Nevin Karaböcek

Mono- and dinuclear copper(II) complexes of a Schiff base ligand, 4′,5′- bis(salicylideneimino)benzo-15-crown-5

Abstract Mono- and dinuclear copper(II) complexes with a tetradentate Schiff base, 4′,5′-bis(salicylideneimino)benzo-15-crown-5, (SALH2) have been prepared and characterized by elemental analyses, magnetic moments, IR, UV/VIS, and ESR spectral studies. The elemental analyses, stoichiometry and the spectroscopic data of the complexes indicate that the copper(II) ions are coordinated by the dianion of the ligand. IR spectra show that the ligand acts in a tetradentate manner and coordinates throught (CN) and (CO) groups. The geometry of the metal chelates is discussed with the help of magnetic and spectroscopic measurements.

Models for copper-proteins: Structure and properties of dimeric copper(I) and (II) complexes of a tetraamino-tetrathioether ligand☆

Abstract Reaction of the binucleating ligand 6,6′-bis(5′-amino-3, ′4′-benzo-2′-thiapentyl)-1,11-diamino-2, 3:9, 10-dibenzo-4,8-dithiaundecane (H 4 L) with copper(II) salts in dried methanol (MeOH) results in the isolation of the mixtures of copper(I) and (II) complexes with Cl − and ClO 4 − counterions. The major products were the copper(I) complexes obtained pure after recrystallization from DMSO-MeOH. The ligands lose four protons from the amine functions to form copper(I) complexes of the general formula (Cu 2 L)X 2 , where X = Cl − , ClO 4 − . The complexes were oxidized to (Cu 4 L)X 4 with hydrogen peroxide in DMF. Cu(NO 3 ) 2 , on the other hand, gave [Cu 2 (H 4 L)(NO 4 ) 2 ](NO 3 ) 2 . The structure consists of two copper(I) and copper(II) atoms, each of which is coordinated through two thioether and two primary amine atoms. The two copper sites are linked through a saturated spiro carbon atom. The copper complexes were characterized by elemental analyses, molar conductivities, magnetic moments, and spectra (UV-Vis, IR).

Copper(II)–nickel(II) complexes of novel 1,9-dioxa-3,6-dithiacyclotridecane-10,12-dione and 1,4-dioxa-7,10-dithiacyclododecane-2,3-dione ligands

Abstract1,9-Dioxa-3,6-dithiacyclotridecane-10,12-dione (L1), and 1,4-dioxa-7,10-dithiacyclododecane-2,3-dione, (L2), two novel ligands, and their mono- and di-nuclear copper(II) and/or nickel(II) complexes have been prepared and characterized by elemental analyses, 1H- and 13C-n.m.r., i.r., magnetic moments and mass spectral studies. Elemental analyses, stochiometric and spectroscopic data on the complexes indicate that the metal ions are coordinated to the nitrogen, oxygen and sulphur atoms and the data support the proposed structure for the diones and their mono–dinuclear copper(II) complexes. Moreover, copper(II) complexes of the dione ligands have a 1:1 metal:ligand ratio.

THE SYNTHESIS AND CHARACTERIZATION OF COPPER(II) COMPLEXES OF A NOVEL BINUCLEATING TETRAOXIME LIGAND

Abstract 6,6′-Methylenebis-[1,11-di(hydroximino)2,3:9,10-dibenzo-4,8-dioxaundecane], (H 4 L) 4 was prepared by the reaction of 6,6′-methylenebis-(5′-on-3′,4′-benzo-2′-oxapentyl)-1,11-dion-2,3:9,10-dibenzo-4,8-dioxaundecane, 3 with hydroxylamine hydrochloride. Di- and tetranuclear copper(I) and (II) complexes with a bistetradentate ligand, (LH 4 ) have been prepared and identified by a combination of elemental analysis, 13 C, 1 H-NMR, mass spectra, magnetic moments, IR, UV/Vis, and ESR spectral studies. A geometric optimization of the synthesized ligand 4 was made by the method of molecular mechanics (MM2) in order to establish a stable conformation. The total energy for these conformations are calculated to be 10.94 and 9.49 kcal/mol.

Synthesis and Structural Studies of 2,2′-[(2E,5E)-hexane-2,5-diylidenedi-nitrilo]-dibenzenethiol and 2-Hydroxybenzaldehyde (2E,5E)-hexane-2,5-diylidenehydrazone ligands and their Mononuclear Cu(II) and Ni(II) Complexes

Monomeric copper(II) and nickel(II) complexes with tetradentate two new ligands, 2,2′-[(2E,5E)-hexane-2,5-diylidenedi- nitrilo]dibenzenethiol(H2L) and 2-hydroxybenzaldehyde (2E,5E)-hexane-2,5-diylidenehydrazone(H2L1) have been synthesized and characterized by elemental analyses, magnetic moments, molar conductance, 1H-NMR and 13C-NMR, IR, mass spectral studies, theoretical calculations (MM2 and AM1) molecular methods. The mononuclear metal complexes of H2L and (H2L1) were found to have a 1:1 metal:ligand ratio. Elemental analyses, stoichiometric and spectroscopic data of metal complexes indicated that the metal ions were coordinated to the sulphur (-SH) and/or (-OH) oxygen and imine nitrogen atoms (C = N). All of the data obtained from spectral, and molecular mechanics (MM2) or semi empirical calculations (AM1) studies support the structural properties of ligands and its Cu(II) and Ni(II) metal complexes.

Synthesis and Characterization of New Phthalocyanines Peripherally Fused to Four 21-Membered Dithiacrown Ether Macrocycles

Summary. A novel metal-free phthalocyanine and its nickel(II) and copper(II) phthalocyaninato complexes were prepared. The new compounds were characterized by elemental analyses, 1H- and 13C-NMR, IR, UV-Vis, and mass spectral data. The NMR and/or UV-Vis spectra of these compounds showed extremely broad bands and/or peaks. This phenomenon seems to be related to the presence of the sulfur substituents, which is consistent with the data observed for similar compounds. The absorption spectra of these compounds were greatly affected by aggregation processes.

Synthesis and Structural Studies of Hydrazone Dioxime Ligand and Its Cu(II) and Ni(II) Complexes

A hydrazone oxime (H2L) has been prepared in EtOH by reacting 2-hydrazine hydrate (2) with 2,3-butanedione monoxime (1). Homodinuclear copper(II), nickel(II), homotetranuclear copper(II), and heterotetranuclear copper(II)–nickel(II) complexes of H2L have been prepared. The metal complexes have been characterized by elemental analyses, magnetic moments, infrared (IR), ultraviolet–visible (UV-vis), and mass and thermal analyses studies. The dinuclear copper(II) and nickel(II) complexes of H2L were found to have a 1:1 metal:ligand ratio. In addition, total energy and heat formation for ligands (H2L and DHyLH2) by semiempirical PM3 calculations have shown that H2L is more stable than DHyLH2.

Models for copper proteins. Copper(I) and (II) complexes of a novel binucleating tetraamino-tetrathioether ligand

The novel binucleating ligand, 6,6 prime-methylene-bis(5 prime-amino-3 prime,4 prime-benzo-2 prime-thiapentyl)-1,11-diamino-2,3:9,10-dibenzo-4,8-dithiaundecane (H4L) was prepared and reacted with copper(II) salts in dry MeOH to yield mixtures of copper(I) and copper(II) complexes with Cl- and ClO-4 counter ions. The amine functions on the ligand release protons to form copper(I) complexes: (Cu2L)X2, where X=Cl−, ClO4-. The complexes were oxidized to (Cu2L)X4 with H2O2 in DMF; Cu(NO3)2 gave a different complex, [Cu2(H4L)(NO3)2](NO3)2, as regards proton releasing ability, coordination and oxidation number. Evidence for the structures of this new tetraamino-tetrathioether ligand and its copper complexes is provided by 1H-, 13C-n.m.r., mass, u.v.–vis., i.r. spectra, elemental analyses, molar conductivities and magnetic moments.The novel binucleating ligand, 6,6 prime-methylene-bis(5 prime-amino-3 prime,4 prime-benzo-2 prime-thiapentyl)-1,11-diamino-2,3:9,10-dibenzo-4,8-dithiaundecane (H4L) was prepared and reacted with copper(II) salts in dry MeOH to yield mixtures of copper(I) and copper(II) complexes with Cl- and ClO-4 counter ions. The amine functions on the ligand release protons to form copper(I) complexes: (Cu2L)X2, where X=Cl−, ClO4-. The complexes were oxidized to (Cu2L)X4 with H2O2 in DMF; Cu(NO3)2 gave a different complex, [Cu2(H4L)(NO3)2](NO3)2, as regards proton releasing ability, coordination and oxidation number. Evidence for the structures of this new tetraamino-tetrathioether ligand and its copper complexes is provided by 1H-, 13C-n.m.r., mass, u.v.–vis., i.r. spectra, elemental analyses, molar conductivities and magnetic moments.

Synthesis and Structural and Biochemical Activity Studies of Dioxime Ligand and its Mononuclear Cu(II), Ni(II), and Co(II) Complexes

A new tetradentate ligand incorporating dioxime moities has been synthesized. Its copper(II), nickel(II), and cobalt(II) complexes have been prepared and characterized by spectral methods. Elemental analyses and spectroscopic data of the metal complexes are consistent with the formation of the mononuclear copper(II), nickel(II) and cobalt(II) complexes. The crystal structure of the (2E, 2′E)-butane-2,3-dione 2,2′-{O 2,O 2′-[1,2-phenylenebis(methylene)]oxime compound (3) was determined by single-crystal x-ray diffraction technique. The free ligand and copper(II), nickel(II), and cobalt(II) complexes (5–7) were tested against the morphology of series bacteria. The Cu(II), Ni(II), and Co(II) complexes exhibit higher activity than dioxime ligand under identical experimental conditions.

Polymeric copper(II) and nickel(II) complexes of a tetraoxime containing a binucleating macrocycle ligand

Polymeric copper(II) and nickel(II) complexes of a binucleating tetraoxime macrocycle, 6,6′-methylene-bis[1,12-di(hydroximino)- 2,3;9,10-dibenzo-1,11-diaza-4,8-dithiacyclotridecane] (H4L), have been prepared and characterised by elemental analysis, magnetic moments, i.r., uv/vis., and e.p.r. spectral studies. I.r. spectra show that the ligand acts in a tetradentate manner and coordinates via N, S and O donor atoms. The geometry of the resulting metal chelates is discussed with the help of magnetic and spectroscopic measurements. The elemental analyses, stoichiometry and the spectroscopic data of the complexes indicate that the copper(II) and nickel(II) ions are coordinated by the coordination environment of the ligand. The spectral data suggest a distorted tetragonal geometry for polymeric copper(II), and nickel(II) ions in the complexes. The stoichiometry of the metal-to- H4L ratio of complexes (2) and (3), prepared from CuCl2 and NiCl2 respectively, was 3:1, suggesting the formation of polymeric species.