scholarly journals Coordination Behavior of 3-Ethoxycarbonyltetronic Acid towards Cu(II) and Co(II) Metal Ions

2008 ◽  
Vol 2008 ◽  
pp. 1-6 ◽  
Author(s):  
Giorgos Athanasellis ◽  
Georgia Zahariou ◽  
Stefanos Kikionis ◽  
Olga Igglessi-Markopoulou ◽  
John Markopoulos
Keyword(s):  
Magnetic Susceptibility ◽  
Metal Ions ◽  
Metal Complexes ◽  
Pharmacological Activity ◽  
Epr Spectroscopy ◽  
Heterocyclic Compounds ◽  
Biological Systems ◽  
Coordination Behavior ◽  
Integral Role ◽  
Complexation Reactions

Tetronic acids, 4-hydroxy-5H-furan-2-ones, constitute a class of heterocyclic compounds with potent biological and pharmacological activity. Theβ,β′-tricarbonyl moiety plays an integral role in biological systems and forms a variety of metal complexes. In this report, we present the complexation reactions of 3-ethoxycarbonyl tetronic acids with acetates and chlorides of Cu(II) and Co(II). These complexes have been studied by means of EPR spectroscopy and magnetic susceptibility measurements. From the obtained results, a preliminary complexation mode of the ligand is proposed.

Studies on complexes of VO(II), Mn(II), Cu(II), Ni(II), Co(II), Zn(II), Fe(III), and UO2(II) with hydrazone β-diketone ligands

1990 ◽  
Vol 68 (5) ◽  
pp. 774-781 ◽  
Author(s):  
Mohamed S. Abdel-Moez ◽  
Shaker L. Stefan ◽  
Mostafa M. El-Behairy ◽  
Mohamed M. Mashely ◽  
Basheir A. El-Shetary
Keyword(s):  
Magnetic Susceptibility ◽  
Transition Metal ◽  
Ir Spectra ◽  
Metal Ions ◽  
Metal Complexes ◽  
Stability Constants ◽  
Transition Metal Complexes ◽  
Elemental Analysis ◽  
Water Solvent ◽  
Uv Visible

The stepwise stability constants of VO(II), Mn(II), Cu(II), Ni (II), Co(II), Zn(II), Fe(III), and UO2(II) metal ions with 2-(2-acetylphenylhydrazone)-5,5-dimethyl-1,3-cyclohexane dione (2-APHDm), 3-(2-acetylphenylhydrazone)pentane-2,4-dione (2-APHA), 2-(2-acetylphenylhydrazone)-1-phenyl-1,3-butane dione (2-APHB), 2-(2-acetylphenylhydrazone)-1,3-diphenyl-1,3-propane dione (2-APHDB), and 3-(2-acetylphenylhydrazone)-1,1,1-trifluoropentane-2,4-dione (2-APHTA) were determined at 30 °C by pH titrations in 75% (v/v) dioxane–water solvent. In addition, metal complexes of three related β-diketones, 2-APHA, 2-APHB, and 2-APHDB have been synthesized and characterized by elemental analysis, uv–visible, ir spectra, and conductance in DMF and magnetic susceptibility measurements. The structure of the complexes have been proposed. Keywords: transition metal complexes of hydrazone-β-diketone ligands.

Synthesis and Structural Systematics of First-Row Transition Metal Complexes with 2-[Bis(benzimidazol-2-ylmethyl)amino]ethanol

1987 ◽  
Vol 42 (10) ◽  
pp. 1307-1314 ◽  
Author(s):  
Kazuhiro Takahashi ◽  
Yuzo Nishida
Keyword(s):  
Transition Metal ◽  
Metal Ions ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Structural Parameters ◽  
Biological Systems ◽  
Tridentate Ligand ◽  
Crystal Data ◽  
Space Group ◽  
Distorted Octahedral

Abstract A nickel(II) complex with (bbimae) (= 2-[bis(benzimidazol-2-ylmethyl)amino]ethanol), [Ni(bbimae)(NCS)2] · H2O (1) and an oxovanadium(IV) complex, [VO(bbimae)(NCS)2] · dma (dma = N.N-dimethylacetamide) (2) have been prepared and their crystal structures determined by X-ray diffraction. Crystal data for 1 at 293 K: a = 13.334(2). b = 17.048(2), c = 10.3829(9) Å, space group P212121, Z = 4, and dcalcd = 1.41 gcm-3. Crystal data for 2 at 293 K: a = 14.099(2). b = 14.998(4), c = 14.051(2) Å, β = 107.634(9)°, space group P21/c, Z = 4, and dcalcd = 1.36 gcm-3. In the nickel(II) complex, (bbimae) functions as a tetradentate ligand, and the geometry around Ni(II) ion is best described as distorted octahedral. The structure is very similar to those of the correspond­ing Co(II) and Mn(II) complexes. In the case of 2, which is also distorted octahedral, (bbimae) is a tridentate ligand without the coordination of the alcohol group. The M-N (benzimidazole) distances are in the range of 1.95-2.18 Å, and also observed for other first-row transition metal complexes with (bbimae). and differ in the order V(IV) < Mn(II) > Co(II) > Ni(II) > Cu(II). consistent with effective ionic radii of the metal ions. Comparison of the structural parameters of these complexes with those of the metal ions in biological systems has supported the usefulness of the tripod-like ligands to synthesis model compounds for biological systems.

scholarly journals Complexes With Biologically Active Ligands. Part 101 Inhibition of Carbonic Anhydrase Isozymes I and II With Metal Complexes of Imidazo[2,1−b]-1,3,4-Thiadiazole-2-Sulfonamide

1997 ◽  
Vol 4 (1) ◽  
pp. 19-26 ◽  
Author(s):  
Andrea Scozzafava ◽  
Claudiu T. Supuran
Keyword(s):  
Carbonic Anhydrase ◽  
Metal Ions ◽  
Metal Complexes ◽  
Elemental Analysis ◽  
Epr Spectroscopy ◽  
Title Compound ◽  
Biologically Active ◽  
Standard Procedures

The title compound was prepared by an improved variant of the literature procedure, and metal complexes containing its anion and the following metal ions: Zn(II), Cd(II), Hg(II), Co(II), Ni(II), Cu(II), V(IV), Fe(III) and Ag(I) were synthesized and characterized by standard procedures (elemental analysis; IR, electronic, NMR and EPR spectroscopy; TG, magnetic and conductimetric measurements). The parent sulfonamide and its metal complexes are potent inhibitors of two carbonic anhydrase (CA) isozymes, CA I and II, and they might possess applications as selective cerebrovasodilating agents.

scholarly journals Synthesis and Study of Mixed Ligand-Metal Complexes of 1, 3, 7-Trimethylxanthine and 1, 3-Dimethyl-7H-purine-2, 6-dione with Some Other Ligands

2011 ◽  
Vol 8 (1) ◽  
pp. 153-158 ◽  
Author(s):  
Shayma A. Shaker
Keyword(s):  
Magnetic Susceptibility ◽  
Infrared Spectroscopy ◽  
Nitrogen Atom ◽  
Oxygen Atom ◽  
Metal Ions ◽  
Metal Complexes ◽  
Mixed Ligand ◽  
Thiocyanate Ion ◽  
Elemental Analyses ◽  
Uv Visible

This work presents synthesis and study of a new mixed ligand metal complexes of 1,3,7-trimethylxanthine and 1,3-dimethyl-7H-purine-2,6-dione with some other ligands like SCN and OCN ions to give the general formula [M(Tx)2(Tp) )2XY] where M=Co(II), Ni(II), Cu(II), Zn(II) and Cd(II), Tx=1,3,7-trimethylxanthine, Tp= 1,3-dimethyl-7H-purine-2,6-dione, X= SCN and Y= OCN. The resulting products were found to be solid which have been characterized using UV-Visible and infrared spectroscopy. Elemental analyses were performed using C, H, N analysis and atomic absorption techniques. The magnetic susceptibility and the conductivity were also measured. The present results suggest that the 1,3,7-trimethylxanthine and 1,3-dimethyl-7H-purine-2,6-dione were coordinated with metal ions through the nitrogen atom. Thiocyanate ion was coordinated with metal ions through the sulfur atom and the cyanate ion was coordinated with metal ions through the oxygen atom.

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