Synthesis and Characterization of Co(II), Ni(II), Cu(II), and Zn(II) Complexes with a New vic-Dioxime (E,E)-N′-Hydroxy-2-(Hydroxyimino)-N-(4-{[(2-Phenyl-1,3-Dioxolan-4yl)Methyl]Amino}Butyl)Ethanimidamide1

Synthesis, characterization, and in vitro anti-neoplastic activity of novel vic-dioximes bearing thiosemicarbazone side groups and their mononuclear complexes

Two novel vicinal dioxime ligands containing thiosemicarbazone units, (2E)-2-[4-(diethylamino)benzylidene]-N-[(1Z,2E)-N-hydroxy-2-(hydroxyimino)ethanimidoyl]hydrazine carbothioamide (L(1)H2) and (2E)-2-[4-(dimethylamino)benzylidene]-N-[(1Z,2E)-N-hydroxy-2-(hydroxyimino)ethanimidoyl]hydrazinecarbothioamide (L(2)H2), were synthesized. Using the HL-60 human leukemia cell line, the in vitro anti-neoplastic activity of these thiosemicarbazone-oxime derivatives was evaluated. Mononuclear nickel(II), copper(II), and cobalt(II) complexes with a metal:ligand ratio of 1:2 for both the L(1)H2 and L(2)H2 ligands were also synthesized. To characterize these compounds, Fourier transform-infrared spectroscopy (FT-IR), mass spectrometry (MS), magnetic susceptibility measurements, (1)H and (13)C nuclear magnetic resonance (NMR), ultraviolet-visible (UV-Vis) absorption spectroscopy, heteronuclear multiple-bond correlation (HMQC), and elemental analysis were performed. For L(1)H2, L(2)H2, and each of their derivatives, antiproliferative effects against HL-60 cells were exhibited and the associated IpC50 values ranged from 5μM to 20μM. Furthermore, L(1)H2 and its derivatives inhibited the proliferation of HL-60 cells more effectively than L(2)H2, and 5μM [Cu(L(1)H)2] exhibited the strongest antiproliferative activity.

Spectroscopic and biological approach of Ni(II), Cu(II) and Co(II) complexes of 4-methoxy/ethoxybenzaldehyde thiosemicarbazone glyoxime

Two novel vicinal dioxime ligands containing (4-methoxybenzaldehyde thiosemicarbazone glyoxime (L(1)H2) or 4-ethoxybenzaldehyde thiosemicarbazone glyoxime (L(2)H2)) thiosemicarbazone units were synthesized and characterized using (1)H NMR, (13)C NMR, HMQC, MS, infrared and, UV-VIS. spectroscopy, elemental analysis, and magnetic susceptibility measurements. Mononuclear nickel(II), copper(II) and cobalt(II) complexes with a metal:ligand ratio of 1:2 for L(1)H2 and L(2)H2 were also synthesized. The effect of pH and solvent on the absorption spectra of both ligands and complexes was determined. IR spectra show that the ligands act in a bidentate manner and coordinates N4 donor groups of the ligands to Ni(II), Cu(II) and Co(II) ions. The detection of H-bonding (O-H⋯O) in the [M(LH)2] metal complexes by IR spectra supported the square-planar MN4 coordination of mononuclear complexes. The antimicrobial activities of compounds L(1)H2, L(2)H2, and their Ni(II), Cu(II) and Co(II) complexes were evaluated using the disc diffusion method against 12 bacteria and 4 yeasts. The minimal inhibitory concentrations (MICs) against 7 bacteria and 3 yeasts were also determined. Among the test compounds attempted, L(1)H2, [Ni(L1H)2], [Cu(L1H)2], L2H2, [Ni(L2H)2] and [Cu(L2H)2] showed some activities against certain Gram-positive bacteria and some of the yeasts tested.

Homo- and heteronuclear complexes of a new, vicinal dioxime ligand

A new symmetrical vicinal dioxime, N,N′-bis-{4-[[(2-hydroxyphenyl)methylene]hydrazinecarbonyl]phenyl}diaminoglyoxime (LH4), was prepared by reacting anti-dichloroglyoxime with salicylaldehyde 4-aminobenzoylhydrazone. The reaction of ligand with Ni2+ salts gave mono-and homopentanuclear complexes, [Ni(LH3)2] and [Ni5(LH)2X2]. Furthermore, heteropentanuclear complexes of dioxime ligand, [Cu4Ni(LH)2X4], were prepared by the reaction of [Ni(LH3)2)] with Cu2+ salt and a monodentate ligand (X = SCN−, CN−, or N3−). The structures of both the new symmetrical vicinal dioxime and its complexes were identified by elemental analyses, IR, 1H NMR, UV-VIS spectra, and magnetic susceptibility. The elemental analyses and spectral data indicate that the hydrazone side of ligand acts as a O,N,O′ tridentate and the fourth position is occupied with monodentate anion such as SCN−, CN−, N3−.