Chloride-ion exchange with

Belluco, Palazzi and Parker have attempted to correlate the difference in the term, for chloride ion exchange with [PtCl2(PEt3)2], with solvent activity coefficients in methanol and dimethylsulphoxide, and have contrasted the behaviour with chloride ion exchanges at tetrahedral carbon centres. They are contrasting the response of the following two reactions to solvent transfer ... 

PVF2/PMMA blends with organoclay (based on dimethyl dioctadecyl ammonium chloride ion exchanged with Na montmorillonite) were noted to exhibit increased exfoliation with increasing PMMA content [6]. A modest increase in modulus in the glassy state was observed with organoclay addition, whereas in the rubbery state, a more pronounced reinforcement was... 

Salt (ionic strength) gradients in lEC discussed in Section 5.4.3.3 are frequently used in the separation of complex peptides, proteins, and other biopolymer samples as a complementary technique to RP solvent gradient separations, often in a 2D setup [99,100]. The gradients usually start at a low salt (chloride, sulfate, etc.) concentration and typically run from 0.005 to 0.5 M. A buffer is used to control the pH acetonitrile and methanol may be added to improve the resolution and urea to improve the solubility of proteins that are difficult to dissolve. Ion exchangers with not strongly hydrophobic matrices usually prevent protein denaturation in aqueous mobile phases. 

The other mechanism, known as hquid-hquid ion-exchange, involves water insoluble extractant such as Ahquat-336 (tri-caprylylmethyl ammonium chloride) and counter-transport of a second anion to provide electroneutrality. In a typical situation, the removal of cephalosporin anion, P" from the aqueous phase by an ion exchange with the anion. Cl" of the extractant (QCl) dissolved in the organic phase takes place according to... 

With both the Fu and the Denmark catalysts it can be assumed that catalysis is effected by formation of a highly electrophilic silicon cation D from tetrachlorosi-lane and the nucleophilic catalyst C, i.e. by attack of the pyridine N-oxide or of the phosphoramide O-atom on silicon, followed by ionization (Scheme 13.38). The latter cation can then activate the epoxide toward nucleophilic attack by the chloride ion. Exchange of the product silane for another molecule of tetrachlorosilane completes the catalytic cycle [75],... 

The PVC membrane compositions consist of a neutral carrier and ion exchange ionophores as indicated in Table I. The K membrane includes valinomycin as the ionophore and is plasticized by 2-ethyl-hexyladipate (Fluka). The Na+ membrane contains methyl monensin and tris(2-ethylhexyl)phthalate. Tri-n-dodeclyamine is the ionophore for pH and tridodecylmethyammonium chloride is the ion exchanger for Cl. HC03 utilizes 4-butyltrifluorophenone for C03 detection as well as trioctylammonium chloride ion exchanger. Both anion membranes are plasticized with dioctyladipate. 

In contrast, Kim et al. (13) found that the amount of aluminum removed from the zeolite lattice during ion-exchange with solutions of metal chlorides was directly related to the pH of the solution and that the presence of the metal cation played no part in the dealumination. Our work more closely mirrors that of Bailar and coworkers (14-16) who found that solutions of CrCl3 under reflux conditions could dealuminate a variety of zeolites to a much greater extent than the pH of the CrCl3 solutions would predict. To explain their results, they proposed that the chromium cations could complex with hydrolyzed aluminum ions in the zeolite through the formation of "ol bridges" which then diffused out of the zeolite. Therefore,... 

The recovery of uranium from hydrochloric acid solutions and its concentration are described in [43]. In this operation, 10 M HCl solution containing uranium traces is treated with strongly basic anion exchanger. Upon washing the ion exchanger with water the effluent of uranyl chloride at a concentration level as large as 200 g/L uranium is obtained. 

Catalysts. The starting material for all the catalysts was Linde 13X in powder form, free of clay binder. The bulk sample had a silicon-to-aluminum ratio of 1.27 dz 0.02 16). In all cases, the zeolites were prepared by ion exchange with salt solution (either chloride, sulfate, or nitrate) of the required cation at room temperature. The extent of exchange was estimated from either analysis of the residual salt solution or determination of the residual sodium in the zeolite sample. After preparation, the exchanged zeolites were stored over saturated calcium nitrate solution. 

Monosulfonation of primary and secondary diols can generally be accomplished under controlled conditions. The selective tosylation of diol (54), followed by reaction with trimethylamine in a sealed tube and ion exchange with Dowex-1 (Cl") resin gave (+)-muscarine chloride (55 Scheme 23). ° Intramolecular alkylation of cyclic amine (56) gave quaternary ammonium salt (57) subsequent hydrogenolysis of the benzyl group in (57) afforded (58 Scheme 23). ... 

Maneb Hydrolysis with hydrochloric acid containing stannous chloride Ion-exchange colunon, GC 0.1 mg/kg No data Newsome 1974 in lARC 1996... 

It follows from the proposed mechanism of chloride ion exchange in this system that platinum exchange between the platinum(ii)-platinum(iv) species should proceed at the same rate as does the chloride ion exchange. Another way of observing the same thing would be to start with Pt in one of the complexes and follow the rate at which it is distributed between the two different oxidation states of platinum. These experiments have been done and support the proposed mechanism. 

Fig. 13. Solid-state ion exchange with manganese chloride. Number of bridging OH groups consumed via solid-state exchange in a mixture of MnCl2 and H-ZSM-5 (Si/Al = 13.5, Mn +/OH=0.33) as a function of reaction time at 570, 670 and 770 K Ufter Ref. [14], with permission).

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