51 research outputs found
Synthesis and characterization of monomeric manganese(II) and cobalt(III) complexes of the hexadentate amine ligand N,N,N',N'-tetrakis(2-pyridylmethyl)ethane-1,2-diamine, C26H28N6 (tpen)
The syntheses and characterization of complexes of manganese(II) and cobalt(III) with the potentially hexadentate ligand N,N,N',N'-tetrakis(2-pyridylmethyl)ethane-1,2-diamine, C26H28N6 (tpen), are described. The monomeric manganese(II) complex [Mn(C26H28N6)(H2O)](ClO4)2 (1) crystallizes in the monoclinic space group C2/c with 4 formula units in a cell of dimensions a = 15.080(1) Å, b = 10.101(1) Å, c = 19.426(2) Å and b = 94.6l(l)°. The structure has been refined to a final value of the conventional R-factor of 0.0401 based on 2586 observed independent reflections. The geometry at the manganese center is seven-coordinate, and is best described as a capped trigonal pyramid with the water molecule forming the cap and the six nitrogen atoms of the tpen ligand occupying the pyramidal sites. The manganese atom and the water molecule lie on a crystallographic twofold axis. The related cobalt(III) complex, [Co(C26H28N6)] (C1O4)3 (4) crystallizes in the monoclinic space group P21/n with 4 formula units in a cell of dimensions a = 9.829(2) Å, b = 18.364(4) Å, c = 18.128(4) Å and b = 93.64(3)°. The structure has been refined to a final value of the conventional R-factor of 0.0526 based on 3574 observed independent reflections. The complex is approximately octahedral, the coordination being provided by the six nitrogen atoms of the tpen ligand. The EPR spectrum of 1 diluted into the corresponding Cd(II) host has been simulated with the parameters g = 2.00, A = 0.0080 cm-1, D = 0.116 cm-1, and E = 0.0013 cm-1. The small value of E/D is consistent with the observed symmetry of the complex. KEY WORDS: Monomeric manganese(II) complex, Monomeric cobalt(III) complex, Hexadentate ligand, N,N,N',N'-tetrakis(2-pyridylmethyl)ethane-1,2-diamine Bull. Chem. Soc. Ethiop. 2004, 18(1), 17-28.
Single Crystal Electron Paramagnetic Resonance Spectra of Cs<sub>2</sub>MnF<sub>6</sub> and K<sub>2</sub>MnF<sub>6</sub> Diluted in the Isomorphous Germanium Salts:Ingen
Magnetic Susceptibility and EPR Spectra of (µ-Hydroxo)bis[pentaammineChromium(III)] Chloride Monohydrate
Magnetic Susceptibility and EPR Spectra of μ-Cyano-bis(pentaamminechromium(III)) Perchlorate
Magnetic Susceptibility and EPR Spectra of mu-Cyano-bis[pentaamminechromium(III)]Perchlorate
Magnetic Susceptibility and EPR Spectra of (μ-Hydroxo)bis[pentaamminechromium(III)] Chloride Monohydrate
Magnetism, Spectroscopy and Structure of Tri-μ-hydroxobis{[N,N',N''-trimethyl-1,1,1-tris(aminomethyl)ethane]chromium(III)} Chloride Tetrahydrate R = 0.034 and Rw = 0.047
Synthesis and Magnetic Susceptibility of Novel Types of Bimetallic, Octanuclear, Cubane-Structured Complex Ions Containing Molybdenum (IV)/Tungsten(VI) and Chromium(III)/Cobalt(III)
Synthesis and Crystal Structure of a Compound with Three [2<sup>4</sup>.3<sub>1</sub>] Adamanzanecopper(II) Species Coordinated to One Carbonate Ion, µ<sub>3</sub>-Carbonatotris-{1,4,7,10-tetraazabicyclo[5.3] pentadecanecopper(II)} perchlorate dihydrate
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