Bis[3-chloro-6-(3,5-dimethyl-1H-pyrazol-1-yl)picolinato]nickel(II) tetrahydrate
In the title complex, [Ni(C11H9ClN3O2)2]·4H2O, the Ni atom is coordinated by four N atoms and two O atoms derived from two tridentate 3-chloro-6-(3,5-dimethyl-1H-pyrazol-1-yl)picolinate ligands. The cis-N4O2 donor set defines a distorted octahedral geometry. In the crystal structure, the complex and water molecules are linked by O—H⋯O hydrogen bonds.
Aquatris[6-(3,5-dimethyl-1H-pyrazol-1-yl)picolinato]-κ6 N,N′,O;κO-dysprosium(III) trihydrate
In the title complex, [Dy(C11H10N3O2)3(H2O)]·3H2O, the DyIII atom is coordinated by four N atoms and four O atoms derived from three tridentate deprotonated 6-(3,5-dimethyl-1H-pyrazol-1-yl)picolinate ligands and one water molecule. The complex and solvent water molecules are linked together via O—H⋯O, O—H⋯N, C—H⋯O and C—H⋯π hydrogen-bonding interactions, forming a three-dimensional network structure.
Sterol metabolism. XLI. Cholesterol A-ring autoxidations
Abstract Chromatographic and spectral evidence is adduced for the presence of cholest-5-en-3-one, cholest-4-en-3-one, and cholest-4-ene-3,6-dione in samples of cholesterol aged naturally in air or subjected to irradiation in air by 60 Co gamma radiation. These findings establish an additional mode of air oxidation of cholesterol to A-ring 3-ketones. Moreover, the oxidation by air of cholest-5-en-3-one induced by 60 Co gamma radiation yielded cholest-4-en-3-one, cholest-4-ene-3,6-dione, and the epimeric 3-oxocholest-4-ene-6-hydroperoxides. Cholest-4-en-3-one was not altered by irradiation in air, nor was cholesterol isomerized to cholest-4-en-3β-ol upon irradiation. From these observations it is deduced that the radiation-induced A-ring dehydrogenation of cholesterol yields initially cholest-5-en-3-one which upon isomerization yields cholest-4-en-3-one not further oxidized and which by a second oxidation yields the epimeric 3-oxocholest-4-ene-6-hydroperoxides which decompose to cholest-4-ene-3,6-dione.