Reaction Condition Control

Comonomers can be incorporated into the growing chain at random or as groups of identical monomers, known as blocks. The polymerization catalyst and reaction conditions control... 

The monomers that comprise copolymers can be introduced in one of three general ways, randomly, as regularly alternating series, or as blocks of identical monomers. The polymerization catalyst and the reaction conditions control the type of comonomer distribution produced. 

L. K. P. Lam, R. A. H. F. Hui, J. B. Jones, Enzymes in Organic Synthesis. 35. Stereoselective Pig Liver Esterase Catalyzed Hydrolyses of 3-Substituted Glutarate Diesters. Optimization of Enantiomeric Excess via Reaction Conditions Control , J. Org. Chem. 1986, 51, 2047 - 2050. 

Efforts have been made to accelerate the reaction. Ionic liquids can be obtained in < 1 min using microwave-assisted preparation, and ultrasound-assisted synthesis leads to the rapid isolation of ionic liquids with high chemical purity. If a microwave reactor with reaction condition control mechanisms is used, ionic liquids can be conveniently prepared even on a large scale (up to 2 moles), both in high yields and with short reaction times. ... 

Six iron-sulfur minerals are stable enough to exist in nature all contain the ferrous (Fe +) form of iron. Those minerals with iron-to-sulfur ratios of 1 1 (FeS) are mackinawite and pyrrhotite. Those with iron-to-sulfur ratios of 3 4 0 0384) are greigite and smythite. All the iron sulfides with ratios of 1 1 and 3 4 are soluble in mild acids with formation of H2S. Those minerals with iron-to-sulfur ratios of 1 2 (FeSj) are pyrite and marcasite. Pyrite and marcasite are distinguished from the other four iron sulfides by their insolubility in concentrated HCl. Pyrite is highly pH- and temperature-stable. Due to this, it is found often in nature. This inertness also makes pyrite a desirable reaction product for sulfide removal using an iron-based scavenger. Various iron sulfides can be formed chemically from iron compounds reacting with soluble sulfides at ambient conditions in aqueous systems. The specific reaction conditions control both the products formed and the rate of reaction. 

The small channel size of a microreactor is of particular advantage for reaction condition control. The high surface/volume ratio and small heat... 

Stabilizing the catalyst against acids was needed for the Rh/BINAS-catalyzed aqueous hydroformylation of internal olefins (see Table 5.1) [8]. Reaction rates were low (averaged TOF = 62h for 2-pentene), but very high regioselectivities of 99% toward the terminal aldehydes were obtained for the hydroformylation of 2-pentene and 2-octene, respectively, under optimized reaction conditions. Controlling pH was found to be essential to increase both the selectivity and the aldehyde yield. Best results were obtained in solutions buffered at pH 8-9, or with additional triethanolamine or TMEDA employed to trap formic acid suggested to be formed in a side reaction. 

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