Molar Conductance Magnetic Susceptibility Research Articles

Synthesis, characterization of new 5-(4-nitrophenyl)-4-((4 phenoxybenzylidene)amino)-4H-1,2,4-triazole-3-thiol metal complexes and study of the antibacterial activity

A new Schiff base ligand(HL) was synthesized by condensation of 4-amino-5-(4-nitrophenyl)-4H-1,2,4-triazole-3-thiol with 4-phenoxybenzaldehyde. A new three metal complexes Zn (II), Cd (II) and Hg (II) with Schiff ligand (HL) ware synthesized by molar ratio of ligand : metal as 2:1. The ligand and metal complexes were characterization by H1-NMR, FT-IR, Atomic absorption, CHNS analysis, molar conductivity magnetic susceptibility and melting point. There are study thermal analysis TGA-DTG for the ligand and metal complexes. All complexes were found to be non-electrolyte. The biological activity (antibacterial) in-vitro are investigated for the complexes at prepared concentration (1*10-3 M) and showed inhibition ability against growth of the four types of pathogenic bacteria: [Staphylococcus aurous. and Streptococcus sp.] as gram positive and [Escherichia coli and Pseudomonas aeruginosa] as gram negative. The most of these complexes are effective against both types of bacteria in varying degree, with high activity for Hg (II) complexes.

Geometrical structures, thermal properties and spectroscopic studies of Schiff base complexes: Correlation between ionic radius of metal complexes and DNA binding

A novel series of transition metal complexes of Cu(II), Co(II), Ni(II), Mn(II) and Cd(II) were prepared from Schiff base derived from 4-aminoantipyrine and quinoline-2-carbaldehyde to give 4-((quinolin-2-yl)methyleneamino)-1,2-dihydro-2,3-dimethyl-1-phenylpyrazol-5-one (QMP). The structural features were derived from elemental analysis, mass spectroscopy, X-ray, IR, 1H NMR, electronic spectra, molar conductance magnetic susceptibility and thermogravimetric studies. On the basis of the studies the coordination sites were proven to be through oxygen of the ring CO and nitrogen of the azomethine (HCN) group. The thermodynamic parameters were calculated using Coats–Redfern and Horowitz–Metzger methods. From the values of the thermal activation energy of decomposition (Ea) of Schiff base (QMP) and its metal complexes (1–5), it was found that the Ea value for the complex (3) is higher compared to the other complexes. The Gibbs free energy of decomposition (ΔG⁎) for Schiff base (QMP) and its metal complexes is positive value which indicates that the processes are non-spontaneous. The interaction between Schiff base (QMP) and its metal complexes and calf thymus DNA shows hypochromism effect coupled with obvious bathochromic shift. From the values of binding constant (Kb) we noted that the highest value of Kb is belong complex (3) and these indicated that the Ni(II) is highly binding with CT-DNA and these due to the lower ionic radius. Furthermore, quantum chemical parameters of Schiff base and its complexes were calculated and discussed. The antimicrobial activity of Schiff base (QMP) and its M(II) complexes were studied and compared with the standard antibacterial and antifungal drugs.