Synthesis, structural characterization and biological properties of Cu(II), Ni(II), Mn(II), Zn(II) and VO(II) complexes of tetradentate Schiff bases

New binucleating Cu(II), Ni(II), Mn(II), Zn(II) and VO(II) complexes of the prepared ligands with N4 donor were synthesized. The ligands are obtained by the condensation of para-phenylenediamine with diacetylmonoxime and benzilmonoxime. The synthesized ligands and their metal complexes were characterized by elemental analysis and various spectroscopic techniques. The Cu(II), Ni(II) complexes were square planar, VO(II) complex was square pyramidal, whereas Mn(II), Zn(II) complexes were of tedrahedral geometry. Both the ligands and their metal complexes were screened for their antibacterial and antifungal activities by minimum inhibitory concentration method. The results showed that the metal complexes were found to be more active than free ligand. The DNA binding capacities of all the complexes were analyzed by using UV absorption spectra. The DNA cleaving capacities of all complexes were analyzed by agarose gel electrophoresis method against pBR322 DNA

Synthesis, spectral characterization, electrochemical and anti-microbial activities of new binuclear Schiff base metal complexes derived from 3,3’ diaminobenzedine

A novel oxime ligand has been synthesized by refluxing 3,3’-diaminobenzedine and phthalaldehyde monoxime. Copper (II), cobalt (II), nickel (II) and manganese (II) binuclear complexes of this ligand have been prepared and characterized by using elemental analysis, molar conductance studies, IR, UV, NMR, EPR and magnetic studies. The molar conductance measurements correspond to a non-electrolytic nature for all complexes which can be formulated as [M2(L)X4] (Where M = Cu(II), Ni(II), Co(II) and Mn(II); X = Cl−). The UV-visible spectra of all the complexes are well characterized by broad weak d-d band and a high intensity charge-transfer transition. Thermal studies supported the chemical formation of these complexes showed that they decomposed in three or four stages depending on the type of ligand. The far-IR spectrum confirms the presence of coordinate chloride ion in all the complexes as evidenced by one intense far IR bands around 310-330 cm−1. In electrochemical studies the resulting cyclic voltammogram consists of single quasi-reversible one electron transfer. The ligand and complexes have been screened for their antimicrobial activity against two Gram-positive bacteria, two Gram-negative bacteria and fungi. The binuclear metal complexes were found to possess potent antimicrobial, antifungal activity better than ligand alone

Synthesis, characterization, anti-microbial, DNA binding and cleavage studies of Schiff base metal complexes

A novel Schiff base ligand has been prepared by the condensation between butanedione monoxime with 3,3′-diaminobenzidine. The ligand and metal complexes have been characterized by elemental analysis, UV, IR, 1H NMR, conductivity measurements, EPR and magnetic studies. The molar conductance studies of Cu(II), Ni(II), Co(II) and Mn(II) complexes showed non-electrolyte in nature. The ligand acts as dibasic with two N4-tetradentate sites and can coordinate with two metal ions to form binuclear complexes. The spectroscopic data of metal complexes indicated that the metal ions are complexed with azomethine nitrogen and oxyimino nitrogen atoms. The binuclear metal complexes exhibit octahedral arrangements. DNA binding properties of copper(II) metal complex have been investigated by electronic absorption spectroscopy. Results suggest that the copper(II) complex bind to DNA via an intercalation binding mode. The nucleolytic cleavage activities of the ligand and their complexes were assayed on CT-DNA using gel electrophoresis in the presence and absence of H2O2. The ligand showed increased nuclease activity when administered as copper complex and copper(II) complex behave as efficient chemical nucleases with hydrogen peroxide activation. The anti-microbial activities and thermal studies have also been studied. In anti-microbial activity all complexes showed good anti-microbial activity higher than ligand against gram positive, gram negative bacteria and fungi