Lithium solution

It is advisable to filter the a-picolyl-lithium solution rapidly through a thin layer of glass wool (to remove any unreacted lithium) on to the solid carbon dioxide. 

The function of the trap is to condense the hexane from the n-butyl-lithium solution. The checkers used a 1-L three-necked flask fitted with a short delivery tube (a quick fit air bleed tube was used), stopper, and rubber tubing connection. The submitters used a water aspirator and a 1-L filter flask with a drying tower between. 

IQ. To determine the concentration of chloride ion, - a 5-mL aliquot of the methyl lithium solution is cautiously added to 25 ml of water and the resulting solution is acidified with concentrated sulfuric acid and then treated with 2-3 ml of ferric ammonium sulfate [Fe(NH4)( 04)2 12 H2O] indicator solution and 2-3 ml of benzyl alcohol. The resulting mixture is treated with 10.0 mL of standard aqueous 0.100 M silver nitrate solution and then titrated with standard aqueous 0.100 H potassium thiocyanate solution to a brownish-red endpoint. 

The quality of phenyl-lithium used to generate ylides can have a pronounced effect on the stereochemistry of olefin synthesis. In the reactions of the ylide (36) with the aldehydes (37) c/5-olefins were obtained using a phenyl-lithium solution containing one equivalent of total base while /m/ij-olefins resulted from the use of an amount of this solution containing one equivalent of genuine phenyl-lithium together with six equivalents of other, unspecified, base. ... 

Lithium has been found to prevent ASR expansion [37]. It is used either to mitigate further distress in ASR-affected structures by topical application of lithium solutions or as a means of using ASR aggregates in new structures when other methods of ASR mitigation are not feasible. As a critical amount of lithium is needed in the pore solution of cement paste to arrest the expansion [38], a method to spatially resolve and quantify the lithium is desirable. 

We found, however, that even highly concentrated lithium (9M) or sodium (3M) solutions did not reduce coal in a manner that increased its hydroxyl content and in parallel tests, 100% unreacted p-phenoxy phenol was always recovered from the lithium solutions ... 

Kawata, H. (1979) Conttactility of the frog ventricular myocardium in sodium-free lithium solution./p / Physiol 29 609-625. 

Another complication introduced by the associative properties of organolithium solutions in non-polar solvents is the fact that the alkyllithium initiators are themselves associated and can be expected to "cross associate" with the active polymer chain ends. Thus some of our studies (26) on the effect of added ethyl lithium on the viscosity o -polyisoprenyl lithium solutions in n-hexane support the following association equilibrium... 

Alternatively, the butyl lithium solution may be forced into the reaction flask by means of an 18 gauge cannula Inserted through the serum cap. 

The phenyl lithium solution was purchased from Aldrich Chemical Company, Inc. The checkers used 64 mL (0.115 mol) of 1.8 M phenyllithium in 75 25 benzene-ether which was purchased from Alpha Products, Morton/Thiokol Inc. 

Radioactivation analysis has been used to measure bromine in polymers (37—39) and recently a novel technique for trace oxygen has been reported (40). Any polymer or other material (e.g. metal alkyl) which is miscible with butyl lithium solutions may be analysed since the procedure involves the intermediate production of triton particles by the nuclear reaction 6Li (n, a) t. The tritons then act as nuclear projectiles for the activation of oxygen 0 (t, n) 18F and the radioactivity due to fluorine-18 is measured. A sensitivity of 1 x 10 g in a 0.5 g sample is claimed. 

This salt can be prepared in essentially quantitative yield by the careful addition of a butyl-lithium solution in hexanes to a stirred solution of pentamethylcyclopentadiene in dry pentane under N2. After 5 h of stirring at room temperature, the resulting white precipitate is filtered, washed with pentane, and dried under vacuum. 

They observed that, when a solution of lithium in tritiated ammonia was mixed with a solution of ammonium bromide in ordinary ammonia, the evolved hydrogen contained much less tritium than when a solution of lithium in ordinary ammonia was mixed with a solution of ammonium bromide in tritiated ammonia. These results were taken as evidence that the NH4+ + e reaction is an order of magnitude faster than the NH4 + + NH3 reaction. However when one considers that electrons in ammonia have an abnormally high mobility, and that they probably migrate without carrying ammonia molecules with them (11, 23), this interpretation seems doubtful. It is possible that the electrons diffused into the ammonium bromide solutions much more rapidly than the ammonium ions diffused into the lithium solutions, and that consequently the evolved hydrogen was always characteristic of the ammonium bromide solutions. Thus these experiments yield little information about the relative rates of the NH4+ + e reaction and NH4+ + NH3 reaction. 

Furthermore, several of Worsfold s assessments seem to be open to question. The assertion that the association (between the allylic-lithium active centers) is between ionic species can be contrasted with the evidence provided by NMR spectroscopy 36,134 143) which has shown that the carbon-lithium bond of allylic-lithium species can possess considerable covalent character. Worsfold has also previously published 43 > concentrated solution viscosity results where the ratio of flow times, before and after termination, of a poly(isoprenyl)lithium solution was about 15. This finding is clearly incompatible with the conclusion that viscometry cannot detect the presence of aggregates greater than dimeric. 

Butyl lithium was being used in a glove box, a spillage was cleaned up with paper towels later removed and treated with water. A towel which reached a waste bin unwetted later ignited starting a small fire [1], (It is the editor s experience that butyl lithium solutions falling on cellulose in air ignite more often than not destroy alkylhthiums first, mop up later.)... 

The halide solution is then cooled to — 78°C., and the methyl-lithium solution is added slowly over a one-hour period with... 

Bis[benzo-1 -thiophen-2-yltelluro]methane5 In a 250 ml, nitrogen-flushed flask fitted with a stirrer are placed 2.1 g (15.7 mmol) of benzothiophene and 50 ml of tetrahydrofuran. 6.5 ml (15 mmol) of n-butyl lithium solution are added to the stirred benzothiophene solution at 20°, stirring is continued for 1 h, and then 1.9 g (14.9 mmol) of tellurium are added. The mixture is stirred until all the tellurium has been consumed (1 h), then 40 ml of dry dichloromethane are added to the stirred mixture and stirring at 20° is continued overnight. The mixture is poured into 200 ml of water, the organic layer is separated, the aqueous layer is extracted with further dichloromethane, and the combined dichloromethane solutions arc dried with anhydrous calcium chloride, filtered, and evaporated. The residue is recrystallized from acetonitrile yield 2.7 g (68%) m.p. 127°. 

As soon as the receiver containing the methyl lithium solution has been removed and stoppered, the residual solids in the reaction flask and the filtration apparatus should be rinsed into another receiver with anhydrous ether under an atmosphere of argon or nitrogen. The ether slurry of solids, which may contain some unchanged lithium metal, should be treated cautiously in a hood with t-butyl alcohol to consume any residual lithium metal before the mixture 1s discarded. 

By means of the double-tipped steel cannula add 100 mL of the p-anisyl-lithium solution to the suspension at room temperature. At the beginning of addition, the temperature rises to 40°C and a bright-yellow colour appears in the flask. This yellow colour disappears progressively and at the end of the addition (100 mL, 130 mmol p-anisyllithium) a dark-red solution is obtained. Stir under argon at room temperature for a further 48 h. 

Standard Lithium Solutions. Dissolve 4.3516g of lithium chloride monohydrate in sufficient O.IM hydrochloric acid to produce 100 ml. This solution contains 5 mg of Li in 1 ml. Serially dilute the solution widi sodium chloride-potassium chloride solution to produce solutions containing 5.0, 10.0, 15.0, 20.0, and 25.0 LLg of Li in 1 ml. 

These design features eliminate almost all pathways to a serious accident, but elimination of the lithium chemical energy would be even better. Hence, the ideal DT fusion reactor would utilize lithium that is combined with other elements to produce a fluid that is not reactive with air or water, but still retains the low density and high heat capacity of pure lithium. Various lead-lithium solutions have been considered, but none fully satisfy these criteria. 

Hoffman, N. J. Blink, J. A. Darnell, A. "Properties of Lead-Lithium Solutions" Proc. 4th ANS Top. Mtg. Tech, of Controlled Nucl. Fusion King of Prussia, PA, 1980. 

For most purposes it is reasonable to assume quantitative formation of LDA using this method, consequently if the i butyl lithium solution has been accurately titrated, the amount of LDA formed should be known, however if problems are encountered there are procedures available to check the titre of the LDA itself.5... 

Fig. 14. Absorbance-concentration curves obtained with aqueous lithium solutions. Note the difference in sensitivities depending on the type of line source (from reference (M3) by courtesy Perkin-Elmer Corporation).

Lithium Benzenetellurolate Into a 250-m/, nitrogen-flushed, three-necked flask equipped with a magnetic stirrer, a reflux condenser, a nitrogen inlet tube, and a dropping funnel are placed 30 ml of anhydrous diethyl ether and 0.14 g (0.02 mol) of lithium. To the lithium suspension are added dropwise 3.14 g (0.02 mol) of bromobenzene at a rate sufiicient to keep the ether boiling gently. The mixture is heated under reflux with stirring until all of the lithium has reacted (about 1 h). Then 2.56 g (0.02 mol) of tellurium suspended in 50 ml of diethyl ether are added over 1 h to the phenyl lithium solution. The mixture is then stirred for 1 h at 20" and for 1 h under reflux. 

Tetraphenyl tellurium was similarly obtained in 34% yield from triphenyl telluronium iodide and phenyl lithium . Solutions of tetramethyl tellurium were prepared from trimethyl telluronium iodide and methyl lithium. The formation of butyl triphenyl tellurium was claimed in a reaction of triphenyl telluronium iodide and butyl lithium. Equimolar amounts of triphenyl telluronium chloride and 3,3-bis[chloromercuro]-2,4-pentadione in refluxing methanol produced 3-[chloromercuro]-2,4-dioxopent-3-yl triphenyl tellurium. ... 

MethylphenotcIIurazine 5,5-Dichloride Under nitrogen, 3.7 ml (6.3 mmol) of a 1.7 molar butyl lithium solution are added dropwise to a solution of 1.0 g (2.9 mmol) of bis[2-bromophenyl]methylamine in 35 ml of dry tetrahydrofuran at 0°. The mixture is stirred at 0° for 1 h, 0.79 g (2.9 mmol) of tellurium tetrachloride in 10 m/of dry tetrahydrofuran are added dropwise to the solution of bis[2-lithiophenyl]methylamine, and the mixture is stirred for 2 h. The solvent is then evaporated, the residue is dissolved in 250 ml of dichloromethane, and the solution is washed with water, dried, and evaporated. The yellow solid is recrystallized from acetonitrile yield 0.2 g (18%) m.p. > 270". 

During the first half of the addition each drop of methyl-lithium solution produces a yellow color that quickly disappears. The solution turns yellow during the second half of the addition and slowly becomes more intensely colored until it reaches red-orange near the end of the reaction period. 

Synthesis of cyantrimethylsilylamides from alkali metal alkyls. A methyl lithium solution (25 mL, 1.6 mol, FLUKA) or n-buthyl lithium (8 mL, 2.5 mol, CHEMETALL) in diethylether or toluene were slowly added to a mixture of 10 mL BTSC and 15 mL n-hexane at 0 °C. A white precipitate formed which was purified as described above. 

The methyl lithium solution was obtained from MetalIgeselischaft, Frankfurt. The checkers used methyl lithium (Aldrich Chemical Company, Inc.), salt free 1.4 M in ethyl ether, with no significant difference observed in the reaction. 

---