Stability organic alkali compounds

The insertion of elemental tellurium into C — Li or C — Na bonds is a convenient method for the preparation of alkali metal tellurolates. Many organic lithium compounds are commercially available or can be prepared, for instance, by halogen-lithium or hydrogen-lithium exchange. The reactions of the organic lithium compounds with elemental tellurium are performed in inert organic solvents such as diethyl other, tetrahydrofuran, tetrahydrofuran/hexane, or diethyl ether/benzene at temperatures (— 196° to + 20°) compatible with the stability of the organic lithium compound. The applicability of this reaction for the synthesis of aliphatic, aromatic, and heteroaromatic lithium tellurolates is documented in Table 1 (p. 155). 

Whereas ionization and dissociation are clearly defined processes on the left side of Scheme 35, the situation is more complicated for carbanionic systems (Scheme 35, right). Organic alkali metal compounds, for example, which often exist as aggregates, are often described as covalent species with a certain percentage of ionic character [140-142]. If the formal carbanion is a resonance-stabilized species (e.g, diphenylmethyl lithium or sodium), the species with the closest interaction between the organic fragment and the metal is usually called a contact ion pair. In... 

Chemical Reactivity - Reactivity with Water No reaction Reactivity with Common Materials May attack some forms of plastics Stability During Transport Stable Neutralizing Agents for Acids and Caustics Not pertinent,- Polymerization Hazardous polymerization unlikely to occur except when in contact with alkali metals or metallo-organic compounds Inhibitor of Polymerization 10 -20 ppm tert-butylcatechol. 

Galli mentioned the addition of alkali-earth metals (mainly calcium) to the BGE to improve separation of organic acids. Calcium ions interact through the formation of complexes with different stabilities giving different mobilities. EDTA may also be used to form different complexes. Alternatively, EDTA may remove interfering compounds. 

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