Synthesis, Spectral and Theoretical Studies of Macrocyclic Cu(II), Ni(II) and Co(II) Complexes by Template Reaction of Malonic Acid with Metal (II) Chloride and Urea or Thiourea

Six new macrocyclic complexes were synthesized by template reaction of urea or thiourea with malonic acid and metal (II) chloride. The metal to ligand ratio of the complexes was found to be (1:1). The Co(II) and the Ni(II) complexes are proposed to be square planar and Cu(II) complexes are proposed to be octahedral geometry. Macrocyclic complexes are (1:2) electrolytes for Cu(II) and Ni(II) complexes while Co(II) complexes are non-electrolytic nature as shown by their molar conductivities (ΛM) in DMSO (Dimethyl sulphoxide) of 10-3 M solution. The structure of metal complexes from FTIR, UV-Vis., magnetic susceptibility measurements, molar conductivity measurements, atomic absorption and melting points. A theoretical treatment of the formation of complexes in the gas phase was studied, this was done using the HYPERCHEM-6 program for the Molecular mechanics and Semi-empirical calculations.
The complexes have been tested for their antibacterial activities against Two types of human pathogenic bacteria (Staphylococcus aureus and Escherichia coli). The first are Gram positive while the second are Gram negative (by using agar well diffusion method). Finally, it was found that compounds show different activity of inhibition on growth of the bacteria.