Structure and Biological Activity of Trichlorophenyl-Thiosemicarbazone and its Complexes with Some Transition Metal Cations

Abstract

The complexes of 4-(2,4,6-trichlorophenyl)-3-thiosemicarbazide (HL1) with transition metal cations VO(II), Co(II), Ni(II), Cu(II), Pd(II), and Pt(II) are prepared and characterized using elemental and thermal analyses, UV-visible spectrophotometry, FTIR, mass, and NMR spectroscopy, X-ray diffraction, and molar conductance and magnetic susceptibility measurements. The results show that the prepared chelates have the following chemical formulae and structures: [(VO)2(L1)(SO4)(C2H5O)·H2O] (square based pyramidal structure), [Co2(HL1)Cl3C2H5OH]·Cl (square planar structure), [Ni(HL1)Cl2]·3H2O (square planar structure), [Cu(L1)2(H2O)2] (octahedral structure), [Pd(HL1)Cl2]·H2O (weakly distorted square planar structure), and [Pt(HL1)Cl2]·1/2H2O (square planar structure). Generally, the complexes exhibit a high thermal stability, however, the Pd(II) and Pt(II) complexes are more stable than the other complexes. The ligand (HL1), and its complexes are screened for their biological activity. Some of the complexes are found more biologically active than the parent ligand.