Sulfonic acid resins, complexed with

Polymeric resin sulfonic acids including sulfonic acid resins complexed with Lewis acids and perfluorinated polymer resin acids (Nafion-H and Nafion-silica nanocomposites). 

Polymer-supported tetrabromooxomolybdate(V) was claimed to be a heterogeneous catalyst for alcohol oxidations with TBHP . However, it seems likely that molybdenum is leached from the surface and the observed catalysis may be, at least partially, homogeneous in nature. The same applies to Cr(III) and Ce(IV) catalysts supported on a perfluorinated sulfonic acid resin (Nafion K) which catalyze the oxidation of alcohols with TBHP . Similarly, vanadium-pillared montmorillonite clay (V-PILC) ° and a zeolite-encapsulated vanadium picolinate complex were shown to catalyze... 

While considerable difference in binding is observed, in the case of the sulfonic acid polymers we can ascribe coulombic binding as being responsible with the alkali metal, quaternary ammonium, alkaline earth and transition metal cations. Coulombic binding can explain the relative uptake of the alkaline earth cations by sulfonic acid resins where the sequence Ba>Sr>Ca>Mg is observed. These phenomena have a higher order of complexity than with the alkali metal cations because binding must occur at two adjacent sites. 

Solid Superacids. Most large-scale petrochemical and chemical industrial processes ate preferably done, whenever possible, over soHd catalysts. SoHd acid systems have been developed with considerably higher acidity than those of acidic oxides. Graphite-intercalated AlCl is an effective sohd Friedel-Crafts catalyst but loses catalytic activity because of partial hydrolysis and leaching of the Lewis acid halide from the graphite. Aluminum chloride can also be complexed to sulfonate polystyrene resins but again the stabiUty of the catalyst is limited. 

Nafion-H (144), a perfluorinated resin-sulfonic acid, is an efficient Bronsted-acid catalyst which has two advantages it requires only catalytic amounts since it forms reversible complexes, and it avoids the destruction and separation of the catalyst upon completion of the reaction [94], Thus in the presence of Nafion-H, 1,4-benzoquinone and isoprene give the Diels-Alder adduct in 80% yield at 25 °C, and 1,3-cyclohexadiene reacts with acrolein at 25 °C affording 88 % of cycloadduct after 40 h, while the uncatalyzed reactions give very low yields after boiling for 1 h or at 100 °C for 3.5 h respectively [95], Other examples are given in Table 4.24. In the acid-catalyzed reactions that use highly reactive dienes such as isoprene and 2,3-dimethylbutadiene, polymerization of alkenes usually occurs with Nafion-H, no polymerization was observed. 

The axial immobilization of chiral [Mn((S,S)-salen )j (where salen = (Si,Sj-NiN -bis(3,5-diR -salicylidene)-l,2-diRbethane-diamine R = Bu, R -R = -(CH2)4- R = Bu, R = Ph R = Pn, R R = -(CH2)4-) complexes was achieved by reaction of [Mn(salen )Cl] with sulfonic acid- or phenol-substituted crosslinked and insoluble polystyrene resins [45]. The resulting polymer-immobilized [Mn(salen )j complexes were active and enantioselective for the asymmetric epoxidation of... 

Purification of food dyes can also be accomplished by means of anion-exchange resins. Theoretically, the anionic resin combines with sulfonic acid groups in the dye molecule to form a complex. Since food dyes may be adsorbed onto carbohydrates or chemically bound to proteins, the resin must have greater affinity for the color than to any of these adsorbents (156,161). Usually... 

Alkylphenol. Alkylphenol is a common surfactant intermediate used to produce alkylphenol ethoxylates. Phenol reacts with an olefin thermally without a catalyst but with relatively poor yields. Catalysts for the reaction include sulfuric acid p-toluene sulfonic acid (PTSA), strong acid resins, and boron trifluoride (BF3). Of these, strong acid resins and BF3 are mostly widely used for the production of surfactant-grade alkylphenols. The most common alkylphenols are octylphenol, nonylphenol, and dodecylphe-nol. Mono nonylphenol (MNP) is by far the most common hydrophobe. It is produced by the alkylation of phenol with nonene under acid conditions. All commercially produced MNP is made with nonene based on propylene trimer. Because of the skeletal rearrangements that occur during propylene oligomerization, MNP is a complex mixture of branched isomers. 

There is experimental evidence to support the estimate that t/H = t/Na in this system. In the research of Travers and one of the present authors (2), a study of the complexation of divalent metal ions by poly-methacrylic acid (PMA) showed that deviation from ideality with a of the divalent ions exposed to the same potential as the H+ ion was described exactly by the deviation term deduced from the potentiometric properties of the PMA. Additional evidence for this estimate is available in the ion-exchange literature (3,4,5). At a relatively low cross-linking percentage (2 wt % divinyl benzene) j/h is about equal to t/Na> as evidenced by the ion-exchange distribution of Na+ and H+ between a polystyrene sulfonate-based resin and a simple dilute electrolyte mixture of Na+ and H+ (Na H+, X"). The selectivity coefficient measured over the complete composition range of the resin deviates very little from unity to demonstrate this as an experimental fact (KHNa = 1.02 zt 0.02... 

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