Nickel complex tellurium

Catalysts. In industrial practice the composition of catalysts are usuaUy very complex. Tellurium is used in catalysts as a promoter or stmctural component (84). The catalysts are used to promote such diverse reactions as oxidation, ammoxidation, hydrogenation, dehydrogenation, halogenation, dehalogenation, and phenol condensation (85—87). Tellurium is added as a passivation promoter to nickel, iron, and vanadium catalysts. A cerium teUurium molybdate catalyst has successfliUy been used in a commercial operation for the ammoxidation of propylene to acrylonitrile (88). 

Alkyl phenyl telluriums and diaryl telluriums react with Grignard reagents in THF or diethyl ether in the presence of catalytic amounts of nickel- or cobalt-phosphane complexes. Tellurium is precipitated. The organic groups combine to form in most cases all three possible coupling products in ratios determined by reaction conditions . The reaction of ( Z,)-phenylethenyl phenyl tellurium and phenyl magnesium bromide formed almost exclusively ( Zj-stilbene in quantitative yield. ( ZJ-Ethoxycarbonylethenyl phenyl tellurium and phenyl magnesium bromide reacted differently ( Fj-ethoxycarbonyl-(phenyl)-ethene and diphenyl tellurium were produced. Tellurium was not formed. ... 

Early catalysts for acrolein synthesis were based on cuprous oxide and other heavy metal oxides deposited on inert siHca or alumina supports (39). Later, catalysts more selective for the oxidation of propylene to acrolein and acrolein to acryHc acid were prepared from bismuth, cobalt, kon, nickel, tin salts, and molybdic, molybdic phosphoric, and molybdic siHcic acids. Preferred second-stage catalysts generally are complex oxides containing molybdenum and vanadium. Other components, such as tungsten, copper, tellurium, and arsenic oxides, have been incorporated to increase low temperature activity and productivity (39,45,46). 

Dithiobenzoic acid metal complexes, 2, 646 colours, 2, 646 Dithiobiuret metal complexes, 2, 640 Dithiocarbamates chelating resins mineral processing, 6,826 Dithiocarbamic acid metal complexes, 2,585 amine exchange, 1,428 photographic emulsions, 6,98 nickel poisoning, 6,768 tellurium(Il) complexes photothermography, 6,121 Dithiocarbazic acid metal complexes, 2,803 Dithiocarbimic acid metal complexes, 2,588 Dithiocarbimic acid, cyano-metal complexes, 2,808 Dithiocarboxylic acids metal complexes, 2,646 Dithiodiacetic acid metal complexes, 2, 806 Dithiodiketones... 

Dimethyl-I,l -biphenyl has been prepared by a wide variety of procedures, but few of these are of any practical synthetic utility Classical radical biarjl syntheses such as the Gomberg reaction or the thermal decomposition of diaroyl peroxides give complex mixtures of products m which 4,4 dimethyl-l.l -biphenyl is a minor constituent A radical process maj also be involved in the formation of 4,4 dimethyl-1, l -biphenyl (13%) by treatment of 4-bromotoluene with hydrazine hydrate 5 4,4 -Dimethyl-l,l -biphenyl has been obtained in moderate to good yield (68-89%) by treatment of either dichlorobis(4-methyl phenyl)tellurium or l,l -tellurobis(4-methylbenzene) with degassed Raney nickel in 2 methoxyethyl ether 6... 

The great structural diversity of coordination patterns and supramolecular self-assembly has been analyzed in detail for nickel(II), zinc(II), mercury(II), and tellurium (II),246fe(xanthato) complexes. 

The structural chemistry of some metal dithiocarbamates, i.e. systematics, coordination modes, crystal packing, and supramolecular self-assembly patterns of nickel, zinc, cadmium, mercury,363 organotin,364 and tellurium,365 366 complexes has been thoroughly analyzed and discussed in detail. Supramolecular self-assembly frequently occurs in non-transition heavier soft metal dithiocarbamates. Thus, lead(II),367 bismuth(III)368 zinc,369 cadmium,370 and (organo)mercury371 dithiocarbamates are associated through M- S secondary bonds, to form either dimeric supermolecules or chain-like supramolecular arrays. The arsenic(III)372 and antimony(III)373 dithiocarbamates are... 

Nickel(II) Complexes with Sulfur-, Selenium-and Tellurium[Pg.2]

In the following section we will report on the most recent developments of nickel-sulfur (as well as selenium and tellurium) coordination chemistry, but selected examples of the first reported complexes with classical sulfur-containing ligands which have been extensively reported in the aforementioned article reviews will be also included. 

Grignard reagents remove tellurium from the tellurophene ring in refluxing benzene in the presence of nickel-phosphine complexes. ... 

Among the recent reports on metal xanthate chemistry the following are mentioned, dealing with the structural diversity of nickel(II),213 zinc(II),214 mercury(II), 15 and tellurium(II) bis (xanthate) complexes,216 based upon different coordination patterns and supramolecular self-assembly. 

The binary phase diagram nickel/tellurium as summarised by Lee and Nash [90LEE/NAS] shows a complex behaviour with six intermetallic solid phases. This diagram is essentially based on a seminal paper authored by Klepp and Komarek [72KLE/KOM]. The phases Pi, P2, P[ andNiTe2- t(cr) have variable stoichiometry. 

Nickel(II) Complexes with Sulflir-, Selenium- and Tellurium-containing L ands 50.5.6.1 Introduction... 

---