Synthesis, spectral, thermal, potentiometric, antitumor, antimicrobial and PM3 studies of pyridazinone hydrazone metal complexes

Abstract

New binary complexes with the general formula [M2(Bpsq)(NO3)n(H2O)4].yEtOH (where n = 0 or 2, y = 0 or ½, M = Cu(II), Ni(II), Co(II), VO(IV), UO2(VI) or Th(IV) ion and Bpsq = 3,4-bis[carboxy-2-hydroxy-benzyledene-5,6-diphenyl-3-(2H)pyridazinone] cyclobut-1-ene-1,2-diol), have been synthesized and characterized by elemental analysis; ESR, mass, UV-Vis and IR spectroscopies, magnetic and conductance measurements, additional to TGA and DSC thermal analysis. The acid-base interactions and their equilibrium constants with transition metal ions were investigated by potentiometric and spectrophotometric techniques in 75% (v/v) dioxane-water solvent at 30 °C. The Bpsq ligand was applied as metal indicator for determination of Cu(II) and VO(IV) by complexometric titrations. The antitumor activity was evaluated in vitro against Hepatocellular carcinoma cell line (HepG-2 cells). The Bpsq ligand exhibited stronger antitumor activity than its Cu(II)- and Ni(II)- complexes. The antimicrobial screening results showed low antimicrobial activity against Bacillus subtilis (bacteria), but moderate against Candida albicats (fungus). The molecular orbital calculations for Bpsq ligand and its complexes were performed using Hyperchem 7.52 program at PM3 level and their data are correlated with the experimental data.