scholarly journals Catalytic Hydrogenation of Sorbic Acid using Pyrazolyl Palladium(II) and Nickel(II) Complexes as Precatalysts

2021 ◽  
Vol 74 ◽  
Author(s):  
Oluwasegun E. Olaoye ◽  
Olayinka Oyetunji ◽  
Banothile C.E. Makhubela ◽  
Apollinaire Muyaneza ◽  
Gopendra Kumar ◽  
...  
Keyword(s):  
Catalytic Hydrogenation ◽  
Sorbic Acid ◽  
Nickel Complexes ◽  
Experimental Conditions ◽  
Acid Proceeds ◽  
Hydrogenation Selectivity

ABSTRACT We have prepared several pyrazolyl palladium and nickel complexes ([(L1)PdCl2](1), [(L2) PdCl2](2), [(L3) PdCl2](3), [(L1) NiBr2](4), [(L2) NiBr2](5) and [(L3) NiBr2](6)) by reacting 3,5-dimethyMH-pyrazole (L1), 3,5-di-ferf-butyl-1ZÏ-pyrazole (L2) and 5-ferrocenyl-1Zf-pyrazole(L3) with [PdCl2(NCMe)2] or [NiBr2(DME)] to afford mononuclear palladium and nickel complexes, respectively. These complexes were then investigated as pre-catalysts in the hydrogenation of 2,4-hexadienoic acid (sorbic acid). The active catalysts from these complexes demonstrate significant activities under mild experimental conditions. Additionally, the active catalysts show that the hydrogenation of sorbic acid proceeds in a sequential manner, where the less hindered C=C bond (4-hexenoic acid) is preferentially reduced over the more hindered C=C bond (2-hexenoic acid). Keywords: Pyrazolyl catalysts, sorbic acid, hydrogenation, selectivity.

Catalytic hydrogenation of binary and ternary mixtures of unsaturated substances in the liquid phase on platinum

1979 ◽  
Vol 44 (8) ◽  
pp. 2378-2383 ◽  
Author(s):  
Libor Červený ◽  
Radka Junová ◽  
Vlastimil Růžička
Keyword(s):  
Liquid Phase ◽  
Binary Mixtures ◽  
Silica Gel ◽  
Catalytic Hydrogenation ◽  
Ternary Systems ◽  
Ternary Mixtures ◽  
Unsaturated Alcohol ◽  
Solvent Concentration ◽  
Binary And Ternary Mixtures ◽  
Hydrogenation Selectivity

Hydrogenation of olefinic substrates in binary and ternary mixtures using 5% Pt on silica gel as the catalyst was studied in normal conditions in the liquid phase with methanol or cyclohexane or in solvent-free systems. The effect of the solvent concentration on the selectivity of hydrogenation of the unsaturated alcohol-olefin binary mixtures was investigated. In ternary systems of unsaturated substrates, the effect of each of the substrates on the selectivity of hydrogenation of the remaining two substances was examined. Another system was found in which a jump change of the hydrogenation selectivity occurred on the vanishing of the fastest reacting substance.

Stereoselective catalytic hydrogenation of sorbic acid and sorbic alcohol with new Cp*Ru complexes

2000 ◽  
pp. 217-218 ◽  
Author(s):  
Stephan Steines ◽  
Birgit Drießen-Hölscher ◽  
Ulli Englert
Keyword(s):  
Catalytic Hydrogenation ◽  
Sorbic Acid ◽  
Ru Complexes

ChemInform Abstract: Stereoselective Catalytic Hydrogenation of Sorbic Acid and Sorbic Alcohol with New Cp*Ru Complexes.

ChemInform ◽  
2010 ◽  
Vol 31 (19) ◽  
pp. no-no
Author(s):  
Stephan Steines ◽  
Ulli Englert ◽  
Birgit Driessen-Hoelscher
Keyword(s):  
Catalytic Hydrogenation ◽  
Sorbic Acid ◽  
Ru Complexes

Homogeneous catalytic hydrogenation of sorbic acid with pentacyanocobaltate II

1964 ◽  
Vol 41 (2) ◽  
pp. 153-158 ◽  
Author(s):  
A. F. Mabrouk ◽  
H. J. Dutton ◽  
J. C. Cowan
Keyword(s):  
Catalytic Hydrogenation ◽  
Sorbic Acid

Transition metal complexes of dithioacetylacetone and diselenoacetylacetone: syntheses, properties, and infrared spectra

1969 ◽  
Vol 22 (5) ◽  
pp. 891 ◽  
Author(s):  
CG Barraclough ◽  
RL Martin ◽  
IM Stewart
Keyword(s):  
Transition Metal Complexes ◽  
Nickel Complexes ◽  
Bidentate Ligand ◽  
Mixed Complex ◽  
Normal Coordinate ◽  
Experimental Conditions ◽  
Divalent Nickel ◽  
Related Series ◽  
Infrared Absorption Spectra ◽  
Cobalt And Nickel

The synthesis and properties of some cobalt(II) and nickel(II) complexes of dithioacetylacetone and diselenoacetylacetone are described. Unlike the corresponding acetylacetonates, the cobalt and nickel complexes are square-coordinated monomers with ground states of spin S = 1/2 and S = 0, respectively. For divalent nickel, the isolation of a mixed complex containing one monothioacetylacetonate and one dithioacetylacetonate bidentate ligand completes the NiS2O2, NiS3O, NiS4 series of diamagnetic monomers. � A tentative mechanism is proposed for the course of the reaction which leads to these compounds under the experimental conditions first formulated by Martin and Stewart. The infrared absorption spectra have been assigned on the basis of a normal coordinate analysis taken in conjunction with the unusually favourable circumstances offered by a closely related series of square-coordinated monomers [Cu(acac)2], [Co(SacSac)2], [Ni(SeacSeac)2].

Electrolytic Isolation of Twin-Type Shock Deformation Structures

1967 ◽  
Vol 25 ◽  
pp. 318-319
Author(s):  
F. I. Grace ◽  
L. E. Murr
Keyword(s):  
Grain Boundaries ◽  
Thin Foil ◽  
Electrolyte Composition ◽  
Experimental Conditions ◽  
Average Current Density ◽  
Electron Transmission ◽  
Deformation Structures ◽  
The Matrix ◽  
Average Current ◽  
Specimen Edge

During the course of electron transmission investigations of the deformation structures associated with shock-loaded thin foil specimens of 70/30 brass, it was observed that in a number of instances preferential etching occurred along grain boundaries; and that the degree of etching appeared to depend upon the various experimental conditions prevailing during electropolishing. These included the electrolyte composition, the average current density, and the temperature in the vicinity of the specimen. In the specific case of 70/30 brass shock-loaded at pressures in the range 200-400 kilobars, the predominant mode of deformation was observed to be twin-type faults which in several cases exhibited preferential etching similar to that observed along grain boundaries. A novel feature of this particular phenomenon was that in certain cases, especially for twins located in the vicinity of the specimen edge, the etching or preferential electropolishing literally isolated these structures from the matrix.

Site of Lysosome Production During Hepatic Injury

1969 ◽  
Vol 27 ◽  
pp. 348-349
Author(s):  
Nalin J. Unakar
Keyword(s):  
Electron Microscopy ◽  
Golgi Apparatus ◽  
Mouse Liver ◽  
Hepatic Injury ◽  
Close Approximation ◽  
Experimental Conditions ◽  
Toxic Injury

The increased number of lysosomes as well as the close approximation of lysosomes to the Golgi apparatus in tissue under variety of experimental conditions is commonly observed. These observations suggest Golgi involvement in lysosomal production. The role of the Golgi apparatus in the production of lysosomes in mouse liver was studied by electron microscopy of liver following toxic injury by CCI4.

Optimizing conditions for x-ray microchemical analysis in analytical electron microscopy

1978 ◽  
Vol 36 (1) ◽  
pp. 548-549 ◽  
Author(s):  
N. J. Zaluzec
Keyword(s):  
Solid Angle ◽  
Analytical Electron Microscopy ◽  
Incident Beam ◽  
Thin Foil ◽  
Experimental Conditions ◽  
X Ray ◽  
Microchemical Analysis ◽  
Analytical Electron ◽  
Image Position ◽  
Incident Beam Energy

The ultimate sensitivity of microchemical analysis using x-ray emission rests in selecting those experimental conditions which will maximize the measured peak-to-background (P/B) ratio. This paper presents the results of calculations aimed at determining the influence of incident beam energy, detector/specimen geometry and specimen composition on the P/B ratio for ideally thin samples (i.e., the effects of scattering and absorption are considered negligible). As such it is assumed that the complications resulting from system peaks, bremsstrahlung fluorescence, electron tails and specimen contamination have been eliminated and that one needs only to consider the physics of the generation/emission process.The number of characteristic x-ray photons (Ip) emitted from a thin foil of thickness dt into the solid angle dΩ is given by the well-known equation

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