Palladium

Summary

Palladium is a chemical element with the symbol Pd and atomic number 46. It is a rare and lustrous silvery-white metal discovered in 1803 by the English chemist William Hyde Wollaston. He named it after the asteroid Pallas, which was itself named after the epithet of the Greek goddess Athena, acquired by her when she slew Pallas. Palladium, platinum, rhodium, ruthenium, iridium and osmium form a group of elements referred to as the platinum group metals (PGMs). They have similar chemical properties, but palladium has the lowest melting point and is the least dense of them. More than half the supply of palladium and its congener platinum is used in catalytic converters, which convert as much as 90% of the harmful gases in automobile exhaust (hydrocarbons, carbon monoxide, and nitrogen dioxide) into nontoxic substances (nitrogen, carbon dioxide and water vapor). Palladium is also used in electronics, dentistry, medicine, hydrogen purification, chemical applications, groundwater treatmen

Official source

https://en.wikipedia.org/wiki/Palladium

About this result

This page is automatically generated and may contain information that is not correct, complete, up-to-date, or relevant to your search query. The same applies to every other page on this website. Please make sure to verify the information with EPFL's official sources.

Related publications (60)

Related publications

Related people (8)

, , , , , , ,

Related people

Related units (6)

Related units

Related concepts (116)

Related concepts

Related courses (13)

Related courses

Related lectures (19)

Related lectures

Selective hydrogenation of an a,b-unsaturated aldehyde using palladium catalysts

EPFL2002

New Synthetic Applications of Water Acetate Pd/TPPTS Catalyst Generated in situ. Evidence for true Pd(0) Valent Species Intermediate

Christian Amatore

Studies on the sp-sp intermolecular coupling reactions with the palladium water-soluble catalyst prepared in situ from palladium(II) acetate and sulfonated triphenylphosphine P(C6H4-m-SO3Na)(3) (TPPTS) in a homogeneous acetonitrile-water system, without Cu(I) promotor, afford diynes with moderate yields (45-65%). Under the same conditions, the sp(2)-sp coupling of 2-iodophenols or 2-iodoanilines and terminal alkynes followed by intramolecular cyclization gives indolic and furanic products in good yields (60-99%). Under these aqueous conditions, an efficient and short synthesis of eutypine illustrated the synthetic potentiality of the coupling. Furthermore, through a series of kinetic and P-31 NMR experiments, we have demonstrated that a mixture of Pd(OAc)(2) and TPPTS affords spontaneously a palladium(0) complex, through formation of bivalent complex Pd(OAc)(2)-(TPPTS)(2). A detailed mechanism of the reaction has been investigated thoroughly and the pertinent rate constants measured. The resulting palladium(0) complex reacts with phenyl iodide via an oxidative addition. This complex is considerably less reactive than the corresponding complex generated from PPh(3), probably due to steric effects.

1995

Chemosensors based on indicator displacement were developed for the optical detection of different analytes in aqueous solution. The sensing of carbohydrates, including glucose, in aqueous solution at pH 7.4 was achieved by a fluorescent indicator displacement assay (IDA) based on a palladium complex. The assay is easy to perform as it just requires mixing of a commercially available dye and a simple Pd complex. The sensitivity of the assay is similar to what is typically found for boronic acid-based systems, but its selectivity profile towards different carbohydrates is quite distinct. Furthermore the same complex was employed for the successful differentiation of various diols. A palladium-based sensor is a novelty as almost all carbohydrate sensors exclusively utilize boronic acids as binding site. Various palladium complexes were evaluated and the usability for carbohydrate sensing was found to be strongly dependent on the ligands. Ruthenium-arene complexes are known to have potent anticancer properties. There is an interest in a quick and simple method to give information about the stability towards ligand exchange of these complexes in aqueous solutions. Indicator displacement assays, which can give information about the binding strength of different ligands to a ruthenium-arene complex, were investigated in water at pH 7.4. Various biomolecules (different amino acids, maltol etc.) could be differentiated by a colorimetric (naked eye) IDA. Additionally, a correlation between the binding strength of the bidentate ligand and the amount of indicator displaced was found. Matrix metalloproteinase (MMPs) are endoproteinases and their dysfunction can result in various health problems (e.g. arthritis). In order to provide a quick and simple tool for the evaluation of new MMP inhibitors, colorimetric IDAs were developed. For calibration of the system, MMP inhibitors were synthesized and their IC50 values for different MMP isoforms determined. Although the new MMP inhibitors have very similar structures a differentiation by an indicator displacement array was achieved. The IC50 values were, with a couple exceptions, rather high and similar. None of the new MMP inhibitors exhibited specific inhibition of one of the studied MMP isoforms.

EPFL2012