A Anionic

S. Boileau, ia J. E. McGrath, A., Anionic Polymeri tion, ACS Symposium Series 166, American Chemical Society, Washington, D.C., 1981. 

W. M. Linfield, A., Anionic Sufactants Sufactant Science Series, Vol. 7, Marcel Dekker, Inc., New York, 1976. 

C Cation transfer membrane A Anion transfer membrane... 

C — Cation Selective Membrane A — Anion Selective Membrane... 

D-Methylmalonyl-CoA, the product of this reaction, is converted to the L-isomer by methylmalonyl-CoA epunerase (Figure 24.19). (This enzyme has often and incorrectly been called methylmalonyl-CoA racemase. It is not a racemase because the CoA moiety contains five other asymmetric centers.) The epimerase reaction also appears to involve a carbanion at the a-position (Figure 24.20). The reaction is readily reversible and involves a reversible dissociation of the acidic a-proton. The L-isomer is the substrate for methylmalonyl-CoA mutase. Methylmalonyl-CoA epimerase is an impressive catalyst. The for the proton that must dissociate to initiate this reaction is approximately 21 If binding of a proton to the a-anion is diffusion-limited, with = 10 M sec then the initial proton dissociation must be rate-limiting, and the rate constant must be... 

Figure 7. Current-potential curve of a bipolar membrane of hydrous ironflll) oxide in chloride solution. FeCl3(aq)/Fe(HI)(oxideyNaCl(aq)-Na2Mo04(aq).l The system is kept at room temperature. C, cation A, anion. (Reproduced bom M. Sakashita and N. Sato, Corrosion 35,351,1979, Fig. 4 with permission from NACE International.)...

In equilibrium dialysis of a solution of a polyanion (valence Zp negative) with molar concentration Cp against a solution of imi-imivalent electrolyte CA (C = cation, A = anion) with molar concentration Cqa it was shown that the requirement for equal chemical potentials of the salt in the polyanion (a) and diffusate ()) phases results in the following relation... 

In THF at -20°C the N-trimethylsilylated 2-pyrrolidinone 388 is converted by LDA into the a-anion which, on reaction with 1949 and subsequent acidification with AcOH, gives 43% 3-hydroxy-2-pyrrolidinone 1962 [150]. Lithium enolates of ketones such as camphor react with BTSP 1949 to give >95% of a mixture of exo-and mdo-2-hydroxycamphor [151]. Lithiated methyl heterocycles such as lithiated 2-methylpyridine 1963 are converted into mixtures of the 0-SiMe3 1964 and C-SiMe3 1965 compounds and C-methylated compounds such 1966 [152]. 2-Lithioto-luene 1967 is oxidized by 1949 into 1968 [140, 145] (Scheme 12.42). 

Ligand A anionic (e.g., halides, pseudohalides, alkyl, aryl, thiolate, alkoxide) ligand N neutral (e.g., amines, imines, phosphines, carbenes, nitriles, isonitriles, NO, CO) ligand C cationic (e.g., NO+)... 

Gale, P. A. Anion receptor chemistry highlights from 1999. Coord. Chem. Rev. 2001, 213, 79-128. 

Figure 9.4. Schematic representation of carrier-mediated metal-ion transport through a liquid membrane (A = anion).

Some key reactions relevant to this section were not covered in CHEC-II(1996) <1996CHEC-II(4)179>, and hence some references to important work prior to the appearance of CHEC-IK1996) are included. Nonetheless, CHEC-11(1996) does contain many pertinent reactions of ring carbon substituents, such as important information on Curtius rearrangements and a-anion formation and reactivity. 

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