Spectroscopic studies of N-salicyl- N′-2-furanthiocarboxy hydrazine and its 3d metal complexes, new potential antitumour agents

Abstract

A new ONS donor ligand, N-salicyl- N′-2-furanthiocarboxy hydrazine (H 2sfth) has been synthesized, characterized by i.r., 1H, 13C NMR and mass spectral studies and its VO(IV), Mn(II), Fe(II), CO(II), Ni(II) and Zn(II) chelates of the types M(Hsfth) 2 and M(sfth) · nH 2O, a new class of antitumour compounds, have been synthesized and authenticated by analytical data and by molar conductance, magnetic susceptibility and spectroscopic methods. Electronic, photoacoustic and Mössbauer spectra indicate highspin octahedral geometry for all the complexes. Infrared and PMR spectral studies imply mononegative tridentate and dinegative tetradentate behaviour of the ligand in 1 : 2 and 1 : 1 (polymeric) deprotonated complexes, respectively, the bonding sites being thione sulphur, phenolate oxygen and hydrazinic nitrogen in the former type and thiolo sulphur, enolic oxygen and both of the hydrazinic nitrogens in the latter type. The X-band ESR spectral data are further suggestive of two nitrogen coordination with a d XY ground state for vanadium in VO(sfth) · H 2O and octahedral geometry for Mn(Hsfth) 2. The ligand and its Cu(II) complex has been tested for antineoplastic activity, a full account of which together with the synthesis and characterization of the latter is to be published [1].