Olefins, polymerized, synthetic

Chromyl chloride is used in many organic synthetic reactions including oxidation and chlorination. It also is used as a catalyst in olefin polymerization in the preparation of chromium complexes and as a solvent for chromic anhydride. 

The coordination catalysts were quickly extended to dienes and found to produce the long-sought objective of a "synthetic natural rubber, i.e., cis-1,4-polyisoprene. cis-1,4-Polybutadiene was also quickly produced. These were, and still are, erroneously referred to as stereo rubbers. They are actually unique geometric isomers rather than stereoisomers, but the name stereo rubber became established probably because of the relationship in time and catalyst usage to stereo olefin polymerization. 

The pooled encoded format was also used by Boussie and co-workers (179, 180) to prepare and screen Pd- and Ni-diimine ligand complexes as olefin polymerization catalytic systems. The successful application of deconvolutive or encoding methods to medium-large SP catalytic system pool libraries should become routine in the future. Careful validation of the synthetic scheme, the screening, and the detection methods will ensure the applicability of HTS of SP catalytic pool libraries to each specific transformation investigated. 

Yang, X. Stern, C.L. Marks, T.J. Cationic zirco-nocene olefin polymerization catalysts based on the organo-Lewis acid tris(pentafluorophenyl)-borane. A synthetic, structural, solution dynamic, and polymerization catalytic study. J. Am. Chem. Soc. 1994, 116, 10,015. 

Synthetic motor oils are made of a synthesized hydrocarbon base oil of hydrogenated polydecene, decanoic acid esters, zinc alkyl dithiophosphate, and synthetic poly alpha olefins. Most synthetic oils also contain additives, detergents, and corrosion inhibitors as well as viscosity modifiers. It is believed that the first synthesized polymeric hydrocarbons were synthesized in 1877, yet it was not until 1929 that the commercial development of synthetic lubricants was undertaken. Because of the availability of commercial petroleum-based lubricants, these synthetic lubricants were ultimately unsuccessful. The advent of commercial jet travel spurred the development of the first commercially successful synthetic lubricant, Mobil 1, in 1975. This lubricant had superior resistance to thermal breakdown and lower friction properties than petroleum-based products. 

Carbosilane dendrimers containing titanium and zirconium complexes on their periphery have been prepared and used in olefin polymerization reactions.Generally, the best synthetic route to these materials involves the synthesis of generations of suitably functionalized dendrimers to which the metal is added in the final step giving products such as 276. Routes involving the incorporation of pre-metallated building blocks gave only low yields of the desired dendrimers. 

F. A. Cotton. He moved to Northwestern University as an assistant professor In 1970. His research Interests Include synthetic and mechanistic f- and d-element organometallic chemistry, particularly with applications In olefin polymerization catalysis, as well as the design, synthesis, and physicochemical properties of unususal molecules and molecule-derived materials. 

Despite its unique effectiveness as a cocatalyst, MAO still remains a black box . Depending on the nature of the hydrated salt (the H2O source) used for the MAO synthesis and the exact MAO synthetic reaction conditions, MAO-activated metallocenes may exhibit widely differing activities in olefin polymerization. The MAO structure can hardly be elucidated directly because of the multiple equilibria present in MAO solutions, and residual trimethylaluminum in MAO solutions appears to participate in equilibria that interconvert various MAO oligomers. There are two types of TMA present in typical MAO solutions free TMA and associated TMA (eq 3). 

Altifiough [B(C6Fs)4] -based activators have proven to be highly effective for olefin polymerization, they suffer from poor solubility in hydrocarbons and especially poor thermal stability and crystallizability of the cationic complexes derived therefrom, which results in very short catalytic lifetimes and limits the useful tools to characterize these species. For this reason, functionalized fluoroarylborate salts (9) have been synthesized according to the synthetic Scheme... 

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