Chelation, spectroscopic characterization, biological activity and crystal structure of 2,3-butanedione isonicotinylhydrazone: Determination of Zr(4+) after flotation separation

New metal complexes of Co(II), Ni(II) Cu(II), Zn(II), Cd(II), Pd(II) and Hg(II) with 2,3-butanedione isonicotinylhydrazone [BINH] have been prepared and investigated. Single crystal for BINH is grown and solved as orthorhombic with P 21 21 2 space group. The formula of the ligand was assigned based on the elemental analysis, mass spectra and conductivity measurements. The complexes assigned the formulae [M(BINH-H)Cl]⋅nH2O (MCo(II), Ni(II), Cu(II), Zn(II); n=0 or 1); [Hg(BINH-H)(H2O)2Cl]; [Cd(BINH)Cl2]⋅2H2O and [Pd(BINH)Cl2]⋅H2O. All complexes are nonelectrolytes. BINH acts as a tridentate ligand in [M(BINH-H)Cl]⋅nH2O and [Hg(BINH-H)(H2O)2Cl] coordinating through COketonic, COamedic and CNhy and as a neutral bidentate through COketonic and CNhy in [Cd(BINH)Cl2]⋅2H2O and [Pd(BINH)Cl2]⋅H2O; the pyridine nitrogen has no rule in coordination. The data are supported by NMR ((1)H and (13)C) spectra. The magnetic moments and electronic spectra provide a tetrahedral structure for the Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) complexes; square-planar for the Pd(II) complex and octahedral for the Hg(II) complex. The TGA of the complexes depicted the outer and inner water molecules as well as the final residue. The cobalt and cadmium complexes ended with the metal while the Cu(II), Zn(II) and Pd(II) complexes ended with complex species. [Hg(BINH-H)(H2O)2Cl] has no residue. The ligand is inactive against all tested organisms except for Bacillus thuringiensis. The Hg(II) complex is found more active than the other complexes. The flotation technique is found applicable for the separation of micro amount (10ppm) of Zr(4+) using 10ppm of BINH and 1×10(-5)molL(-1) of oleic acid at pH 6 with efficiency of 98% with no interferences.

Synthesis of heterobimetallic complexes: in vitro DNA binding, cleavage and antimicrobial studies

The monometallic (1-3) and heterobimetallic (4-6) complexes, containing 1,10-phenanthroline and indole-3-acetic acid were synthesized and characterized by spectroscopic (IR, UV-vis, NMR, ESI-MS) and analytical methods. The in vitro DNA binding studies of 5 and 6 with CT DNA were carried out by employing various biophysical methods which reveal strong electrostatic binding via phosphate backbone of DNA helix. The binding constant (K) value as determined from fluorescence experiments of complexes 5 and 6 were calculated to be 4.09×10(4) and 2.51×10(4) M(-1), respectively revealing that complex 5 has greater binding propensity for DNA. To gain further insight into the molecular recognition at the target site, interaction studies of 5 with 5'-GMP were carried out by employing (1)H and (31)P NMR spectroscopy. Complex 5 exhibited preferential selectively towards the minor groove of pBR322 DNA and efficient cleavage activity via hydrolytic pathway. Furthermore complexes 4-6 exhibited significant antimicrobial activity.