Ethylaluminum Sesquichloride

An obvious method to investigate the formation and the nature of the catalytically active nickel species is to study the nature of products formed in the reaction of complexes such as 3 or 4 with substrate olefins. This has been investigated in some detail in the case of the catalytic dimerization of cyclooctene to 1-cyclooctylcyclooctene (17) and dicy-clooctylidene (18) [Eq. (4)] using as catalyst 7r-allylnickel acetylacetonate (11) or 7r-allylnickel bromide (1) activated by ethylaluminum sesquihalide or aluminum bromide (4). In a typical experiment, 11 in chlorobenzene was activated with excess ethylaluminum sesquichloride cyclooctene was then added at 0°C and the catalytic reaction followed by removing... 

Diisobutylaluminum hydride Dimethyldichlorosilane Diphenyldichlorosilane Dipropylaluminum hydride Ethylaluminum dichloride Ethylaluminum sesquichloride Ethyldichloro silane Ethyltrichlorosilane Fluorine... 

Ethylaluminum sesquichloride induces the alkylation of alkenes with isopropyl chloroformate.453 Terminal alkenes [Eq. (5.79)] and cycloalkenes react in the presence of Et3SiH ... 

Although the infrared spectra of the equimolar styrene-methyl acrylate or methyl methacrylate copolymers prepared in the presence of ethylaluminum sesquichloride and the equimolar copolymers prepared with azobisisobutyronitrile are very similar, the nuclear magnetic resonance spectra of the former are distinctly different from the latter and... 

Childers (5) found that a cobalt-catalyzed polymerization terminated with C14 labelled alcohol resulted in activity in the polymer, whereas H3 hydroxyl labelled alcohol gave inactive polymer. He deduced, therefore, that the mechanism was cationic. The organometal compound used in this catalyst was ethylaluminum sesquichloride, and his observations have been confirmed (26). We carried out virtually the same experiment as Childers except that AlEt2Cl was used instead of AFEtsCh with the opposite conclusion—namely, the growth was anionic (8). 

SYNS ETHYLALUMINUM SESQUICHLORIDE SESQUIETHYLALUMINUM CHLORIDE TRICHLOROTRIETHYLDIALUMINIUM TRICHLOROTRlETHYLDIALU NUM TRIETHYE ALUMINUM SESQUICHLORIDE TRIETHYL-TRICHLORODIALUMNUM... 

More than 20 aluminum alkyls are presently offered in the merchant market. As of this writing, most of the high-volume products are priced between about 5 and 10 per pound. Exceptions include trimethylaluminum (which is produced by a costly multi-step process (13)) and diethylaluminum iodide (which requires expensive iodine). Triethylaluminum (TEAL) is the most important aluminum alkyl and is sold globally in multi-million pound per year quantities. Large amounts of triethylaluminum are used in production of polypropylene. Chlorinated aluminum alkyls, such as diethylaluminum chloride (DEAC) and ethylaluminum sesquichloride (EASC), are less costly than triethylaluminum. However, DEAC and EASC do not perform well with some modern supported... 

This function can be effectively illustrated with a catalyst synthesis used in an early commercial polypropylene process, now obsolete. The catalyst system employed ethylaluminum sesquichloride (EASC) for "prereduction" of TiCl in hexane (eq 4.5). EASC reduces the oxidation state of titanium and TiClj precipitates as the P (brown) form. Reduction is believed to proceed through an unstable alkylated TP" species (eq 4.5) which decomposes to TP (eq 4.6). Lower oxidation states (Ti+ ) may also be formed. These reactions are exothermic and very fast. 

Derivation Reaction of aluminum chloride with ethylaluminum sesquichloride. 

Chlorine is virtually absent in the copolymer produced in the azobisisobutyronitrile (AIBN) catalyzed copolymerization of styrene and maleic anhydride in the presence of chloroform or carbon tetrachloride (3, 4), or of p-dioxene and maleic anhydride in the presence of acrylonitrile in chloroform (5). This absence indicates that trichloromethyl radicals generated by the reaction of the chlorinated hydrocarbons with the radicals from AIBN are not incorporated into the polymer chain. Similarly, there is little or no cnlorine in the alternating copolymer that is formed in the copolymerization of styrene and methyl methacrylate in the presence of ethylaluminum sesquichloride (EASC) in the presence of chloroform and carbon tetrachloride, and with or without a peroxide initiator (6). 

Activation of the AI metal is essential for the reaction with organic chlorides and bromides. These reactions are unimportant industrially as compared with the advantage of the direct synthesis (see 5.3.3.2.1) followed by redistributions with AIX3 (see 5.3.3.3.2) but they are important in the laboratory. The preparation of the methyl- and ethylaluminum sesquichlorides or -bromides is detailed . However, even following the exact experimental instructions does not insure completely against failure. A potential hazard derives from the slow initiation and highly exothermic reaction. 

Using the available ethylaluminum sesquichloride (see 5.3.3.2.2) instead of AICI3, a growth factor of three can be obtained ... 

Modifications are possible -. Thus ethylaluminum sesquichloride can be converted quantitatively to Et2AlCl. Another advantage is the precipitation of finely divided and active Al metaU. This can again be utilized in the preparation of aluminum sesquihalides. 

ETHYLALUMINUM SESQUICHLORIDE, 15% SOLUTION IN HYDROCARBONS (12075-68-2) Forms explosive mixture in air [flash point (based on hexane) —IA°FI —26°C], Once solvent has evaporated, this substance is pyrophoric this is dangerous on organic materials (wood, cloth, grease, etc.). Flow or agitation of substance may generate electrostatic charges due to low conductivity. See also above entry. 

EASC. See Ethylaluminum sesquichloride Ease Reiease 700, Ease Reiease 2148, Ease... 

Uses Catalyst for Ziegler-Natta polymerization of olefins and dienes reactant in prod, of transition metal catalysts alkylating agent for prod, of organotin compds. and organophosphorus derive. organic synthesis ManufJDistrib. Akzo Nobel http //www. akzonobel. com Ethylaluminum sesquichloride CAS 12075-68-2 EINECS/ELINCS 235-137-7 UN UN 3052... 

Trichlorotriethyidialuminum. See Ethylaluminum sesquichloride Trichlorotrifluoroethane CAS 76-13-1 EINECS/ELINCS 200-936-1 Synonyms CFC 113 Chlorofluorocarbon 113 Ethane, 1,1,2-trichloro-1,2,2-trifluoro FC 113 Fluorocarbon 113... 

Triethyidialuminum trichloride. See Ethylaluminum sesquichloride Triethylene diamine... 

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