Sulfonic acid substitution

Solution "What is an immediate precursor of the target " The final step will involve introduction of one of three groups—chlorine, propyl, or sulfonic acid—so we have to consider three possibilities. Of the three, the chlorination of o-propylbenzene-sulfonic acid can t be used because the reaction would occur at the wrong position. Similarly, a Friedel-Crafts reaction can t be used as the final step because this reaction doesn t work on sulfonic acid-substituted (strongly deactivated) benzenes. Thus, the immediate precursor of the desired product is probably m-chloropropyl-benzene, which can be sulfonated to give a mixture of product isomers that must then be separated. 

Acrylic acid terpolymers have appeared on the market in recent years. With their broad spectrum of functions, they offer the potential for excellent waterside conditions. In particular, the terpolymers have proved to be very effective particulate iron oxides dispersants and colloidal iron stabilizers. Examples include acrylic acid/sulfonic acid/sodium styrene sulfonate (AA/SA/SSS), such as Good-Rite K781, K797, K798. A further example is acrylic acid/ sulfonic acid/substituted acrylamide (AA/SA/NI), such as Acumer 3100. 

Acrylic add/sulfonic acid/sodium styrene sulfonate 447 Acrylic add/sulfonic acid/substituted acrylamide 447... 

AA/SA AA/SA/NI AA/SA/SSS sulfonate (polymer) aciylic acid/sulfonic acid aciylic acid/sulfonic acid/ nonionic (polymer) aciylic acid/sulfonic acid/sodium styrene sulfonate acrylic acid/sulfonic acid/substituted acrylamide (polymer)... 

To reach the reductive step of the azo bond cleavage, due to the reaction between reduced electron carriers (flavins or hydroquinones) and azo dyes, either the reduced electron carrier or the azo compound should pass the cell plasma membrane barrier. Highly polar azo dyes, such as sulfonated compounds, cannot pass the plasma membrane barrier, as sulfonic acid substitution of the azo dye structure apparently blocks effective dye permeation [28], The removal of the block to the dye permeation by treatment with toluene of Bacillus cereus cells induced a significant increase of the uptake of sulfonated azo dyes and of their reduction rate [29]. Moreover, cell extracts usually show to be more active in anaerobic reduction of azo dyes than whole cells. Therefore, intracellular reductases activities are not the best way to reach sulfonated azo dyes reduction the biological systems in which the transport of redox mediators or of azo dye through the plasma membrane is not required are preferable to achieve their degradation [13]. 

Cross-linked, sulfonic-acid-substituted, polyphosphazene-based PEMs have primarily been examined for potential use in DMFC applications due to their low MeOH crossover with reported values 2.5 times lower than that of Nafion. These materials have also been shown to display good thermomechanical and chemical stability (in a Fenton test). Sulfonamide-substituted polyphosphazenes have exhibited very high power densities that are comparable with Nation and may be suitable for use in PEMFC applications. ... 

Similar reaction has also been carried out with benzoxazoles substituted in the benzo ring with up to three substituents, such as chloro, alkyl, alkoxy,48 phenoxy,49 phenyl, cycloalkyl, or sulfamoyl10 groups. By employing anils of substituted aromatic aldehydes, varying groups may also be introduced into the stilbene part of the molecule.50 Water-soluble derivatives have also been obtained by the use of sulfonic acid-substituted p-tolylbenzoxazoles and also aromatic aldehyde anils.51... 

AA/SA/NI Acrylic acid/sulfonic acid/substituted acrylamide... 

Arco have developed an integrated process for the production of industrially important epoxides via an adapted AO process (Figure 1.13).33 34 A sulfonic acid substituted alkylhydroanthraquinone alkylammonium salt is reacted with molecular oxygen to form the alkylanthraquinone and hydrogen peroxide. The hydrogen peroxide is then reacted with an alkene in the presence of a titanium zeolite catalyst (TS-1 see Chapter 4). The epoxide product is then separated, and the anthraquinone salt recycled to a hydrogenator for reaction with... 

Activation of the copolymer is carried out by sulfonation of the matrix with hot sulfuric acid thereby introducing the sulfonic acid functional group giving a strongly acidic cation exchange resin. The reaction in Scheme 2.2 shows sulfonic acid substitution occurring within the styrene nucleus only, but whether or not all aromatic nuclei become sulfonated is a subject of some debate. Subsequent... 

Metal complexes of various porphyrins 47, phthalocyanines 48 and naphthalocyanines 49, with intense absorptions in the visible region of light, have also been covalently bound to macromolecular carriers. Early work in this field was reviewed in 1977 and 1983 [124,125], These reviews, for example, reported the fixation of metal-free and metal-containing protoporphyrin-IX, chlorophyll, mesoporphyrin-IX and substituted 5,10,15,20-tetraphenyl-porphyrins. The binding of substituted phthalocyanines to substituted polymers has also been reviewed [125,126] and covers mainly the binding of carboxylic or sulfonic acid-substituted phthalocyanines to polystyrene. 

Variations in structure that affect the color of the azo compounds may involve both the aromatic rings and their substituents. Using naphthalene rings for both the diazonium ion and the activated ring produces compounds with different colors. For example, the product of azo coupling of the para sulfonic acid-substituted benzenediazonium ion with 2-naphthol is orange, whereas the product obtained using a similarly substituted naphthalenediazonium ion with 2-naphthol is red. 

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