Structural studies and biological evaluation of Co (II), Ni (II) and Cu (II) complexes of carbohydrazone derived from ethyl acetoacetate in addition to crystallographic description of La (III) or Sm (III) catalytic activity abnormal product

New carbohydrazone ligand derived from the condensation of carbohydrazide and ethyl acetoacetate, diethyl 3,3 '-(carbonylbis (hydrazin-2-yl-1-ylidene))(3E,3 ' E)-dibutyrate (H4EBC), and its divalent Co, Ni and Cu chelates have been isolated and characterized utilizing convenient methods. H-1-NMR spectrum of H4EBC revealed the abundance of the enol isomer in solution, which was the opposite to what was shown by the solid IR. This was supported by comparing the theoretical IR of both keto and enol forms. In [Ni(H4EBC)Cl-2(H2O)]center dot 2H(2)O, H4EBC acts as a neutral NON tridentate ligand via the (C=O)(carbonyl) oxygen atom besides the two (C=N)(azomethine) nitrogen atoms, while in [Co(H4EBC)Cl-2(2H(2)O)]center dot 2H(2)O, H4EBC behaves as a neutral NN bidentate ligand through the two azomethine groups. Magnetic measurements inherent to their electronic spectra show that both Ni (II) and Co (II) chelates have octahedron coordination frameworks. On the other hand, the ligand behaves as a binegative tetradentate in [Cu-2(H4EBC)Cl-2]center dot H2O via the deprotonated (C=O)(carbonyl) groups of the ethyl acetoacetate framework and the two (C=N)(azomethine) groups. In the latter complex, the carbonyl group of the carbohydrazide moiety is converted to hydroxyl group. Cu (II) complex has a tetrahedral geometry according to ESR and electronic spectral data. The reaction of H4EBC with SmCl3 center dot 6H(2)O or LnCl(3)center dot 7H(2)O gave single crystals of abnormal product (C16H16N4O4). The packing diagram of this crystal has a chain structure. The photoluminescence spectra of [Cu-2(H4EBC)Cl-2]center dot H2O, [Co(H4EBC)Cl-2(H2O)(2)]center dot 2H(2)O and [Ni(H4EBC)Cl-2(H2O)]center dot 2H(2)O display emission broad-bands at 342, 321 and 337 nm, respectively. The microbial behavior of the synthesized moieties was investigated against various bacterial and fungal strains. [Cu-2(H4EBC)Cl-2]center dot H2O complex shows the same activity as ampicillin towards Escherichia coli and Staphylococcus aureus with inhibition zones of 26 and 22 mm, respectively. Antioxidant activity is determined using bleomycin-dependent DNA damage assay besides erythrocyte hemolysis. Finally, in vitro cytotoxic activities against two different cell lines have been examined.