Coupling carbon dioxide

Nielsen, A. M. Beck, J. V. (1972). Chalcocite oxidation and coupled carbon dioxide fixation by Thiobacillus ferrooxidans. Science, 175, 1124—6. 

The main advantage of UNCAs 7 (see Table IjP relative to classical NCAs or Leuchs anhydridesP l is their greater stability and lack of sensitivity toward polymerization. Upon coupling, carbon dioxide is released, which is a distinct advantage compared to other... 

Carbon dioxide is a thermodynamically very stable molecule because the carbon is in the highly oxidized state and requires reactive compoimds and effective catalysts for its activation. However, due to the electron deficiency of the carbonyl carbon, carbon dioxide has a strong affinity toward nucleophiles and electron-donating reagents [9]. One class of the important chemical products that can be synthesized from CO is the organic cyclic carbonates by coupling carbon dioxide and epoxides as nucleophiles. Organic cyclic carbonates are valuable chemicals that can be used as electrolyte precursors for the pharmaceutical and fine chemical intermediates. 

Electroreductive coupling of ben2otrifluorides with sacrificial aluminum or magnesium anodes in the presence of acetone, carbon dioxide, or /V, /V-dimethylformamide provides a novel route to ArCF2-derivatives (310). 

Mounting electrodes in a bioreactor is costly, and there is an additional contamination risk for sensitive cell cultures. Some other sensors of prac ticai importance are those for dissolved oxygen and for dissolved carbon dioxide. The analysis of gas exiting from a bioreactor with an infrared unit that detects carbon dioxide or a paramagnetic unit that detects oxygen (after carbon dioxide removal) has been replaced by mass spec trophotometry. Gas chromatographic procedures coupled with a mass spectrophotometer will detect 1 the volatile components. 

Perfluoroalkyl iodides can be directly carboxylated with zinc and carbon dioxide under ultrasonic conditions [39] (equation 45) or by the reaction of perfluoroalkyl iodides with carbon dioxide with a zinc-copper couple in DMSO [57] (equation 46) Alkylation of the intermediate carboxylate gives the corresponding ester [52]... 

H. Daimon and Y. Hirata, Direct coupling of capillary supercritical fluid chromatography with superaitical fluid extraction using modified carbon dioxide , J. High Resolut. Chromatogr. 17 809-813 (1994). 

The coupling of supercritical fluid extraction (SEE) with gas chromatography (SEE-GC) provides an excellent example of the application of multidimensional chromatography principles to a sample preparation method. In SEE, the analytical matrix is packed into an extraction vessel and a supercritical fluid, usually carbon dioxide, is passed through it. The analyte matrix may be viewed as the stationary phase, while the supercritical fluid can be viewed as the mobile phase. In order to obtain an effective extraction, the solubility of the analyte in the supercritical fluid mobile phase must be considered, along with its affinity to the matrix stationary phase. The effluent from the extraction is then collected and transferred to a gas chromatograph. In his comprehensive text, Taylor provides an excellent description of the principles and applications of SEE (44), while Pawliszyn presents a description of the supercritical fluid as the mobile phase in his development of a kinetic model for the extraction process (45). 

The poor efficiencies of coal-fired power plants in 1896 (2.6 percent on average compared with over forty percent one hundred years later) prompted W. W. Jacques to invent the high temperature (500°C to 600°C [900°F to 1100°F]) fuel cell, and then build a lOO-cell battery to produce electricity from coal combustion. The battery operated intermittently for six months, but with diminishing performance, the carbon dioxide generated and present in the air reacted with and consumed its molten potassium hydroxide electrolyte. In 1910, E. Bauer substituted molten salts (e.g., carbonates, silicates, and borates) and used molten silver as the oxygen electrode. Numerous molten salt batteiy systems have since evolved to handle peak loads in electric power plants, and for electric vehicle propulsion. Of particular note is the sodium and nickel chloride couple in a molten chloroalumi-nate salt electrolyte for electric vehicle propulsion. One special feature is the use of a semi-permeable aluminum oxide ceramic separator to prevent lithium ions from diffusing to the sodium electrode, but still allow the opposing flow of sodium ions. 

The major electrochemical reaction at the anode surface is oxygen and chlorine evolution coupled with oxidation of the active carbon to carbon dioxide. Eventually all the carbon is removed from the anode coating and this allows perforation of the copper conductor leading to ultimate anode failure. 

Oxygen infiltration coupled with (steam volatile) carbon dioxide produces enhanced condensate line corrosion. The corrosion rate of steel in the system is particularly high when both gases are present. 

Climate is often viewed as the aggregate of all of the elements of weather, with quantitative definitions being purely physical. However, because of couplings of carbon dioxide and many other atmospheric species to both physical climate and to the biosphere, the stability of the climate system depends in principle on the nature of feedbacks involving the biosphere. For example, the notion that sulfate particles originating from the oxidation of dimethylsulfide emitted by marine phytoplankton can affect the albedo (reflectivity) of clouds (Charlson et ai, 1987). At this point these feedbacks are mostly unidentified, and poorly quantified. 

The Grignard reagents prepared from the activated magnesium appear to react normally with electrophiles. Thus reactions with proton donors, ketones, and carbon dioxide afford hydrocarbons, alcohols, and carboxylic acids, respectively. The reductive coupling of ketones to pinacols had also been accomplished with the activated magnesium. ... 

Pyridine compounds 45 can also be produced by the NHC-Ni catalysed cycloaddition between nitriles 43 and diynes 44 (Scheme 5.13) [16]. The SIPr carbene was found to be the best ligand for the nickel complex in this reaction. The reaction required mild reaction conditions and low catalyst loadings, as in the case of cycloaddition of carbon dioxide. In addition to tethered aUcynes (i.e. diynes), pyridines were prepared from a 3-component coupling reaction with 43 and 3-hexyne 23 (Scheme 5.13). The reaction of diynes 44 and nitriles 43 was also catalysed by a combination of [Ni(COD)J, NHC salts and "BuLi, which generates the NHC-Ni catalyst in situ. The pyridines 45 were obtained with comparable... 

Bubbles of carbon dioxide gas form when the vinegar hits the chalk. A piece of chalk covered in vinegar and left for a couple of days will completely dissolve. Limestone rocks dissolve in carbonic acid to form limestone caves, and marble buildings and statues will eventually dissolve in acidic rain, too. 

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