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Hydrogenation of ligninBloom, Edward Stanton, January 1939 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1939. / Typescript. Includes abstract and vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaf 45).
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The hydrogenation of nitrobenzene over metal catalystsGelder, Elaine A. January 2005 (has links)
Thesis (Ph.D.) - University of Glasgow, 2005. / Includes articles from journals : Catalysis Letters, vol. 84, nos. 3-4, 2002, pp. 205-208 and Chemical Communications, 2005, pp. 522-524. Includes bibliographical references (p. 305-311). Print version also available. Mode of access : World Wide Web. System requirements : Adobe Acrobat reader required to view PDF document.
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The hydrogenation of some condensation products of acetoneSheridan, William R, January 1900 (has links)
Thesis (Ph. D.)--Catholic University of America. / Biography.
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Catalytic hydrogenation of nitrilesJuday, Richard Evans, January 1943 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1943. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaf [62]).
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Phosphine ligands for fluorous biphasic catalysisShepperson, Ian January 2002 (has links)
No description available.
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Phosphine ligands for fluorous biphase catalysisCaldas, Hugo de Sousa Machado Feliciano January 2003 (has links)
No description available.
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Complexation and hydrogenation of olefins by chlororuthenate (II) in aqueous acid solutionKing, Roy James January 1973 (has links)
The formation of 1:1 π-complexes between chlororuthenate(II) and a series of substituted ethylenes in aqueous hydrochloric acid solution is described. Kinetic studies of the complexation for maleic, acrylic and crotonic acid substrates are presented.
The likely mechanism is a two step process involving an initial S[subscript]N¹ dissociation of a chlororuthenate(II) complex or complexes. The nature of the blue chlororuthenate(II) species is uncertain and this prevents resolution of some questions about the mechanism; however, observations on the behavior of the blue solutions and some suggestions as to their possible nature are given. Acrylic and crotonic acids are hydrogenated catalytically via the ruthenium(II) π-complexes.
Crotonaldehyde and crotonitrile complexes of chlororuthenate(II) are not hydrogenated but undergo hydration and/or polymerization. Kinetic data for the hydrogenation of the organic acids fit a well established mechanism. The factors which influence reaction rates in the hydrogenation steps are thoroughly discussed. / Science, Faculty of / Chemistry, Department of / Graduate
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Activation of molecular hydrogen in solution by complexes of univalent, divalent, and trivalent rutheniumHui, Benjamin Ching-Yue January 1969 (has links)
Kinetic studies of a number of interesting and significant reactions involving reaction of molecular hydrogen, olefins and carbon monoxide with solutions of ruthenium chloride complexes are described.
Ruthenium trichloride trihydrate, "RuCl₃.3H₀0", which is a mixture of ruthenium(III) and ruthenium(IV), was found to react with molecular hydrogen in dimethylacetamide (DMA) solution under mild conditions, to produce ruthenium(II) and ruthenium(I) in successive steps involving activation of the hydrogen by ruthenium(III) and ruthenium(II): [forumulae omitted]
In aqueous acid solution, the reverse of reaction (1) prevents reduction of ruthenium(III); in DMA, a more basic solvent, the released proton is stabilized and reduction is observed all the way to the univalent state. Convincing evidence was found for the existence of ruthenium(I) in DMA, although no well-characterized ruthenium(I) solid complexes were isolated. The present studies are the first reported on the solution chemistry of ruthenium(I) chlorides.
Ruthenium(I) chloride complexes in DMA (80°) were found to activate molecular hydrogen through dihydride formation for the catalyzed reduction of olefins. The following mechanism is indicated: [formulae omitted]
Accompanying olefin isomerization and some deuterium isotope studies suggest that reaction (5) goes through an ϭ-alkyl hydride intermediate, the hydrogen transfer process involving two consecutive single hydrogen atom transfers to a coordinated olefin. Addition of triphenylphosphine (PPh₃) to the ruthenium(I) catalyst solution decreases the hydrogenation rate. However, reaction of hydrogen with a ruthenium(I) solution containing
PPh₃ and no substrate gave evidence for the formation of a hydride species.
In the presence of PPh₃, reaction of H₂ with ruthenium(II) chloride in DMA does not produce ruthenium(I). The ruthenium(II) hydride intermediate is stabilized by the phosphine ligand yielding the well-known complex RuHCl(PPh₃)₃ which has been found to be extremely active in catalyzing the hydrogenation of olefins. An extremely simple method for the preparation of the catalyst "in situ" is demonstrated, again utilising the basic properties of DMA. A mechanism involving a predissociation of the catalyst, and formation of an ϭ-alkyl intermediate is thought to be operative in the catalyzed hydrogenation of olefins: [formulae omitted]
Both ruthenium(I) and ruthenium(II) chlorides in DMA were
found to absorb carbon monoxide readily at ambient temperatures,
producing Ru[superscript I](CO) and Ru[superscript I](CO)₂, and Ru[superscript II](CO) and Ru[superscript II](CO)₂respectively.
The introduction of carbonyl groups into these ruthenium complexes was
found to inhibit catalytic activity for the hydrogenation of olefins.
The anion [RuCI₄(bipyridine)]²⁻ , in 3 M HC1, was found to be a hydrogenation catalyst for olefin reduction, though not a very efficient one. A mechanism similar to the RuHCl(PPh₃)₃ catalyzed system seems to be involved, and is quite different to that reported for a corresponding system involving the tetrachlororuthenate(II) complex, [RuCI₄]²⁻. / Science, Faculty of / Chemistry, Department of / Graduate
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Homogeneous hydrogenation catalysed by square planar iridium (I) complexesMemon, Nazir Ahmed January 1967 (has links)
A study is described of the kinetics of reactions in which the complexes trans-Ir (CO)X(PPh₃)₂, where X = Cl, Br and I, are used for the catalytic homogeneous hydrogenation of olefins, in particular maleic acid. The catalytic activity is poor in benzene solutions but is enhanced in coordinating solvents such as N, N'-dimethylacetamide. The kinetics were studied by measurements of hydrogen uptake, at various experimental conditions in which iridium, olefin and hydrogen concentrations were varied.
The rate-law is complex showing between zero and first order in each of iridium, substrate and hydrogen concentrations.
The dependence of rate on the halogen followed the order I>Br>Cl, and quite remarkably traces of oxygen in the system enhance the hydrogenation rate considerably. Supplementary spectrophotometry studies have elucidated some of the equilibria involved and the mechanisms proposed show the importance of a solvent assisted dissociation step in making available a coordination site on the transition metal complex.
A detailed path for the catalytic hydrogenation is suggested. / Science, Faculty of / Chemistry, Department of / Graduate
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Synthesis of chiral ferrocenylphosphine complexes of rhodium (I) and their use as catalysts for homogeneous asymmetric hydrogenationYeh, Eshan January 1977 (has links)
The present work was directed toward the synthesis of a new chiral catalyst for asymmetric homogeneous hydrogenation. Efficient ways to synthesize the ferrocenylphosphine ligands (R,S)- and (S,R)-⍺-[2-diphenylphosphinoferrocenyl]ethyldimethylamine ((R,S)- and (S,R)-FcNP) and their cationic rhodium complexes [(diene)Rh(±)FcNP]⁺A⁻ were developed. Structural data for the ligand and models of its metal complex have been used to rationalize the stereochemical approach of the substrate to the metal complex, and hence predict the absolute configuration of the product.
The rate of catalytic hydrogenation is dependent on the substrate as is the optical yield of the product alkane. High optical yields are obtained when ⍺-acetamidocinnamlc acid is hydrogenated at 1 atm H₂ and 32°. / Science, Faculty of / Chemistry, Department of / Graduate
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