Zirconium chloride catalyst

Zeolites, 321, 322 Ziegler-Natta catalysts, 174 Zirconium chlorides, 194 Zirconium compounds as catalysts, 188... 

Idemitsu A process for making C6-C18 a-olefins from ethylene, catalyzed by a modified homogeneous Ziegler-Natta catalyst containing a zirconium chloride. Developed by the Idemitsu Petroleum Company in 1988. 

The Ziegler-Natta catalyst trimethylammonium o-methyl-1-(2-hydroxy Icy do hexyl)-carborane zirconium chloride has been prepared and affixed to a Merrifield resin. When used as a polymerization catalyst for vinyl chloride, t-butyl acrylate, styrene, or ethylene, oligomers with molecular weights <6000 daltons were obtained. 

Various Lewis acids have been employed, most commonly BF3-etherate [34,35], but also zinc chloride, stannic chloride, ferric chloride [36], zirconium chloride [37] and titanium chlo-ride/indium chloride [38], with similar results. Recently 18 different oxometallic species were investigated as catalysts, and of these M0O2CI2 (3 mol%) was found to be the most efficient affording thioglycosides in 75-94% yield [39]. 

In all cases the mechanism is adsorption of A, reaction on the surface to form adsorbed B, and desorption of B into the gas phase. Sketch the rate of reaction (per unit mass of catalyst) vs total pressure in each of the above three cases. Also, for comparison, include a sketch of the rate of the homogeneous reaction, assuming that it is first order. Sketches should be for constant composition. 9-11. Thodos and Stutzmanstudied the formation of ethyl chloride, using a zirconium oxide catalyst (on silica gel) in the presence of inert methane,... 

The experimental apparatus, the catalyst synthesis from zirconium chloride, and the catalyst characterization are reported elsewhere ( ). The experiments were conducted in a conventional fixed-bed temperature-programmed desorption apparatus operating at 1 atm total pressure. Water vapor was introduced to the system by sparging helium gas through water at 25 C. 

EINECS 233-058-2 HSDB 2531 Tetrachlorozirconium UN2503 Zirconium chloride Zirconium chloride (ZrCU) Zirconium chloride, tetra- Zirconium tetrachloride Zirconium(IV) chloride (1 4). Source of the pure metal, analytical chemistry, water repellents for textiles, tanning agent, zirconium compounds, special catalysts (Friedel-Crafts, Ziegler). Solid mp = 437 d = 2.8030 LDso (rat orl) = 1588 mg/kg. Cerac, 3973Afomergic Chem Chemetals Noah. 

Homologation-condensation. 3-Acyltetramic acids are accessible from N-acylacetylglycine esters. In turn the latter compounds may be assembled from a-diazo acetamide derivatives and aldehydes with elimination of dinitrogen. Zirconium chloride is a useful catalyst. 

The alkylation of paraSins with olefins to yield higher molecular weight branched-chain paraffins may be carried out thermally or catalyt-ically. The catalysts for the reaction fall into two principal classes, both of which may be referred to as acid-acting catalysts (1) anhydrous halides of the Friedel-Crafts type and (2) acids. Representatives of the first type are aluminum chloride, aluminum bromide, zirconium chloride, and boron fluoride gaseous hydrogen halides serve as promoters for these catalysts. The chief acid catalysts are concentrated sulfuric acid and liquid hydrogen fluoride. Catalytic alkylations are carried out under sufficient pressure to keep at least part of the reactants in the liquid phase. 

Alkylation of isobutane with ethylene in the presence of zirconium chloride took place at 100 under 15 atmospheres pressure (Ipatieff, 1, p. 682). The product was completely paraffinic and consisted chiefly of hexanes, octanes, and decanes. The catalyst was converted to a dark, pasty mass which was still catalytically active as was shown by its re-use in a second experiment with isobutane and ethylene. 

Tetrabutyl titanate Tetraisopropyl titanate p-Toluene sulfonic acid Trifluoromethane sulfonic acid Xylene sulfonic acid Zirconium butoxide catalyst, esterification reactions Chlorosulfuric acid catalyst, esterifying plasticizers Stannous chloride anhydrous catalyst, esterifying polyesters Stannous chloride anhydrous... 

The acylation of arenes with alcohols has been shown to be possible using a palladium chloride catalyst in the presence of f-butylhydroperoxide. In 2-arylpyridines, substitution is directed to the ortho-position and, after initial paUadation, the formation of intermediate (59) is likely before reductive elimination yields the acylated product. The regioselective acetoxylation of indoles, at the 3-position, has been achieved using the palladium-catalysed reaction with phenyliodonium acetate. 3-Acyl indoles may also be prepared using acetyl chlorides with zirconium tetrachloride as a Lewis acid catalyst. 

SCHEME 6 Synthesis of substituted pyrroles using zirconium chloride as catalyst. 

Other catalysts which may be used in the Friedel - Crafts alkylation reaction include ferric chloride, antimony pentachloride, zirconium tetrachloride, boron trifluoride, zinc chloride and hydrogen fluoride but these are generally not so effective in academic laboratories. The alkylating agents include alkyl halides, alcohols and olefines. 

The earliest Ziegler-Natta catalysts were combinations of titanium tetrachloride (T1CI4) and diethylalummum chloride [(CH3CH2)2A1C1] but these have given way to more effective zirconium based metallocenes the simplest of which is bis(cyclopentadi enyl)zirconmm dichlonde (Section 14 14)... 

Dichlorotoluene (2,4-dichloro-l-methylben2ene) constitutes 80—85% of the dichlorotoluene fraction obtained in the chlorination of PCT with antimony trichloride (76) or zirconium tetrachloride (77) catalysts. It is separated from 3,4-dichlorotoluene (l,2-dichloro-4-methylben2ene), the principal contaminant, by distillation. Chlorination of OCT with sulfuryl chloride gives mainly 2,4-dichlorotoluene and small amounts of the 2,3 isomer (78). 

Early attempts by Asinger to enlarge the scope of hydroalumination by the use of transition metal catalysts included the conversion of mixtures of isomeric linear alkenes into linear alcohols by hydroalumination with BU3AI or BU2AIH at temperatures as high as 110°C and subsequent oxidation of the formed organoaluminum compounds [12]. Simple transition metal salts were used as catalysts, including tita-nium(IV) and zirconium(IV) chlorides and oxochlorides. The role of the transition metal in these reactions is likely limited to the isomerization of internal alkenes to terminal ones since no catalyst is required for the hydroalumination of a terminal alkene under these reaction conditions. 

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