ni(2)…Ni(1) distance of 4.5603(9)A|°and Ni(1)…Ni(2)…Ni(3) angle of 179.05(3) –168.02(3)°. Two pentadentate ligands and two coordinated pyridine molecules are coordinated to the central nickel atom, forming an axially elongated octahedral geometry. However, two nickel atoms on the two sides have square-planar coordination environment. The nickel atom in Ni(C₁₅H₁₁N₃O₅)(C₄H₉NO) (6) has a square planar coordination with (ONO)(N) model. There are two binuclear structure units, two mononuclear structure units and solvent molecules in complex [Fe₂(C₁₄H₉N₂O₂)₃]₂[Fe(C₅H₇O₂)₃]₂.1.5DMF (7). Three bis(salicylidene)hydrazine ligands in the binuclear structure unit [Fe₂(C₁₄H₉N₂O₂)₃] are coordinated to two Fe(III) atoms through their three N-N pairs and six oxygen atoms, obtaining a binuclear complex structure . Some of the title complexes have been characterized by IR spectra, electronic spectra, thermal analyses and EPR spectra.