Crystal structure oftrans-(benzyl-C)bis(dimethylglyoximato-N,N′)-(morpholine-N)cobalt(III)-monohydrate

Summary The title compound crystallizes in the monoclinic space group P2₁/n, with cell dimensions:a = 8.535(4) Å,b = 13.009(4) Å,c = 20.615(5) Å, = 100.57(3) and Z = 4. The central cobalt atom coordination is a slightly distorted octahedron, formed by five N-atoms (two glyoximes and morpholine) and one C-atom.The interaction between the complex Co-units is weak: the strongest nearest neighbour interaction is formed by a hydrogen bridge in which the water molecule of crystallization acts as the donor part.     

Radiolysis of cobalt(III)-1,2 bis(beta-aminoethoxy)ethane N,N,N',N' sodium sulfonate triacetic acid chelate

Chelation studies of cobalt(III) with 1,2 bis(beta-aminoethoxy)ethane N,N,N',N' sodium sulfonate triacetic acid (ASTA) were performed. The results showed the effectiveness of ASTA as a chelating agent by using: molar ratio, continuous variation and slope ratio methods. Stable complex 1∶1 was formed at pH from 6.0 to 10.5. Solutions of Co-ASTA chelate of different molar ratios at pH 6.5 and 8.0 were irradiated by different gamma-radiation doses. The results showed a linear decrease of absorbance with gamma-radiation dose which can be utilized as a dosimeter for low dose rate measurement in the range studied. A proposed radiolytic mechanism is discussed. The degradation of the ASTA ligand has been related to hydroxyl radical attack.     

The first oxygen-bonded sulfenate ion: crystal and molecular structures of bis(ethylenediamine)(2-pyridinesulfenato-O)cobalt(III) and bis(ethylenediamine)(2-pyridinesulfinato-O)cobalt(III)

The first O-bonded sulfenate species [Co(en)2(py-SO-O)]2+ has been synthesized by isomerization of its S-bonded linkage isomer, [Co(en)2(pyridine-2-sulfenate-S]2+. The sulfenate ion in both forms is stabilized by coordination to the electropositive cobalt(III) ion. The driving force for the formation of the O-bonded sulfenate linkage isomer comes from the four to five membered ring expansion which accompanies the rearrangement. Crystal structures of the green O-sulfenate confirm the formulation and reveal varying amounts of a cocrystallized O-bonded sulfinate diastereomer. The cations have essentially identical structures except for the extra oxygen in the O-sulfinate. Differences in packing of cations and perchlorates give rise to two different structural types for the salts, corresponding to sulfenate-rich and sulfinate-rich phases.