Alkyl aluminum oxides

Karl Ziegler describes the formation of alkyl aluminum oxides and the subsequent reaction of the primary produced dialkyl aluminum hydroxide [28]. It was also recognized that bis(diethylaluminum)oxide decomposes by disproportionation into triethyl-aluminum and a solid, non-volatile compound [29]. Bis(dimethylaluminum) oxide is mentioned in the hterature but not exactly described [30]. 

For this alcohol synthesis stoichiometric amounts of aluminum alkyls are required. Beside the wanted fatty alcohols high-purity aluminum oxide is formed. This aluminum oxide is of high value, e.g., for the production of catalysts and improves the economy of the Alfol process. 

The catalytic system used in the Pacol process is either platinum or platinum/ rhenium-doped aluminum oxide which is partially poisoned with tin or sulfur and alkalinized with an alkali base. The latter modification of the catalyst system hinders the formation of large quantities of diolefins and aromatics. The activities of the UOP in the area of catalyst development led to the documentation of 29 patents between 1970 and 1987 (Table 6). Contact DeH-5, used between 1970 and 1982, already produced good results. The reaction product consisted of about 90% /z-monoolefins. On account of the not inconsiderable content of byproducts (4% diolefins and 3% aromatics) and the relatively short lifetime, the economics of the contact had to be improved. Each diolefin molecule binds in the alkylation two benzene molecules to form di-phenylalkanes or rearranges with the benzene to indane and tetralin derivatives the aromatics, formed during the dehydrogenation, also rearrange to form undesirable byproducts. 

Alfol Also called the Conoco process and the Muhlheim process. The same name is used for the products as well. A process for making linear primary alcohols, from C2 to C28, from ethylene. The ethylene is reacted with triethyl aluminum, yielding higher alkyl aluminums These are oxidized with atmospheric oxygen under mild conditions to aluminum alkoxides, which are then hydrolyzed by water to the corresponding alcohols ... 

Aluminum alkyl, 27 236 Aluminum chloride, 27 250 Aluminum chloride-1,3-dialkylimidazolium chloride catalyst system, 42 495—496 Aluminum oxide, 27 268, 269, 32 57-58, 34 195-197... 

A number of reagents containing oxide components are used in zeolite manufacture [19]. Silica is provided by addihon of sodium or other alkali silicate solutions, precipitated, colloidal, or fumed silica, or tetraalkylorthosihcate (alkyl = methyl, ethyl) and certain mineral silicates such as clays and kaolin. Alumina is provided as sodium aluminate, aluminum sulfate soluhon, hydrous aluminum oxides such as pseudo boehmite, aluminum nitrate, or aluminum alkoxides. Additional alkali is added as hydroxide or as halide salts, while organic amines and/or... 

Quite recently it was shown that phosphonic esters, trimethylsilyl [124, 143] and alkyl esters [124,143, 145] could also be used to modify the surface of titanium or aluminum oxide in organic solvents at moderate temperatures. Unlike Si-O-C bonds, P-O-C bonds are not easily hydrolyzed, and their cleavage on an oxide surface was unexpected. Most probably, coordination of the phosphoryl oxygen to the surface assists the condensation by increasing the electrophilicity of the P atom, thus facilitating the condensation of P-0-R groups with surface hydroxyls (Scheme 7) [124]. The chemisorption of... 

Allyl glycldyl ether Allyl propyl disulfide alpha-Alumlna Aluminum alkyls Aluminum metal and oxide Aluminum pyro powders Aluminum soluble salts Aluminum welding fumes 4-Aminodlphenyl 2-Aminopyrldlne Amilrole Ammonia... 

Guidelines a. Air ACGIH TLV TWA Aluminum metal dust pyro powders, as Al welding fumes, as Al soluble salts, as Al alkyls (not otherwise classified) Aluminum oxide 10 mg/m3 5 mg/m3 5 mg/m3 2 mg/m3 2 mg/m3 10 mg/m3 ACGIH 1996... 

A supported catalyst for ethylene polymerization which requires no alkyl aluminum for activation was first claimed by the Phillips Petroleum Company (32). It consists of chromium oxide on silica, reduced with hydrogen. Krauss and Stach (93) showed that the active sites are Cr(II) centers. The presence of solvent, or even aluminum alkyls, diminishes... 

Out of batch box 2 triethylaluminum (in the form of 10-12% isooctane or petrol solution) is pumped with batching pump 4 into the top part of absorber 3. The middle of the absorber is filled under the pressure of 3-4 MPa with ethylene, which has been dried and purified in the system of subsequent towers with active aluminum oxide and active coal. In the absorber the triethylaluminum solution is presaturated with ethylene to ensure exact operation of the batching equipment. The triethylalumi-num ethylene mole ratio can be from 1 9 to 1 25 depending on the desired distribution of alkyl groups in aluminumtrialkyls. 

Both di- and trimerization of butadiene with soluble nickel catalysts are well-established homogeneous catalytic reactions. The precatalyst having nickel in the zero oxidation state may be generated in many ways. Reduction of a Ni2+ salt or a coordination complex such as Ni(acac)2 (acac = acetylacetonate) with alkyl aluminum reagent in the presence of butadiene and a suitable tertiary phosphine is the preferred method. The nature of the phosphine ligand plays an important role in determining both the activity and selectivity of the catalytic... 

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