LAUSR

Abstract Three new hydrazone ligands, H 2 L 1 , H 2 L 2 and H 4 L 3 , were prepared by condensation of 4,6-bis(1-hydrazonoethyl)benzene-1,3-diol with furan-2-carboxaldehyde, thiophene-2-carboxaldehyde and 1H-pyrrole-2-carboxaldehyde, respectively. The ligands reacted with copper(II), nickel(II), cobalt(II), zinc(II), cadmium(II) and dioxouranium(VI) ions to yield binuclear complexes formulated as [(L)M 2 (OAc) 2 (H 2 O) n (EtOH) m ]·xH 2 O·yEtOH where L = L 1 or L 2 ; M = Cu, Ni, Co, Zn or Cd; n = nil, 1 or 4; m, x and y = nil or 1, [(H 2 L 2 )Cd 2 (OAc) 4 (H 2 O) 2 ]·EtOH, [(L)(UO 2 ) 2 (OAc) 2 (H 2 O) 2 Y 2 ]·nH 2 O where L = L 1 or L 2 ; Y = nil or H 2 O; n = 2.5 or 7, [(L 3 )M 2 (H 2 O) 6 ]·nH 2 O where M = Cu or Zn; n = 1 or 6, [(L 3 )(UO 2 ) 2 (H 2 O) 4 ]·2.5H 2 O and dimeric complexes; [(L 1 ) 2 Ni 2 ]·3H 2 O and [(H 2 L 3 ) 2 M 2 ]·nH 2 O where M = Ni or Co; n = 1.5 or 3. The ligands and their metal complexes were characterized by elemental analyses, IR, 1 H and 13 C NMR, electronic, ESR and mass spectra, conductivity, magnetic susceptibility measurements and powder XRD as well as thermal analysis. The coordinating sites are phenolic oxygens, azomethine nitrogens and the hetero O/N/S atoms. Octahedral, tetrahedral and square planar geometrical arrangements are proposed for metal complexes whilst the uranium ion is hepta- or octa-coordinated. The kinetics of the thermal decomposition for some metal complexes were studied and their thermodynamic parameters were calculated using Coats-Redfern method. The antimicrobial activity of the ligands and their complexes was screened. The antitumor activity of the ligands and their complexes was tested on Ehrlich Ascites Carcinoma. Copper(II) complexes showed promising IC 50 values, which are comparable to that of cisplatin.