Zinc and Cadmium Compounds

Second order non-linear optical properties have been reported for a variety of TTF donor-acceptor compounds <02T7463> and the palladium complex 84 is a room-temperature semiconductor <02CL936>. Preparation of the zinc and cadmium compounds 85 has been reported <02CC1474> and aromatic fused TTFs such as 86 form thin films with useful electrical properties <02JAP265466>. A ferromagnetic interaction occurs in the salt of a TTF... 

DIVALENT ZINC AND CADMIUM COMPOUNDS 15-7 Aqua Ions, Oxides, and Hydroxides... 

Analysis of X-ray diffraction patterns of the precipitates resulting from the addition of salts of the four metals to GSL North Arm brine showed that both copper and lead precipitated in the basic carbonate form. Zinc and cadmium compounds were not found in these X-ray diffraction traces, which may be due to these compounds comprising less than five percent of the solid material analyzed. 

A number of stannyl-zinc and -cadmium compounds have been prepared by reaction of a tin-alkali metal compound with a zinc or cadmium halide, or a tin hydride with an alkyl-zinc or -cadmium compound. The coordination of a ligand such as a triphenyl-phosphine, TMEDA, or bipyridyl, or a solvating solvent such as DME, both enhances the nucleophilicity of the alkyl group in the alkylmetallic compounds and stabilises the stannylmetallic product. Thus triphenyltin hydride reacts with diethylzinc or diethylcad-mium in pentane or benzene with separation of metallic zinc or cadmium, but with a preformed complex, or in a coordinating solvent, the distannylmetallic compound is formed (e.g. equation 19-32). 

Sapozhnikov and Markovskii measured at 298.15 K the enthalpy of dissolution of a number of zinc, cadmium, and mercury selenites in mineral aeid in a calorimeter. Sulphuric acid (aq, 1 50) was used for the zinc and cadmium compounds, while hydrochloric acid (aq, 1 35) was used for the mercury salts. The experimental details are few and... 

Organozinc compounds are historically important39 since they were the first organometallic compounds to be prepared their discovery by Frank-land in 1849 played a decisive part in the development of modern ideas of chemical bonding. The zinc and cadmium compounds are also of interest since their mild reactivities toward certain organic functional groups give them unique synthetic potentialities. 

Both zinc and cadmium compounds react readily with compounds containing active hydrogen, such as alcohols ... 

Bis- and tris(trimethylsilyl)methyllithium can be obtained by reacting RLi with the appropriately substituted methane [113] Bis(trimethylsilylmethyl) derivatives of zinc [114] cadmium [115] and mercury [112] are all volatile liquids. The zinc and cadmium compounds are readily hydrolysed and oxidized, unlike the mercury derivative. 

Metal selenolates of the type M(SeAr)2 (M = Zn, Cd, Hg) are usually insoluble, polymeric compounds. Intramolecular Se N coordination has been employed to stabilize monomeric mercury selenolates, e.g., 15.27, but this approach was not successful for the zinc and cadmium derivatives. ... 

Zinc and cadmium have an oxidation number of +2 in all their compounds. Zinc is an essential element for human health. It is present in many enzymes and plays a role in the expression of DNA and in growth. Zinc is toxic only in very-high amounts. However, cadmium is a deadly poison that disrupts metabolism by-substituting for other essential metals in the body such as zinc and calcium, leading to soft bones and to kidney and lung disorders. 

D. A. Shirley, The Synthesis of Ketones from Acidhalides and Organometallic Compounds of Magnesium, Zinc and Cadmium, Organic Rcaktions, Vol. VIII, 28 (1954). 

Formation of the Group-IB or -IIB-Group-IB or -MB Metal Bonds 8.2.3. In Univalent Compounds of Zinc and Cadmium... 

Mass effects due to some ions in salts. It is generally observed that there is a greater instability amongst compounds containing heavy atoms compared with elements in the first periods of the periodic tabie.This can be observed by analysing enthalpies of formation of ammonia, phosphine, arsine and stibine (see previous table for the last three). In the same way, it is easier to handle sodium azide than lead azide, which is a primary explosive for detonators. It is exactly the same with the relatively highly stable zinc and cadmium thiocyanates and the much less stable mercury thiocyanate. 

Copper (II) sulphide is like any other sulphide, ie very reactive vis- -vis oxidants. Therefore detonations occur during mixtures between this compound and magnesium, zinc and cadmium chlorates. 

Coprecipitation is a partitioning process whereby toxic heavy metals precipitate from the aqueous phase even if the equilibrium solubility has not been exceeded. This process occurs when heavy metals are incorporated into the structure of silicon, aluminum, and iron oxides when these latter compounds precipitate out of solution. Iron hydroxide collects more toxic heavy metals (chromium, nickel, arsenic, selenium, cadmium, and thorium) during precipitation than aluminum hydroxide.38 Coprecipitation is considered to effectively remove trace amounts of lead and chromium from solution in injected wastes at New Johnsonville, Tennessee.39 Coprecipitation with carbonate minerals may be an important mechanism for dealing with cobalt, lead, zinc, and cadmium. 

The reaction is conducted in the melt, in the presence of carbon dioxide under pressure, catalyzed by zinc or cadmium compounds. Invented by B. Raecke at Henkel, Germany. Improved variations of this process, known as Henkel I and Henkel II, were operated by several other companies, but by 1975 had been abandoned in favor of various other methods of oxidizing /j-xylcne. 

In recent years new types of carbanions have been prepared which are paired with different metals and this has found the basis for the preparation of many novel organometallic compounds. Some of these metals include group IA, IIA metals besides aluminium, zinc and cadmium. 

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