Rhodium zirconium

Conversion of monocyclic and polycyclic vinylcyclopropanes with low-valent transition-metal complexes, (e.g. iron, rhodium, zirconium, cobalt, nickel, palladium) mainly leads to ring opening and rearrangement products. A typical reaction pathway of vinylcyclopropanes with transition-metal complexes leads to f/Calkyl-j/ -allyl complexes, which as homodiene complexes exhibit interesting reaction patterns (e.g. carbonylation) leading to organic products. ... 

Stream number Ruthenium-rhodium Zirconium-niobium Total fission products... 

Three-way catalysts used in exhaust-gas catalytic converters of automobiles contain platinum, palladium, rhodium, zirconium, and cerium. Oki et al. have developed a method which concentrates these metals by means of a two-step crushing procedure (Kim et al., 2010 Oki et al. 2010). The process makes it possible to increase concentration of rare-earth metals by a factor of five by first demolishing the honeycomb structure, and then peeling off the surface. To date, no process leading to recovery of individual rare-earth metals has been described. 

The corrosion behaviour of amorphous alloys has received particular attention since the extraordinarily high corrosion resistance of amorphous iron-chromium-metalloid alloys was reported. The majority of amorphous ferrous alloys contain large amounts of metalloids. The corrosion rate of amorphous iron-metalloid alloys decreases with the addition of most second metallic elements such as titanium, zirconium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, cobalt, nickel, copper, ruthenium, rhodium, palladium, iridium and platinum . The addition of chromium is particularly effective. For instance amorphous Fe-8Cr-13P-7C alloy passivates spontaneously even in 2 N HCl at ambient temperature ". (The number denoting the concentration of an alloy element in the amorphous alloy formulae is the atomic percent unless otherwise stated.)... 

Z 1 Niobium 1 Nitrate 1 Osmium 73 a. I Perchlorate Phenols u a o Platinum o 0. 1 5 u 1 Rhodium 1 Rubidium Ruthenium Scandium 1 Selenium Silver I Sodium 1 Strontium 1 Sulphate Sulphides, organic Sulphur dioxide 1 Tantalum 1 Tellurium 1 Thallium Thorium e H 1 Titanium a u ab a 1- I Uranium 1 Vanadium 1 Yttrium 1 Zinc Zirconium... 

Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon... 

The reductive cyclization of non-conjugated diynes is readily accomplished by treatment of the acetylenic substrate with stoichiometric amounts of low-valent titanium52 523 and zirconium complexes.53 533 Hence, it is interesting to note that while early transition metal complexes figure prominently as mediators of diyne reductive cyclization, to date, all catalyzed variants of this transformation employ late transition metal complexes based on nickel, palladium, platinum, and rhodium. Nevertheless, catalytic diyne reductive cyclization has received considerable attention and is a topic featured in several review articles. ... 

In this chapter, we will focus on the rhodium-catalyzed hydrogenation of functionalized ketones and the development of chiral phosphorous ligands for this process. Although there are other chiral phosphorous ligands which are effective for ruthenium-, iridium-, platinum-, titanium-, zirconium-, and palladium-catalyzed hydrogenation, they will not be discussed here. For details of these chemistries, the reader should refer to other chapters of this book. 

Scheme 4.S8. Zirconium- and rhodium-catalyzed hydroborations of alkenes and alkynes with pinacolborane.

Zirconium oxide is of interest as a catalyst, as a support for other catalysts and as a diffusion barrier. In the latter application a thin layer of Zr02 prevents the dissolution of rhodium in alumina supports under severe oxidative conditions [32], Here it is essential to apply Zr02 on the support at the highest possible... 

Another study on the preparation of supported oxides illustrates how SIMS can be used to follow the decomposition of catalyst precursors during calcination. We discuss the formation of zirconium dioxide from zirconium ethoxide on a silica support [15], Zr02 is catalytically active for a number of reactions such as isosynthesis, methanol synthesis, and catalytic cracking, but is also of considerable interest as a barrier against diffusion of catalytically active metals such as rhodium or cobalt into alumina supports at elevated temperatures. 

Calcium, 3922 Cerium, 3961 Chromium, 4222 Cobalt, 4199 Europium, 4292 Hafnium, 4599 Iridium, 4643 Iron, 4388 Lead, 4882 Manganese, 4700 Nickel, 4820 Palladium, 4885 Platinum, 4887 Plutonium, 4888 Rhodium, 4892 Rubidium, 4889 Strontium, 4913 Tantalum, 4914 Technetium, 4915 Thorium, 4917 Titanium, 4919 Tungsten, 4925 Uranium, 4923 Vanadium, 4924 Zinc, 4927 Zirconium, 4928... 

Given the importance of chiral amines to synthetic chemistry as well as other fields asymmetric hydrogenation of imines has attracted wide interest but limited success compared to C=C and C=0 bond reduction. The first asymmetric hydrogenation of imines was carried out in the seventies with mthenium- and rhodium-based catalysts, followed later by titanium and zirconium systems [82]. Buchwald found that... 

Rubidium Strontium Yttrium Zirconium Niobium Moiybdenurr Technetium Ruthenium Rhodium... 

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