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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
111

The atomic weight of palladium ...

Kemmerer, George Irving. January 1908 (has links)
Thesis (Ph. D.)--University of Pennsylvania.
112

Synthese von ligandstabilisierten bimetallischen Palladium-Rhodium- und Platin-Rhodium-Nanoteilchen und deren Verwendung als Katalysatoren zur Wechselwirkung der Metalle bei bimetallischen, schalenförmigen Kolloiden /

Stahlhut, Rainer. January 2001 (has links) (PDF)
Essen, Universiẗat, Diss., 2001.
113

Selbstorganisierte Nanostrukturen Diffusion und Agglomeration von Adatomen auf der anisotropen Pd(110)-Oberfläche /

Filleböck, Georg. Unknown Date (has links)
Universiẗat, Diss., 1998--Konstanz. / Erscheinungsjahr auf der Haupttitelstelle: 1998. Gedr. Ausg. im Verl. UFO, Atelier für Gestaltung und Verl., Allensbach als: UFO-Dissertation ; Bd. 336.
114

Palladian gold mineralisation (ouro preto) in Brazil Gongo Soco, Itabira and Serra Pelada = Über das Vorkommen von Palladiumhaltigem Gold (ouro preto) in Brasilien /

Cabral, Alexandre Raphael. Unknown Date (has links) (PDF)
Techn. University, Diss., 2003--Clausthal.
115

Palladium (II)-catalyzed stereoselective formation of [alpha]-O-glycosides

Schuff, Brandon Patrick. January 2007 (has links) (PDF)
Thesis (M.S.)--Montana State University--Bozeman, 2007. / Typescript. Chairperson, Graduate Committee: Hien Nguyen. Includes bibliographical references.
116

Chiral nitrogen ligands in asymmetric catalysis

Moreau, Christelle January 2000 (has links)
No description available.
117

Aplicações analíticas de complexos mistos de haletos de paládio e platina com trifenilfosfina, - arsina, - estibina / Analytical applications of mixed complexes of palladium and platinum halides with triphenylphosphine, arsine, stibine

Sergio Massaro 17 March 1972 (has links)
1. É relatado estudo sistemático da extratibilidade de complexos mistos de metais de transição com haletos, pseudohaletos e trifenilfosfina, arsina, estibina, sob condições variadas, com diversos solventes, mostrando as tendências gerais de comportamento das espécies envolvidas. Dessa ampla abordagem derivam algumas possibilidades de aplicações analíticas que são desenvolvidas. 2. A presença de cianeto impede a formação e destrói alguns complexos de paládio do tipo acima referido, fato que conduziu à elaboração de uma prova de toque para este íon. Papel convenientemente preparado, contendo complexo de paládio, é descorado por HCN desprendido de amostras contendo cianeto, possibilitando a identificação de 0,3 µg de CN. Na presença de interferentes, algumas modificações de procedimento tornam o teste praticamente específico. 3. A partir de soluções aquosas contendo o ácido hacloroplatínico (IV), soluções benzênicas de trifenilestibina somente extraem o produto organometálico na presença de iodeto e não de brometo ou cloreto. As condições para uma extração seletiva e subsequente determinação espectrofotométrica de iodeto são indicadas, assim como as tolerâncias para outros íons estranhos. O método elaborado permite identificar iodeto na faixa de concentração de 6 - 24 ppm na diluição final, sendo a medida espectrofotométrica efetuada em 385 nm. 4. O complexo diazido-bis(trifenilfosfina)-paládio (II), em solução benzênica, reage com monóxido de carbono dando o isocianeto complexo correspondente, com mudança das características espectrais região do ultravioleta próximo. Com base nesta reação, mostra-se que possível a determinação espectrofotométrica de monóxido de carbono misturas gasosas com teores 700 - 3000 ppm. / Abstract not available.
118

Die bereiding en palladium-gekataliseerde reaksies van geselekteerde onversadigde suikers

Engelbrecht, Gerhardus Jacobus 29 May 2014 (has links)
M.Sc. (Chemistry) / Please refer to full text to view abstract
119

Synthesis and evaluation of ferrocenylpyrazolyl and ferrocenylpyrazolyl-phosphine palladium and nickel complexes as ethylene oligomerization catalysts

Van der Westhuizen, Arnoux 07 June 2012 (has links)
M.Sc. / Several bis[1-ferrocenyl(ethyl)pyrazolyl palladium dichloro (complexes 1 and 3) and palladium chloromethyl complexes (complexes 2 and 4) have been synthesized by the reactions of 1- ferrocenyl(ethyl)-1N-pyrazole and 1-ferrocenyl(ethyl)-1N-(3,5-dimethyl)pyrazole with [PdCl2(NCMe)2] and [PdClMe(cod)] respectively. Furthermore, a library of phosphorus^nitrogen (P^N) ferrocenyl(ethyl)-amine and -pyrazolyl ligands have been successfully synthesized using the well known Ugi amine (compound 5) as intermediate. 1- [2-{diphenylphosphino}ferrocenyl](ethyl)amine and 1-[{2-diphenylphosphino}ferrocenyl](ethyl)- pyrazolyl Ni(II) and Pd(II) complexes were synthesized by reacting 1-[2- {diphenylphosphino}ferrocenyl](ethyl)dimethylamine, 1-[2-{diphenylphosphino}ferrocenyl](ethyl)- 1N-pyrazole and 1-[2-{diphenylphosphino}ferrocenyl](ethyl)-1N-(3,5-dimethyl)pyrazole with [NiCl2•6H2O] (compounds 12 and 16), [NiBr2(DME)] (compounds 13, 17 and 19), [PdCl2(NCMe)2] (compounds 10, 14, and 18) and [PdClMe(cod)] (compounds 11 and 15), respectively. 1-[2- {Diphenylphosphino}ferrocenyl(ethyl)-1N-(3,5-dimethyl)pyrazole (compound 9) was synthesized by two distinct methodologies. In one method, 1-ferrocenyl(ethyl)dimethylamine was converted to 1-[2- {diphenylphosphino}ferrocenyl](ethyl)dimethylamine before it was subsequently reacted with 3,5- dimethylpyrazole to produce 1-[2-{diphenylphosphino}ferrocenyl(ethyl)-1N-(3,5-dimethyl)pyrazole. In the other method, 1-ferrocenyl(ethyl)-1N-(3,5-dimethyl)pyrazole was converted to 1-[2- {diphenylphosphino}ferrocenyl](ethyl)-1N-(3,5-dimethyl)pyrazole before the reaction with 3,5- dimethylpyrazole, producing 1-[2-{diphenylphosphino}ferrocenyl(ethyl)-1N-(3,5-dimethyl)pyrazole. These compounds synthesized via different methods as well as their palladium dichloro complexes show different structures in solution, but solid state structural analysis agrees on the same structure. The structural difference in solution is contributed to the high degree of flexibility at the stereogenic centre of the complex. The Ni(II) ferrocenyl phosphine complexes 12, 13, 16, 17 and 19 exist in equilibrium between diamagnetic square planar form and paramagnetic tetrahedral form. The tetrahedral geometry is xvi favoured over the square planar geometry, purely on steric grounds, but the square planar geometry occurs with d8 complexes because of the more favourable electronic situation of the complex. Activation of these P^N palladium and nickel ferrocenyl- amine and -pyrazolyl pre-catalysts 10, 12, 13, 14, 16, 17, 18a and 19 with EtAlCl2 results in the oligomerization of ethylene to C4 and C6 alkenes, followed by subsequent Friedel-Crafts alkylation of the toluene solvent. Moderate catalytic activities of up to 659 kg of alkylated toluene products.mol-1 Ni. h-1 were observed for catalyst 13 at 20 bar ethylene pressure. In general, the Ni(II) pre-catalysts were more active than the Pd(II) precatalyst.
120

Palladium catalysed hydroformylation of alpha-olefins

Ferreira, Alta 07 September 2012 (has links)
M.Sc. / The main objective of the research described in this dissertation, was the optimisation of the palladium catalysed hydroformylation of a-olefms. An evaluation of the efficiency of the palladium catalysed hydroformylation process required a comparison with the hydroformylation processes based on cobalt and rhodium. Variation of ligands (diphosphines of the size R2P(CH2)nPR2), solvents, acids, etc. had a dramatic effect on the products and the rate of the reaction. Trifluoroacetic acid was used to yield C-6 aldehydes from 1-pentene while trifluoromethanesulfonic acid yields C-11 ketones. Corresponding results were obtained with 1-octene as substrate. The length of the carbon bridge between the two phosphorous atoms has an optimum length of two in the case of alkylphosphine ligands, while an optimum length of three was found in the case of arylphosphine ligands. One disadvantage of the palladium catalysed hydroformylation reaction is that this reaction requires the use of bidentate phosphine ligands. These ligands are relatively expensive and also difficult to synthesise. The instability of the palladium complex and thus the precipitation of palladium were one of the major obstacles that had to be overcome. The use of additives not only increased the rate of hydroformylation but also increased catalyst stability, which in turn allowed an increase in the reaction temperature. This further increased the rate of the palladium catalysed hydroformylation reaction. These palladium catalysts were found to affect isomerisation of the a-olefin, but isomerisation was not a rate limiting process with respect to the hydroformylation reaction. Palladium catalysed isomerisation reactions occurred at a slower rate than the corresponding cobalt catalysed isomerisation process. However, with rhodium no isomerisation occurred. The comparison between cobalt, rhodium and palladium showed that rhodium is the best catalyst for the hydroformylation of a-olefins. The pressures and temperatures required for this process are much slower than that required for palladium and cobalt. The ligand used is triphenylphosphine, which is relatively inexpensive and non-toxic, in contrast with the more expensive ligands required for the cobalt and palladium hydroformylation processes. The use of palladium opens up the unique possibility of converting a-olefins into "dimeric" ketones, which show promise as precursors for the new class of geminidetergent

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