Lithium ion, complexing with

However, a recent study of the lithium ion complexation with N-labelled polyphosphazenes, including N-MEEP, was performed by Luther [600]. The data obtained for the MEEP/LiSOjCFj system by NMR, IR and Raman spectroscopies do not support that assumption, and show that the coordination of the lithium ion also occurs with the nitrogen nuclei. 

Changes in the chemical shifts in the and NMR spectra of MEEP following lithium ion addition are consistent with lithium ion complexation with the etherial oxygen nuclei or the nitrogen nuclei of the polyphosphazene backbone. The sharp decrease in the NMR Timin value measured for N MEEP reveals that significant lithium ion complexation preferentially occurs with the nitrogen nuclei rather than the oxygen nuclei. 

Adding reductive additives to the PC can lead to formation of a good SEI film before PC decomposition, which may reduce the PC decomposition on the graphite surface. For example, 2-acetoxy-4,4-dimethyl-Y-butyrolactone forms strong complexes with lithium ions and so diminishes the amount of lithium ions complexed with PC. An acetyl or carbonate group at the 2-position of butyrolactone has been shown to inhibit the decomposition of PC on graphite. 

PAYNE, D.R. and WEIGHT, P.V., 1982. Morphology and ionic conductivity of some lithium ion complexes with poly(ethylene oxide). Polymer, 23(5), 690-693. 

Some instances of incomplete debromination of 5,6-dibromo compounds may be due to the presence of 5j5,6a-isomer of wrong stereochemistry for anti-coplanar elimination. The higher temperature afforded by replacing acetone with refluxing cyclohexanone has proved advantageous in some cases. There is evidence that both the zinc and lithium aluminum hydride reductions of vicinal dihalides also proceed faster with diaxial isomers (ref. 266, cf. ref. 215, p. 136, ref. 265). The chromous reduction of vicinal dihalides appears to involve free radical intermediates produced by one electron transfer, and is not stereospecific but favors tra 5-elimination in the case of vic-di-bromides. Chromous ion complexed with ethylene diamine is more reactive than the uncomplexed ion in reduction of -substituted halides and epoxides to olefins. ... 

Interaction of atoms and ions with two electrons Ground state of the lithium ion-helium, lithium ion-lithium ion complexes at small inter-nuclear distances. " ... 

In dithioacetals the proton geminal to the sulfur atoms can be abstracted at low temperature with bases such as Bu"Li. Lithium ion complexing bases such as DABCO, HMPA and TMEDA enhance the process. The resulting anion is a masked acyl carbanion, which enables an assortment of synthetic sequences to be realized via reaction with electrophiles. Thus, a dithioacetal derived from an aldehyde can be further functionalized at the aldehyde carbon with an alkyl halide, followed by thioacetal cleavage to produce a ketone. Dithiane carbanions allow the assemblage of polyfunctional systems in ways complementary to traditional synthetic routes. For instance, the p-hydtoxy ketone systems, conventionally obtained by an aldol process, can now be constructed from different sets of carbon groups. ... 

With the intention of achieving much higher selectivity for lithium ion complexation, a spherand type host 5 containing a dinitrophenylazophenol moiety was designed and synthesized by the use of a key step, photodeselenation which we developed previously (Scheme 1) [5]. 

Fig. 5 Sequence dependence of the ability of an alkali cation to stabilize the salt bridge, (a) Structures of the most stable zwitterion form for the lithium ion complexes (b) IRMPD spectra of the complexes. Arg at the C-terminus favors salt bridging, while the reverse sequence (in combination with a small ion such as Li" or Na" ) can give a stable CS ion as signaled by the strong peak near 1,750 cm of the ArgGly complexes of those ions. Reproduced with permission from [102]...

Spectroscopy in the hydrogen-stretching region was applied to characterize proton and lithium-ion complexed valine complexes as a function of hydration with up to four water molecules [22], Although calculations and prior study by black-body infrared dissociation had suggested the possibility of zwitterions,... 

In the remainder of this chapter, particular reactions are selected for examination of their synthetic potential. Acetylide ions are useful for linking carhon chains, particularly where a double bond is desired with stereoselectivity. Acetylene and 1-alkynes may be deprotonated with strong bases such as LDA and then treated with alkyl halides or carbonyl compounds. Preformed lithium acetylide complexed with ethylenediamine is available as a dry powder. Several alkynes derived from acetylide and carbon dioxide or formaldehyde are available, including propargyl alcohol (HC CCHjOH), propargyl bromide (HC CCH Br), and methyl propio-late (HC=CC02CH3). 

Ferrocene and its derivatives have an oxidation potential of 3.0-3.5 V (vs. Li+/Li), which will cause the battery to terminate the charge process before completion. The complexes of Fe + ion with 2,2 -bipyridine and 1,10-phenanthroline have an oxidation potential that is about 0.7 V higher, so that the termination voltage can be about 3.S-3.9 V. However, this is still not useful for lithium-ion batteries with an output voltage > 4 V as overcharge protection additives. 

Poly(ethylene oxide) associates in solution with certain electrolytes (48—52). For example, high molecular weight species of poly(ethylene oxide) readily dissolve in methanol that contains 0.5 wt % KI, although the resin does not remain in methanol solution at room temperature. This salting-in effect has been attributed to ion binding, which prevents coagulation in the nonsolvent. Complexes with electrolytes, in particular lithium salts, have received widespread attention on account of the potential for using these materials in a polymeric battery. The performance of soHd electrolytes based on poly(ethylene oxide) in terms of ion transport and conductivity has been discussed (53—58). The use of complexes of poly(ethylene oxide) in analytical chemistry has also been reviewed (59). 

Ethylenediamine tetraacetic acid (EDTA) [60-00-4] (Sequestrene), an anticoagulent at 1 mg of the disodium salt per mL blood, complexes with and removes calcium, Ca ", from the blood. Oxalate, citrate, and fluoride ions form insoluble salts with Ca " and chelate calcium from the blood. Salts containing these anticoagulants include lithium oxalate [553-91-3] 1 mg/mL blood sodium oxalate [62-76-0]2 mg/mL blood ... 

Most other studies have indicated considerably more complex behavior. The rate data for reaction of 3-methyl-l-phenylbutanone with 5-butyllithium or n-butyllithium in cyclohexane can be fit to a mechanism involving product formation both through a complex of the ketone with alkyllithium aggregate and by reaction with dissociated alkyllithium. Evidence for the initial formation of a complex can be observed in the form of a shift in the carbonyl absorption band in the IR spectrum. Complex formation presumably involves a Lewis acid-Lewis base interaction between the carbonyl oxygen and lithium ions in the alkyllithium cluster. 

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