scholarly journals Toxicological assessment of synthesized and characterized transition metal(II) complexes of eflornithine hydrochloride hydrate on albino rats

2021 ◽  
Vol 34 (3) ◽  
pp. 489-500
Author(s):  
W. A. Osunniran ◽  
J. A. Obaleye ◽  
A. C. Tella ◽  
Y. O. Ayipo ◽  
A. T. Bale ◽  
...  
Keyword(s):  
Magnetic Susceptibility ◽  
Transition Metal ◽  
Metal Complexes ◽  
Amino Nitrogen ◽  
Albino Rats ◽  
Ionization Mass ◽  
Toxicological Evaluation ◽  
Toxicological Assessment ◽  
Carboxylate Oxygen ◽  
High Level

Transition metal complexes of Cu(II), Co(II) and Ni(II) with eflornithine hydrochloride hydrate (EFN), an antitrypanosomiasis drug, as ligand have been synthesized and characterized by melting point, elemental analysis, Fourier transform infrared (FTIR), electronic spectra, magnetic susceptibility and electrospray ionization mass spectrometry (ESI-MS). The FTIR spectral data suggested the coordination modes of the ligand to be bidentate, coordinated to the metal ions through its carboxylate oxygen atom and an amino nitrogen atom. From the microanalytical data, the stoichiometry of the metal complexes is 1:2 (metal to ligand). The electronic absorption and magnetic susceptibility studies generally suggested octahedral geometry for the metal complexes. Toxicological evaluation of the ligand (EFN) and complexes were carried out using albino rats. Twenty-five albino rats that were used for the experiment were randomly divided into five groups and animals in group 1 served as a control. All the animals were sacrificed twenty-four hours after completion of their doses. The results revealed a high level of toxicity of EFN than the synthesized metal complexes.                     KEY WORDS: Eflornithine hydrochloride hydrate, Carboxylate moiety, Antitrypanosomiasis drug, Toxicological evaluation, Albino rats   Bull. Chem. Soc. Ethiop. 2020, 34(3), 489-500. DOI: https://dx.doi.org/10.4314/bcse.v34i3.6

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.

scholarly journals A New Twist on an ‘Old’ Ligand: A [Mn16] Double Square Wheel and a [Mn10] Contorted Wheel

2020 ◽  
Author(s):  
Euan Brechin ◽  
Constantinos J. Milios ◽  
Thomais Tziotzi ◽  
Marco Coletta ◽  
Mark Gray ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Direct Current ◽  
Coordination Compounds ◽  
Exchange Interactions ◽  
Ligand Design ◽  
Jahn Teller

Ligand design remains key to the synthesis of coordination compounds possessing specific topologies, nuclearities and symmetries that direct targeted physical properties. N,O-chelates based on ethanolamine have been particularly prolific in constructing a variety of paramagnetic 3d transition metal complexes with fascinating magnetic properties. Here, we show that combining three ethanolamine moieties within the same organic framework in the form of the ligand 1,3,5-tri(2-hydroxyethyl)-1,3,5-triazacyclohexane (LH3) leads to the formation of two highly unusual Mn wheels. Reaction of Mn(NO3)2·6H2O with LH3 in basic methanolic solutions leads to the formation of [MnIII 12MnII 4(µ3-O)6(µ-OH)4(µ3-OMe)2(µOMe)2(L)4(LH)2(H2O)10](NO3)6(OH)2 (1) and [MnIII 10(µ3-O)4(µ-OH)4(µ-OMe)4(L)4(H2O)4](NO3)2 (2); the only difference in the synthesis being the ratio of metal:ligand employed. The structure of the former describes two offset [MnIII 6MnII 2] square wheels, linked through a common centre, and the latter a single [MnIII 10] wheel twisted at its centre, such that the top half is orientated perpendicular to the bottom half. In both cases the L 3- /LH2- ligands dictate the orientation of the Jahn-Teller axes of the MnIII ions which lie perpendicular to the triazacyclohexane plane. Direct current magnetic susceptibility and magnetisation data reveal the presence of competing exchange interactions in 1 and strong antiferromagnetic interactions in 2. Given the simplicity of the reactions employed and the paucity of previous work, the formation of these two compounds suggests that LH3 will prove to be a profitable ligand for the synthesis of a multitude of novel 3d transition metal complexes

scholarly journals FIRST-ROW TRANSITION METAL COMPLEXES OF OMEPRAZOLE AS ANTI-ULCERATIVE DRUGS

2010 ◽  
Vol 10 (3) ◽  
pp. 382-389
Author(s):  
Suman Malik ◽  
Supriya Das ◽  
Bharti Jain
Keyword(s):  
Magnetic Susceptibility ◽  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Analytical Data ◽  
Transition Metal Ions ◽  
Molar Conductivity ◽  
Spectral Studies ◽  
Antibacterial And Antifungal Activities ◽  
Antibacterial And Antifungal

Omeprazole (OME) is a proton pump inhibitor (PPI). PPIs have enabled to improve the treatment of various acid-peptic disorders. OME is a weak base and it can form several complexes with transition and non-transition metal ions. In the present paper, we are describing series of transition metal complexes of omeprazole i.e., 5-methoxy-2[(4methoxy-3, 5dimethyl-2-pyridinyl) methylsulfinyl]-1H-benzimidazole with CuII, MnII, CoII, NiII, FeII, ZnII and HgII. These complexes were characterized by elemental analysis, molar conductivity, IR, NMR, magnetic susceptibility, UV-visible spectral studies, ESR, SEM and X-ray diffraction. Based on the above studies, the ligand behaves as bidentate O, N donor and forms coordinate bonds through C=N and S=O groups. The complexes were found to non-electrolytic in nature on the basis of low values of molar conductivity. Analytical data and stoichiometry analysis suggest ligand to metal ratio of 2:1 for all the complexes. Electronic spectra and magnetic susceptibility measurements reveal octahedral geometry for Mn(II),Co(II), Ni(II),Fe(II) and Cu(II) complexes and tetrahedral for Hg(II) and Zn(II) complexes. Ligands and their metal complexes have been screened for their antibacterial and antifungal activities against bacteria Pseudomonas, Staphylococcus aureus and fungi Aspergillus niger and A. flavous.

scholarly journals High-Spin Cobalt(II) Complex with Record-Breaking Anisotropy of the Magnetic Susceptibility According to Paramagnetic NMR Spectroscopy Data

2021 ◽  
Vol 47 (1) ◽  
pp. 10-16
Author(s):  
Ya. A. Pankratova ◽  
Yu. V. Nelyubina ◽  
V. V. Novikov ◽  
A. A. Pavlov
Keyword(s):  
Magnetic Susceptibility ◽  
Nmr Spectroscopy ◽  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Single Molecule ◽  
Functional Materials ◽  
Medical Diagnostics ◽  
Paramagnetic Nmr ◽  
Single Molecule Magnets

Abstract The tetrahedral cobalt(II) complex [CoL2](HNEt3)2 (I), where L is 1,2-bis(methanesulfonamido)benzene, exhibiting the properties of a single-molecule magnet is synthesized and characterized. The electronic structure parameters of complex I are determined by paramagnetic NMR spectroscopy. They completely reproduce the results of less available methods of studying single-molecule magnets. The value of axial anisotropy of the magnetic susceptibility estimated for complex I (Δχax = 34.5 × 10–32 m3 at 20°C) is record-breaking among all transition metal complexes studied by the NMR method, which provides wide possibilities for the use of complex I as a paramagnetic label for structural biology or as a contrast agent and even a temperature sensor for medical diagnostics. The data obtained indicate the advantages of paramagnetic NMR spectroscopy as a method of investigation of the magnetic properties and electronic structures of highly anisotropic transition metal complexes, which are precursors of many functional materials.

Transition Metal Complexes of Ambidinourea and Related Ligands.

1969 ◽  
Vol 24 (12) ◽  
pp. 1514-1517 ◽  
Author(s):  
A. Syamal
Keyword(s):  
Magnetic Susceptibility ◽  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Electronic Spectra ◽  
Strong Field ◽  
Absorption Bands ◽  
Effect Of Solvents ◽  
Infra Red ◽  
Solid Complexes

Copper (II), nickel (II), and palladium (II) complexes of amidinourea are reinvestigated in order to verify their structure. Electronic spectra and magnetic susceptibility measurements have been obtained on the solid complexes. Electronic spectral results indicate the donor strength of amidinourea is comparable to strong field ligands like biuret, biguanide, and I-amidino-O-alkylurea. Infra-red spectral results suggest that the carbonyl group of amidinourea is not involved in coordination and the donor atoms in amidinourea are amide nitrogens. The effect of solvents on the absorption bands is also discussed. The solution absorption spectra of bis (amidinourea) copper (II) chloride in different solvents indicate the following order of decreasing tetragonality:DMSO > methanol > ethyleneglycol > water.

Catalytic activation of nitrogen derivatives with transition-metal complexes

2006 ◽  
Vol 78 (2) ◽  
pp. 363-375 ◽  
Author(s):  
Hélène Lebel ◽  
Olivier Leogane ◽  
Kim Huard ◽  
Sylvain Lectard
Keyword(s):  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Curtius Rearrangement ◽  
Catalytic Activation ◽  
Transition Metal Catalyzed ◽  
Metal Catalyzed ◽  
High Level

Studies regarding the transition-metal-catalyzed decomposition of nitrogen derivatives toward Curtius rearrangement and the formation of nitrenes which undergo C-H insertion and aziridination reactions are presented. These processes lead to the formation of C-N bond with a high level of selectivity and efficiency.

Sign in / Sign up

Export Citation Format

Share Document