Anion attachment

These will be represented by (Res.A )B , where Res. is the basic polymer of the resin, A is the anion attached to the polymeric framework, B+ is the active or mobile cation thus a sulphonated polystyrene resin in the hydrogen form would be written as (Res.SO J)H. A similar nomenclature will be employed for anion exchange resins, e.g. (Res. NMeJ )CI . 

Jiang, Y. and Cole, R.B. (2005) Oligosaccharide analysis using anion attachment in negative mode electrospray mass spectrometry. J. Am. Soc. Mass Spectrom., 16 (1), 60-70. 

Radical anions are not often observed. Fullerene [20] has no hydrogen atom in it, and thus ionization can only occur through electron capture or anion attachment. Figure 7.14 displays its spectrum obtained under negative ion desorption chemical ionization conditions with a CH4-N2O mixture as the ionizing gas [21],... 

Clusters of approximately D3 symmetry containing 30 niobium centers have been reported. These consist of five [NbeOi9] anions attached in trigonal bipyramidal fashion to a central oxocluster containing two AP+ and six Ln + (Ln = Eu, Er, Lu) cations. 

Figure 5.13. Reactions involved in cationic addition polymerization. Shown are (a) generation of a carbo-cation intermediate from a Lewis acid initiator, (b) propagation of the polymer chain through the combination of the carbocationic polymer chain and additional monomers, and (c) termination of the polymer growth through either proton abstraction (i) or anionic attachment (ii) routes.

Ionize (anion) Attach electron(s) to the gaseous nonmetal atom to form the gaseous anion. Several electron affinity values may be required. Recall that for electron gain, A//= - ea for each electron added. 

Under Cl conditions, negative reagent ions are also formed (Table 1) and these can effect analyte ionization by hydride abstraction (Equation (9)) or anion attachment (Equation (10)) (Figure 3(e)). 

The electrochemistry of organic anions attached to zeolites can be described in terms of oxidation steps involving the issue of metal cations and reduction steps involving the ingress of electrolyte cations into the zeolite pore/channel system (Domenech et al., 2005a). 

The synthetic strategies for the esters of cephalotaxine follow, for the most part, the partial esterification method, lire ideas that are exploited in the access to the fragments vary, but most use as the last step the anionic attachment of the acetate portion. The one method that remains to be exploited here is the enzymatic esterification of the natural enantiomer of cephalotaxine either with a racemate of the complete side chain (kinetic resolution) or with the appropriate enantiomer of the ester side chain. It is hoped that the solution to this particular problem in either enzymatic catalysis or plant tissue culture preparation will materialize in the near future. 

The C1F bond length and C1FF bond angle found in C1F2+ ion depends on the nature of the anion attached to this cation. 

The incorporation of lanthanum and zirconium causes a strong decrease of the reducibility of the surface capping oxygen anions attached to surface Ce+ in the... 

Chelation occurs when the electron-donating nitrogen and the acetic anion attaches to the metal ion (e.g., Cu2+), to form a cyclic ring (Figure 4.5). 

In an APCI interface the column effluent enters a heated nebulizer where the pneumatically assisted desolvation process is almost completed. While still in the spray chamber, ionization of analytes is initiated by corona discharge. The ionization mechanisms in APCI are almost identical to those in conventional medium pressure chemical ionization (7). Positive ion formation can be achieved by proton transfer, adduct formation or charge exchange reactions, while in the negative mode ions are formed due to proton abstraction, anion attachment and electron capture reactions. The APCI interface is compatible with flow rates exceeding 1 ml/min and will... 

There have been many approaches published to "immobilize" a homogeneous catalyst. These heterogeneous catalysts must have better activity, selectivity, lifetime or some other property to warrant their use in an industrial chemical process. This talk will draw upon the author s experiences at DuPont and Air Products with Nation , Nafion on carbon, anionic attached [Rh(CO)2l2] to Reillex-425, carbons as catalysts for the hydrolysis of esters, heterogeneous catalyst to activate dimethyl ether as a methyl transfer reagent, and monoliths as hydrogenation catalysts. These individual experiences will show the complexities of a simple problem - "immobilization". 

Anions attached on anion exchange resins can be replaced by other anions (OH, COj , SO4, Cr,etc.)... 

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