Additional Organic Compounds

Carbonyl group Ketones Aldehydes Carboxylic acids Carboxyl group Ester Polymer 

A hydrocarbon derivative containing the carbonyl group bonded to two carbon atoms 

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After reviewing the health effects and chemical/physical property data bases, EPA has tentatively selected about 40 additional organic compounds for inclusion in the Toxicity Characteristic at this time (Tab. 1). EPA anticipates that the list of toxicants to be included in the Toxicity Characteristic will be periodically expanded as more information regarding additional compounds is developed. 

Polymer liquid (PL) membranes The PL membrane is a relatively new type of self-supporting liquid membrane, which resembles the SL membrane. Similarly to the SL membrane, the PL membrane incorporates a liquid extractant in the membrane polymeric structure. In some cases the incorporation of additional organic compounds (plasticizers) is required to achieve homogeneity and sufficient flexibility of the membrane. 

Protecting metallic substrates against corrosion is one of the prime functions of most coatings. Corrosion resistant coatings are typically formulated using anticorrosive pigments and suitable binders with the optimum formulation parameters. In addition, organic compounds known as corrosion inhibitors are often added at low levels, and can effectively reduce the corrosion rate of a metal or slow down the individual corrosion reactions. 

The bath was being used to electro-polish aluminum furniture, and despite knowing the explosive dangers of the bath, the plant chemist, Robert M. McGee, allowed production to continue after the refrigeration system, to keep the batch cool, failed. In addition, organic compounds were added to the overheating bath when an iron rack was replaced with one coated with cellulose acetobutyrate (Tenit-2 plastic). A few minutes later the bath exploded. 

The additives for improving the cetane number, called pro-cetane, are particularly unstable oxidants, the decomposition of which generates free radicals and favors auto-ignition. Two families of organic compounds have been tested the peroxides and the nitrates. The latter are practically the only ones being used, because of a better compromise between cost-effectiveness and ease of utilization. The most common are the alkyl nitrates, more specifically the 2-ethyl-hexyl nitrate. Figure 5.12 gives an example of the... 

The surface tensions for solutions of organic compounds belonging to a homologous series, for example, R(CH2)nX, show certain regularities. Roughly, Traube [145] found that for each additional CH2 group, the concentration required to give a certain surface tension was reduced by a factor of 3. This rule is manifest in Fig. lll-15b the successive curves are displaced by nearly equal intervals of 0.5 on the log C scale. 

The bromine test is applied first. The organic compound, if a liquid, is treated with 2-3 drops of liquid bromine or (preferably) a solution of bromine in carbon tetrachloride if the organic compound is a solid, it should first be dissolved in cold carbon tetrachloride or chloroform. The rapid absorption of the bromine (and consequent disappearance of the red colour) is a strong indication that the compound is unsaturated, and is therefore undergoing direct addition of the bromine. 

The sodium fusion and extraction, if performed strictly in accordance with the above directions, should be safe operations. In crowded laboratories, however, additional safety may be obtained by employing the follow ing modification. Suspend the hard-glass test-tube by the rim through a hole in a piece of stout copper sheet (Fig. 69). Place 1 -2 pellets of sodium in the tube, and heat gently until the sodium melts. Then drop the organic compound, in small quantities at a time, down — =. the tube, allowing the reaction to subside after each addition before the next is made. (If the compound is liquid, allow two or three small drops to fall at intervals from a fine dropping-tube directly on to the molten sodium.) Then heat the complete mixture as before until no further reaction occurs. 

In addition to water and ether, the following reagents are employed as solvents for the characterisation of organic compounds 5 per cent, aqueous solutions of hydrochloric acid and of sodium hydroxide, and also concentrated sulphuric acid. 

Many semiempirical methods have been created for modeling organic compounds. These methods correctly predict many aspects of electronic structure, such as aromaticity. Furthermore, these orbital-based methods give additional information about the compounds, such as population analysis. There are also good techniques for including solvation elfects in some semiempirical calculations. Semiempirical methods are discussed further in Chapter 4. 

Organic compounds M—R and hydrides M—H of main group metals such as Mg, Zn, B, Al, Sn, SI, and Hg react with A—Pd—X complexes formed by oxidative addition, and an organic group or hydride is transferred to Pd by exchange reaction of X with R or H. In other words, the alkylation of Pd takes place (eq. 9). A driving force of the reaction, which is called transmetallation, is ascribed to the difference in the electronegativities of two metals. A typical example is the phenylation of phenylpalladium iodide with phenyltributyltin to form diphenylpalladium (16). 

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