Alkali lithium

Lithium, rubidium, and caesium.—F. C. Robinson and C. C. Hutchins 7 extracted all three alkalies—lithium, rubidium, and caesium—by decomposing the mineral with fluorspar in the following manner ... 

The smallest alkali, lithium, almost certainly follows magnesium into the smaller Ml site. 

Bases, strong Choline. Claisen s alkali. Lithium (potassium, sodium) amide (ethoxide, hydroxide, methoxide). Lithium nitride. Phenyllithium (potassium, sodium). Potassium r-butoxide. Potassium (sodium) 2-methyl-2-butoxide. Resins Amberlite IRA-dOO. Dowex... 

Alkalis Lithium salts Urea (>3M) Thiol compounds ... 

Simplest examples are prepared by the cyclic oligomerization of ethylene oxide. They act as complexing agents which solubilize alkali metal ions in non-polar solvents, complex alkaline earth cations, transition metal cations and ammonium cations, e.g. 12—crown —4 is specific for the lithium cation. Used in phase-transfer chemistry. ... 

Lithium chemistry Lithium is an alkali metal, electronic configuration ls 2s forming a... 

The table contains vertical groups of elements each member of a group having the same number of electrons in the outermost quantum level. For example, the element immediately before each noble gas, with seven electrons in the outermost quantum level, is always a halogen. The element immediately following a noble gas, with one electron in a new quantum level, is an alkali metal (lithium, sodium, potassium, rubidium, caesium, francium). 

The alkali metals of Group I are found chiefly as the chlorides (in the earth s crust and in sea water), and also as sulphates and carbonates. Lithium occurs as the aluminatesilicate minerals, spodimene and lepidolite. Of the Group II metals (beryllium to barium) beryllium, the rarest, occurs as the aluminatesilicate, beryl-magnesium is found as the carbonate and (with calcium) as the double carbonate dolomite-, calcium, strontium and barium all occur as carbonates, calcium carbonate being very plentiful as limestone. 

As with the hydroxides, we find that whilst the carbonates of most metals are insoluble, those of alkali metals are soluble, so that they provide a good source of the carbonate ion COf in solution the alkali metal carbonates, except that of lithium, are stable to heat. Group II carbonates are generally insoluble in water and less stable to heat, losing carbon dioxide reversibly at high temperatures. 

The properties of lithium resemble those of the alkaline earth metals rather than those of the alkali metals. Discuss this statement. 

Lithium is presently being recovered from brines of Searles Lake, in California, and from those in Nevada. Large deposits of quadramene are found in North Carolina. The metal is produced electrolytically from the fused chloride. Lithium is silvery in appearance, much like Na and K, other members of the alkali metal series. It reacts with water, but not as vigorously as sodium. Lithium imparts a beautiful crimson color to a flame, but when the metal burns strongly, the flame is a dazzling white. 

The amount of metal required gives an indication of the water content. note 3. If the conversion takes longer, add some liquid ammonia to keep the volume of the suspension between 500 and 800 ml. iinte 4. The conversion of lithium and potassium into the alkali amides has never given problems. 

The formation of the above anions ("enolate type) depend on equilibria between the carbon compounds, the base, and the solvent. To ensure a substantial concentration of the anionic synthons in solution the pA" of both the conjugated acid of the base and of the solvent must be higher than the pAT -value of the carbon compound. Alkali hydroxides in water (p/T, 16), alkoxides in the corresponding alcohols (pAT, 20), sodium amide in liquid ammonia (pATj 35), dimsyl sodium in dimethyl sulfoxide (pAT, = 35), sodium hydride, lithium amides, or lithium alkyls in ether or hydrocarbon solvents (pAT, > 40) are common combinations used in synthesis. Sometimes the bases (e.g. methoxides, amides, lithium alkyls) react as nucleophiles, in other words they do not abstract a proton, but their anion undergoes addition and substitution reactions with the carbon compound. If such is the case, sterically hindered bases are employed. A few examples are given below (H.O. House, 1972 I. Kuwajima, 1976). 

The Birch reductions of C C double bonds with alkali metals in liquid ammonia or amines obey other rules than do the catalytic hydrogenations (D. Caine, 1976). In these reactions regio- and stereoselectivities are mainly determined by the stabilities of the intermediate carbanions. If one reduces, for example, the a, -unsaturated decalone below with lithium, a dianion is formed, whereof three different conformations (A), (B), and (C) are conceivable. Conformation (A) is the most stable, because repulsion disfavors the cis-decalin system (B) and in (C) the conjugation of the dianion is interrupted. Thus, protonation yields the trans-decalone system (G. Stork, 1964B). 

Some excited configurations of the lithium atom, involving promotion of only the valence electron, are given in Table 7.4, which also lists the states arising from these configurations. Similar states can easily be derived for other alkali metals. 

Alkali Metal Perchlorates. The anhydrous salts of the Group 1 (lA) or alkah metal perchlorates are isomorphous with one another as well as with ammonium perchlorate. Crystal stmctures have been determined by optical and x-ray methods (38). With the exception of lithium perchlorate, the compounds all exhibit dimorphism when undergoing transitions from rhombic to cubic forms at characteristic temperatures (33,34). Potassium perchlorate [7778-74-7] KCIO, the first such compound discovered, is used in pyrotechnics (qv) and has the highest percentage of oxygen (60.1%). 

Alkali metal peroxides are stable under ambient conditions in the absence of water. They dissolve vigorously in water, forming hydrogen peroxide and the metal hydroxide. They are strong oxidizing agents and can react violendy with organic substances. Only lithium peroxide and sodium peroxide have been commercialized. 

Alkali moderation of supported precious metal catalysts reduces secondary amine formation and generation of ammonia (18). Ammonia in the reaction medium inhibits Rh, but not Ru precious metal catalyst. More secondary amine results from use of more polar protic solvents, CH OH > C2H5OH > Lithium hydroxide is the most effective alkah promoter (19), reducing secondary amine formation and hydrogenolysis. The general order of catalyst procUvity toward secondary amine formation is Pt > Pd Ru > Rh (20). Rhodium s catalyst support contribution to secondary amine formation decreases ia the order carbon > alumina > barium carbonate > barium sulfate > calcium carbonate. 

Ring Additions Catalyzed by Alkali Metals. The addition of tributyltin chloride and olefins such as styrene, isoprene, or butadiene to sulfolane is cataly2ed by alkah metals, including sodium and lithium, and by sodium amide (10—13). The addition of tributyltin chloride to sulfolane in the... 

Metallic Antimonides. Numerous binary compounds of antimony with metallic elements are known. The most important of these are indium antimonide [1312-41 -0] InSb, gallium antimonide [12064-03-8] GaSb, and aluminum antimonide [25152-52-7] AlSb, which find extensive use as semiconductors. The alkali metal antimonides, such as lithium antimonide [12057-30-6] and sodium antimonide [12058-86-5] do not consist of simple ions. Rather, there is appreciable covalent bonding between the alkali metal and the Sb as well as between pairs of Na atoms. These compounds are useful for the preparation of organoantimony compounds, such as trimethylstibine [594-10-5] (CH2)2Sb, by reaction with an organohalogen compound. 

A number of compounds of the types RBiY2 or R2BiY, where Y is an anionic group other than halogen, have been prepared by the reaction of a dihalo- or halobismuthine with a lithium, sodium, potassium, ammonium, silver, or lead alkoxide (120,121), amide (122,123), a2ide (124,125), carboxylate (121,126), cyanide (125,127), dithiocarbamate (128,129), mercaptide (130,131), nitrate (108), phenoxide (120), selenocyanate (125), silanolate (132), thiocyanate (125,127), or xanthate (133). Dialkyl- and diaryUialobismuthines can also be readily converted to secondary bismuthides by treatment with an alkali metal (50,105,134) ... 

Alkali Metal Catalysts. The polymerization of isoprene with sodium metal was reported in 1911 (49,50). In hydrocarbon solvent or bulk, the polymerization of isoprene with alkaU metals occurs heterogeneously, whereas in highly polar solvents the polymerization is homogeneous (51—53). Of the alkah metals, only lithium in bulk or hydrocarbon solvent gives over 90% cis-1,4 microstmcture. Sodium or potassium metals in / -heptane give no cis-1,4 microstmcture, and 48—58 mol % /ram-1,4, 35—42% 3,4, and 7—10% 1,2 microstmcture (46). Alkali metals in benzene or tetrahydrofuran with crown ethers form solutions that readily polymerize isoprene however, the 1,4 content of the polyisoprene is low (54). For example, the polyisoprene formed with sodium metal and dicyclohexyl-18-crown-6 (crown ether) in benzene at 10°C contains 32% 1,4-, 44% 3,4-, and 24% 1,2-isoprene units (54). 

N-Alkylations, especially of oxo-di- and tetra-hydro derivatives, e.g. (28)->(29), have been carried out readily using a variety of reagents such as (usual) alkyl halide/alkali, alkyl sulfate/alkali, alkyl halide, tosylate or sulfate/NaH, trialkyloxonium fluoroborate and other Meerwein-type reagents, alcohols/DCCI, diazoalkanes, alkyl carbonates, oxalates or malon-ates, oxosulfonium ylides, DMF dimethyl acetal, and triethyl orthoformate/AcjO. Also used have been alkyl halide/lithium diisopropylamide and in one case benzyl chloride on the thallium derivative. In neutral conditions 8-alkylation is observed and preparation of some 8-nucleosides has also been reported (78JOC828, 77JOC997, 72JOC3975, 72JOC3980). 

In some cases, especially in the presence of strongly electron attracting substituents, isomerization to acid amides has been observed, probably preceded by deprotonation at ring carbon. Even (56), known for its stability towards common alkali, undergoes this rearrangement when a lithium amide is used as the base (80JOC1489). 

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