Spectroscopic, thermogravimetric and antibacterial studies for some bivalent metal complexes of oxalyl-, malonyl- and succinyl-bis(4-p-chlorophenylthiosemicarbazide)

Abstract

Abstract Anodic oxidation of Co, Cu, Zn, and Sn metals in an anhydrous acetone solution of 1,1-oxalyl-, malonyl- or succinyl-bis(4- p -chlorophenylthiosemicarbazide) yields a new polynuclear complexes. The isolated complexes have the general composition [M 2 (L)(H 2 O) 6 ], L = pClSuTS and M = Co(II), Cu(II) or Sn(II), [M 2 (L)(H 2 O) n ]· n H 2 O where M = Cu(II), Co(II) or Sn(II), L = pClOxTS and n = 2 or 6, and [M 2 (L)(ac) 2 ]· n H 2 O where M = Co(II) or Zn(II), L = pClOxTS or pClSuTS and n = 2. The thermogravimetry (TG) and derivative thermogravimetry (DTG) have been used to study the thermal decomposition of the investigated bisthiosemicarbazide ligands and their metal complexes. The kinetic thermodynamic parameters such as: E ∗ , Δ H ∗ , Δ S ∗ and Δ G ∗ are calculated using Horowitz–Metzger (HM) and Coats–Redfern (CR) equations. The kinetic thermodynamic parameters such as: E ∗ , Δ H ∗ , Δ S ∗ and Δ G ∗ are calculated from the DTG curves. The tested compounds show a reasonable activity against four strains of Gram-negative bacteria; Escherichia coli , Pseudomonas aeruginosa species and Gram-positive bacteria ; Bacillus cereus and Staphylococcus aureus .