Catalytic oxidation of organic compounds is an extremely important field of chemistry, spanning the range from biological oxidations to large scale industrial production of commodity chemicals. However, many of these transformations can hardly be classified as organometallic reactions, since the catalysts (often simple metal salts) and the intermediates can be rather regarded as coordination complexes than organometallic compounds.
The realm of aqueous organometallic catalysis incorporates many more reactions and catalysts than discussed in the preceeding chapters. However, these were not investigated in so much detail as, for instance, hydrogenation or hydroformylation; some of them are mentioned only here and there. An attempt is made to give a representative sample of these studies.
Synthetic organic chemistry is equivalent to systematic making and breaking chemical bonds of which the manipulation of carbon-carbon bonds plays an extraordinary role in construction of an organic molecule. Traditionally this chemistry was carried out in organic solutions, however, water or partially aqueous solvents gain more and more significance in organic synthesis recently. To attempt a comprehensive description of this field would be a hopless venture these days, and this chapter gives only examples of the most important ways of carbon-carbon bond formation in aqueous media. ...
The annual production of various polymers can be measured only in billion tons of which polyolefins alone figure around 100 million tons per year. In addition to radical and ionic polymerization, a large part of this huge amount is manufactured by coordination polymerization technology. The most important Ziegler-Natta, chromium- and metallocene-based catalysts, however, contain early transition metals which are too oxophilic to be used in aqueous media.
Drugs li KT used in Hyperlipoproteinemias
port vehicles in the aqueous media of lymph and blood. To this end, small amounts of lipid are coated with a layer of phospholipids, embedded in which are additional proteins—the apolipoproteins (A). According to the amount and the composition of stored lipids, as well as the type of apolipoprotein, one distinguishes 4 transport forms:
Lipid-Lowering Agents Triglycerides and cholesterol are essential constituents of the organism.
The domain of catalytic hydrogenation continues to grow fast, reflecting the wide range of chemical applications that can be enhanced by the easy use of molecular hydrogen. The advances in characterization techniques and their application have improved our understanding of the catalytic processes and mechanisms occurring in both homogeneous and heterogeneous catalysis.
Zhou et al. Nanoscale Research Letters 2011, 6:364 http://www.nanoscalereslett.com/content/6/1/364
Electro-synthesis of novel nanostructured PEDOT films and their application as catalyst support
Cuifeng Zhou1, Zongwen Liu1*, Yushan Yan2, Xusheng Du3*, Yiu-Wing Mai3 and Simon Ringer1
Abstract Poly(3,4-ethylenedioxythiophene) (PEDOT) films doped with nitric and chlorine ions have been electrochemically deposited simply by a one-step electrochemical method in an aqueous media in the absence of any surfactant.
A comprehensive study of the hydration mechanism of an enzyme in non-aqueous media was done using molecular dynamics simulations in five
organic solvents with different polarities, namely, hexane, 3-pentanone,
diisopropyl ether, ethanol, and acetonitrile.
In aqueous media, muscle pyruvate kinase is highly
selective for K
. We now studied the selec-tivity of pyruvate kinase in water/dimethylsulfoxide mix-tures by measuring the activation and inhibition constants
, i.e. their binding to the monovalent and
divalent cation binding sites of pyruvate kinase, respect-ively [Melchoir J.B. (1965) Biochemistry4, 1518–1525]. In
40% dimethylsulfoxide theK0.5 appfor K
190 and 64-fold lower than in water.Kiappfor K
+decreased 116 and 135-fold between 20 and 40%
The electrooxidation of 5-hydroxy-1,4-naphthoquinone (JUG) in organic media leads to conducting polymer film on glassy and Pt electrodes. The IR ex situ, IR in situ (MIRFTIRS) during the film formation, XPS studies indicate that electropolymerization occurs via the OH group while quinone group on the other ring remains intact and shows a very good electro activity and stability in different media, particularly in aqueous, biocompatible one.