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Binary structures cobalt

Because Ni(CO)4 is volatile (b.p. 43 °C) and cobalt will not react under these conditions, this process afforded a method for separating Ni from Co by the process now known as the Mond process. Although there are many complexes known that contain both carbonyl and other ligands (mixed carbonyl complexes), the number containing only a metal and carbonyl ligands is small. They are known as binary metal carbonyls, and they are listed in Table 21.1. The structures of most of these compounds are shown later in Figures 21.1 through 21.3. [Pg.740]

A variety of cobalt xanthate structures are available in the literature, including four binary xanthates and a large range of phosphine adducts. By contrast, only one rhodium structure is known and no structure is yet available containing iridium. [Pg.162]

In addition to the binary catalysts from transition metal compounds and metal alkyls there 2ire an increasing number which are clearly of the same general type but which have very different structures. Several of these are crystalline in character, and have been subjected to an activation process which gives rise to lattice defects and catalytic activity. Thus, nickel and cobalt chlorides, which untreated are not catalysts, lose chlorine on irradiation and become active for the polymerization of butadiene to high cis 1,4-polymer [59]. Titanium dichloride, likewise not a catalyst, is transformed into an active catalyst (the activity of which is proportional to the Ti content) for the polymerization of ethylene [60]. In these the active sites evidently react with monomer to form organo-transition metal compounds which coordinate further monomer and initiate polymerization. [Pg.145]

A special type of catalyst which is typified by Raney Nickel is prepared by leaching out one component from a binary alloy leaving a skeletal structure of the desired catalyst. Raney Nickel itself is made by leaching out aluminium from an aluminium-nickel alloy with sodium hydroxide. Cobalt and iron catalysts have also been prepared in this manner. [Pg.221]

Another type of activation of aluminum alkyl was found in the asymmetric-selective polymerization of epichlorohydrin (ECH) with an optically active cobalt-salen type complex [Co (II)]. The structure of the salen-type cobalt complex was shown previously (13, 14). In a benzene solution of the binary system consisting of [Co (II)] and AlEt, no evolution of ethane or ethylene was observed at room temperature. The NMR signals of the methyl protons for AlEt shifted down field on mixing with [Co (II)]. These observations together with a circular dichroism study indicated that AlEt and [Co (II)] formed a molecular complex in benzene, none of Al-Et bonds being cleaved by this complexation. [Pg.28]

Solvent Structure. There has been some discussion of the importance of solvent structure in kinetics, for example in connection with aquation of cobalt(m) complexes in binary aqueous mixtures. There are difficulties in squaring the kinetic parameters for dimethylformamide and for dimethyl sulphoxide exchange at iron(u) with Bennetto and Caldin s model of solvent structural effects, but this model proved useful in discussion of the aquation of [Co(NH3)s(DMSO)] + in binary aqueous mixtures. Bulky hydrophobic groups in solvent molecules have an effect on solvent structure which is reflected in the kinetics of complex formation. - For dissociative solvent exchange at some M + ions, activation enthalpies appear to be determined by the solvation enthalpy of the metal ion and the solvent structure as manifested in its enthalpy of vaporization. In the reaction of Ni + with malonate, the range of solvent variation of activation parameters is comparable with their likely errors, preventing the authors from discussing their results in terms of Bennetto and Caldin s theories. ... [Pg.283]


See other pages where Binary structures cobalt is mentioned: [Pg.164]    [Pg.52]    [Pg.341]    [Pg.162]    [Pg.147]    [Pg.91]    [Pg.392]    [Pg.1558]    [Pg.274]    [Pg.163]    [Pg.494]    [Pg.437]    [Pg.484]    [Pg.104]    [Pg.712]    [Pg.150]    [Pg.1557]    [Pg.235]    [Pg.197]    [Pg.12]    [Pg.236]    [Pg.200]    [Pg.279]    [Pg.819]    [Pg.9]    [Pg.216]    [Pg.629]    [Pg.22]    [Pg.35]    [Pg.556]    [Pg.281]    [Pg.491]    [Pg.432]    [Pg.132]    [Pg.280]    [Pg.104]    [Pg.36]    [Pg.316]   
See also in sourсe #XX -- [ Pg.162 , Pg.163 , Pg.164 , Pg.165 ]




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Binary structures

Cobalt structure

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