Synthesis and characterization of some homo-and hetero-mono-and trinuclear metal complexes with 4-phenyl-5-(p-aminophenyl)-3-mercapto-1,2,4-triazole

  Taking in account the role the transition metal ion takes place in medicine, especially those of  Ni⁺², Cu⁺², Pt⁺², Pd⁺²,that in addition to those essential for mammalian life , N, S, P and Cl^-, it was decided to prepare a series of new homo-and hetero-polynuclear  complexes including these elements with the substituted triazole ring, to show the possible structural phenomena and biological effect of the ligand. 3-Mercapto-5-(P-aminophenyl )-1,2,4-triazole (ATRZ) have been prepare starting from ethyl benzoate. The reaction of ATRZ with Na₂PdCl₄ in acetone  in 1:1 mole ratio gave the mono-nuclear complex  (Pd (ATRZ) Cl₂)^-1.     The last complex was used to prepare a series of trinuclear homo-and hetero-complexes by reaction of Na₂PdCl₄, K₂PtCl₄, Cu(NO₃)₂ and NiCl₂  in acetone using 1:1 mole ratio , which show to have the general formula

[Cl₂Pd(ATRZ)MCl₂PdCl₂]^-2

where   M= Ni⁺², Pt⁺² and Pd⁺²

The copper complex had the tetranuclear structure of the following formula:

[Cl₂Pd ATRZ Cu₂(̉μ²-NO₃)₂PdCl₂]^-2

    Another set of mono-nuclear mixed ligand complexes of (Pd (ATRZ) Cl₂)^-1 with N, and P-donor neutral ligands ,i.e. monodentate ph₃P, ph₃N, and Et₂NH and chelating 1,10-phenanthroline, have been

show all the prepared by reacting (Pd (ATRZ) Cl₂)^-1 with the appropriate neutral ligand in acetone . The new complexes show to have the general formal                                           [ATRZPdL_n]⁺

where    n=2  for ph₃p, ph₃N, and (Et)₂NH

and        n=1   for  1,10-Phenanthroline

          All the prepared complexes were characterized by their FT-IR and UV-Vis. spectral studies, in addition to magnetic susceptibilily measurements. The metal content was determined by atomic absorption spectroscopy technique. The results metal centers to be diamagnetic with square planar geometry .

     The study of the nature of the complexes formed in acetone solution following the mole ratio(Job) method, gave a results  which were compared successfully with those obtained from solid state studies. The antibacterial and antifungal activity was performed using staphylococcus aureus and E-coli as gram(+) and gram(-) bacteria respectively, while trichophyton rubrum was used as epidermal fungus. The ligand(ATRZ) showed no activity against the studied pathogenic organisms, while, some of its metal complexes showed a promising activity.