METALLOORGANICS

Metalloorganic compounds of zinc, cadmium, and lithium can be added, just as the Grignard compounds, to the NN double bond of diazirines. ... 

Aivazyan FN, Matkovsky PE, Ponomarenko AT, Pavlii VG, Shamsullin IF, Kolesnikov YN, Enikolopyan NS (1983) In Complex metalloorganic catalysts of elefin polymerization, Chemo-golovka, p 73 (in Russian)... 

The new phenomenon discovered in these experiments consists in different chemical activity revealed by one and the same kind of adsorbed particles in contact with one and the same kind of molecules of the medium, but at different nature of the interface either interface of a solid (ZnO film) with a polar liquid or interface of the solid with vapours of the polar liquid. This difference is caused by the fact that in the case of contact of the film with an adsorbed layer (oxygen, alkyl radicals) with a polar liquid, the solvated ion-radicals O2 chemically interact with molecules of the solvent (see Chapter 3, Section 3.4). In the case where alkyl radicals are adsorbed on ZnO film, one can assume, by analogy with the case of adsorbed oxygen, that in the process of adsorption on ZnO, simple alkyl radicals from metalloorganic complexes of the type... 

CH3 -Zn with superstoichiometric (defect) zinc atoms (Zn -impurity centres of conductivity). The larger is the electric positivity of the metal in these complexes, the larger is the ionicity of the carbon-metal bond, carbon being at the negative end of the dipole. Thus, in the case of C - K bond, ionicity amounts to 51%, whereas for C - Mg and C - Zn bonds ionicity amounts to 35% and 18%, respectively [55]. Consequently, metalloorganic compounds are characterized by only partially covalent metal-carbon bonds (except for mercury compounds). 

Various techniques of thin film deposition, including CVD (also abbreviated as MOCVD, metalloorganic chemical-vapor deposition) have been under intensive development for the. r-block elements, and particularly the alkaline earth metals, since the late 1980s. - The lability of the Cp rings of 49 has also made it a useful source of the... 

The use of metalloorganic precursors for depositing inorganic electronic materials, encompassing the deposition of borides from metallaboranes or related complexes.2... 

One-electron reduction of metalloorganic complexes or coordination between a metal and an anion-radical ligand may expand an electron shell of the central metal atom. Sometimes, anion-radical metallocomplexes contrast in this regard with the cation-radical ones. Thus, the same metal-loporphyrins form cation-radicals with charges and unpaired electrons on ligands (Shinomura et al. 1981) and anion-radicals with charges and unpaired electrons on metals (Lexa et al. 1989). 

A special case is when the electrochem-ically active components are attached to the metal or carbon (electrode) surface in the form of mono- or multilayers, for example, oxides, hydroxides, insoluble salts, metalloorganic compounds, transition-metal hexacyanides, clays, zeolites containing polyoxianions or cations, intercalative systems. The submonolayers of adatoms formed by underpotential deposition are neglected, since in this case, the peak potentials are determined by the substrate-adatom interactions (compound formation). From the ideal surface cyclic voltammetric responses, E° can also be calculated as... 

Enzymes, like other proteins, have molecular weights ranging from about 12,000 to more than 1 million. Some enzymes require no chemical groups for activity other than their amino acid residues. Others require an additional chemical component called a cofactor—either one or more inorganic ions, such as Fe2+, Mg2+, Mn2+, or Zn2+ (Table 6-1), or a complex organic or metalloorganic molecule called a coenzyme (Table 6-2). Some enzymes require both a coenzyme... 

As observed by D. Johnson and J. Stiegler, "Polymer-precursor routes lor fabricating ceramics offer one potential means or producing reliable, cost-effective ceramics. Pyrolysis of polymeric metalloorganic compounds can be used to produce a wide variety of ceramic materials." Silicon carbide and silicon oxycarbide fibers have been produced and sol gel methods have been used In prepare line oxide ceramic powders, such as spherical alumina, as well as porous and fully dense monolithic forms. 

To improve the thermal stability of PVC, it is common to add stabilizers, generally metalloorganic compounds, in concentrations of 1-5 parts per 100 parts of PVC. Although the cis-1,4-polybutadiene grafted PVC, in the absence of an added stabilizer, yielded essentially colorless or only faintly discolored films, completely colorless films were obtained when the conventional stabilizers were added in concentrations of 0.1-0.3 parts per 100 parts of modified PVC. Organotin stabilizers were not necessary and, in some cases, actually resulted in greater color development than when they were absent. 

Ionic liquids (continued) for Heck coupling, 1, 870 for homogeneous-multi-phase catalysis, 1, 856 for hydroformylations, 11, 450 for hydrogenations, 1, 857 for kinetic study monitoring, 1, 517 metalloorganic ILs, 1, 853 and molten salts, 1, 848... 

Metallomesogens (continued) examples, 12, 273 imine complexes, 12, 254 pyrimidine complexes, 12, 270 overview, 12, 195-293 via palladacycles, 8, 288 thermotropic liquid crystals, 12, 197 Metalloorganic chemical-vapor deposition, for semiconductor growth, 12, 8... 

Metalloorganic liquids, characteristics, 1, 853 Metallopolymers, with n-coordinated metals, 12, 311 Metallosilanes, preparation methods, 3, 521 Metallostannation, in tin-carbon bond formation, 3, 817 Metal-metal bonds... 

Kochetkov continued as lecture assistant until 1951, combining this work with research on metalloorganic chemistry in Nesmeyanov s laboratory. He studied organo-mercury compounds, in particular their synthesis by the addition of mercuric chloride to acetylenes. In 1948 Nikolay wrote a thesis and received the Ph.D. degree in chemistry. 

Historically, the first metalloorganic method for the synthesis of organolead compounds was based on the use of zinc dialkyls. It was not surprising that the method was first... 

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