Synthesis and Spectroscopic Studies of Some Metal Complexes Derived from 4-Phenyl-1-Pipridine-3-Thiosemicarbazide (PPTS)

Abstract

The reaction of 4-phenyl-1-pipridine-3-thiosemicarbazide (PPTS) with some hydrated metal salts of Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II), Hg(II) and U(VI)O₂ affords complexes of the types M(HL)Cl.H₂O (M [dbnd] Co(II), Ni(II), Cu(II) or Cd(II)), Cd(HL)₂.3H₂O, M(L).nH₂O (M [dbnd] Mn(II), Zn(II) or U(VI)O₂, n = O-5), Cu^I(HL) and Hg(H₂L)Cl₂ (H₂L = PPTS). Elemental analyses, molar conductivities, magnetic measurements and spectra (IR, visible) have been used to characterize the structure of the isolated solid complexes. The infrared spectra show that the free ligand (PPTS) coordinates either in the keto or enol form and behaves in a bidentate manner but with different modes of bonding. The spectral and magnetic studies suggest a tetrahedral geometry for both Co(II) and Ni(II) and a pseudo-tetrahedral structure for the Cu(II) complex. Also, the ligand acts as a reducing agent giving a diamagnetic complex as in case of Cu^I (HL).