Selectivity alkylbenzene

Wilson, B.H., Smith, G.B., Rees, J.F. (1986) Biotransformations of selected alkylbenzenes and halogenated ahphatic hydrocarbons in methanogenic aquifer material A Microcosm Study. Environ. Sci. Technol. 20, 997-1002. 

Wilson BH, Smith GB, Rees JF. 1986. Biotransformation of selected alkylbenzenes and halogenated hydrocarbons in methanogenic aquifer material A microcosm study. Environ Sci Technol 20 997-1002. 

To evaluate the importance of multivalent cation precipitation of surfactants by multivalent cations present in the formation brine or resulting from cation exchange and dissolution of minerals such as limestone, dolomite, etc., a very limited study of the calcium tolerance of selected alkylbenzene sulfonates was undertaken. 

If acetoxylation were a conventional electrophilic substitution it is hard to understand why it is not more generally observed in nitration in acetic anhydride. The acetoxylating species is supposed to be very much more selective than the nitrating species, and therefore compared with the situation in (say) toluene in which the ratio of acetoxylation to nitration is small, the introduction of activating substituents into the aromatic nucleus should lead to an increase in the importance of acetoxylation relative to nitration. This is, in fact, observed in the limited range of the alkylbenzenes, although the apparently severe steric requirement of the acetoxylation species is a complicating feature. The failure to observe acetoxylation in the reactions of compounds more reactive than 2-xylene has been attributed to the incursion of another mechan-104... 

The comparative ease with which a benzylic hydrogen is abstracted leads to high selectivity m free radical halogenations of alkylbenzenes Thus chlorination of toluene... 

Halogenation (Section 11 12) Free radical halo genation of alkylbenzenes is highly selective for substitution at the benzylic position In the exam pie shown elemental bromine was used Alterna Lively N bromosuccinimide is a convenient re agent for benzylic bromination... 

The newer HFC refrigerants are not soluble in or miscible with mineral oils or alkylbenzenes. The leading candidates for use with HFC refrigerants are polyol ester lubricants. These lubricants are derived from a reaction between an alcohol and a normal or branched carboxyflc acid. The most common alcohols used are pentaerythritol, trimethylolpropane, neopentjlglycol, and glycerol. The acids are usually selected to give the correct viscosity and fluidity at low temperatures. 

A good deal of experimental care is often required to ensure that the product mixture at the end of a Friedel-Crafts reaction is determined by kinetic control. The strong Lewis acid catalysts can catalyze the isomerization of alkylbenzenes, and if isomerization takes place, the product composition is not informative about the position selectivity of electrophilic attack. Isomerization increases the amount of the meta isomer in the case of dialkylbenzenes, because this isomer is thermodynamically the most stable. ... 

Seddon, K.R. Stark, A. (2002) Selective Catalytic Oxidation of Benzyl Alcohol and Alkylbenzenes in Ionic Liquids. Green Chemistry, 4(2), 119-123. 

Synthetic-based muds are mineral oil muds in which the oil phase has been replaced with a synthetic fluid, such as ether, ester, PAO, or linear alkylbenzene, and are available from major mud companies. The mud selection process is based on the mud s technical performance, environmental impact, and financial impact. Synthetic muds are expensive. Two factors influence the direct cost unit or per-barrel cost and mud losses. Synthetic muds are the technical equivalent of oil-based muds when drilling intermediate hole sections. They are technically superior to all water-based systems when drilling reactive shales in directional wells. However, with efficient solids-control equipment, optimized drilling, and good housekeeping practices, the cost of the synthetic mud can be brought to a level comparable with oil-based mud [1308]. 

Alkene Catalyst Alkene conversion (%) Selectivity towards alkylbenzene (%) ... 

Based on their use in industrial and domestic applications and abundance in environmental samples, six surfactants were selected by the participants of interlaboratory study I. Two different standard mixture solutions (standards II and 12) were distributed to all participants for the preparation of the calibration graphs. Standard II contained Arkopal N100 (NPEO), Marlamid DF 1218 (coconut fatty acid diethanolamide, CDEA) and Marlon A 350 (linear alkylbenzene sulfonate, LAS) at 1000 mg L-1 for each compound, while standard 12 contained Rewopol NOS 5 (nonylphenol ethoxylate sulfate, NPEO-SO4),... 

TABLE 2.20 Selected examples of the radical halogenation of alkylbenzenes ... 

The relationship of the selectivity towards rc-electrons can be understood from the differences in the retention factors of polycyclic aromatic hydrocarbons (Figure 3.13). The difference in the retention factors on end-capped and non-endcapped stationary phase materials is less than that of alkylbenzenes. This is due to the water content of the stationary phase. The content may be higher in non-endcapped bonded phases. 

Although the intermolecular selectivity of the nitration of alkylbenzenes by nitric acid in trifluoroacetic acid is controlled by both electronic and steric factors, it is argued that intramolecular selectivity is controlled by steric effects on transition state solvation. 

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