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Alkyl lithium compounds are either low melting solids or liquids, and often with high volatility (depending on the substituent) due to the covalent nature of the bonding. They are soluble in aliphatics, aromatics, and ethers. However, while the reaction with ethers is generally slow, [link] , alkyl lithium compounds can polymerize tetrahydrofuran (THF).

Organolithium compounds react rapidly with air and water (both vapor and liquid). The reaction with water is the basis of the Gillman double titration method for determining the concentration of organolithium reagents in solution.


The structure of organolithium compounds is dominated by their highly oligomeric nature as a result of 3-center 2-electron bridging bonds. In all cases the extent of oligomerization is dependant on the identity of the alkyl (or aryl) group. The alkyl-bridged bond is similar to those found for beryllium and aluminum compounds.

In the vapor phase any particular organolithium derivative show a range of oligomeric structures. For example, the mass spectrum of EtLi shows ions associated with both tetramers (e.g., [Et 3 Li 4 ] + ) and hexamers (e.g., [Et 5 Li 6 ] + ). The structures of the different oligomers have been predicted by molecular orbital calculations ( [link] ).

Proposed vapor phase structures for various oligomers of RLi.

Solution molecular weight measurements indicate the oligomerization is present (in the absence of a coordinating ligand such as Et 2 O or an amine). The extent of oligomerization depends on the steric bulk of the alkyl group ( [link] ). Oligomerization and solution structures have also been investigated by 7 Li and 13 C NMR spectroscopy.

Extent of oligomerization (n) for organolithium compounds [RLi] n in benzene solution.
R [RLi] n R [RLi] n
Me 4 Et 6
n Bu 6 t Bu 4

There are a large number of X-ray crystallographically determined structures for organolithium derivatives. The archetypal example is MeLi, which exists as a tetramer in the solid state ( [link] ). The lithium atoms are arranged as a tetrahedron and the carbon atoms are positioned on the center of the facial planes, i.e., the carbon is equidistant from each of the lithium atoms. In contrast, EtLi has a similar tetrahedral structure, but the α-carbon of the ethyl groups are asymmetrically arranged such that it is closer to one lithium atom than the other two.

Solid state structure of MeLi. Copyright: Ben Mills (2007).

It is possible to prepare monomeric organolithium compounds by the addition of amines, especially chelate ligands such as ethylenediamine (en) and tetramethylethylenediamine (TMED). The reactivity of RLi is increased dramatically by the addition of such Lewis bases. For example, PhCH 2 Li shows an increased reactivity of 10 4 with the addition of TMED.

The bonding in organolithium compounds is difficult to describe:

  • Based upon the relative electronegativity of Li (0.98) and C (2.5) it would be expected to have significant ionic character.
  • Organolithium compounds form electron deficient oligomers typical of covalent bonding and clearly not as a result of ionic aggregation.
  • The spin-spin coupling, J (C-Li), observed by NMR spectroscopy (10 – 15 Hz) are consistent with a covalent bond.
  • Organolithium compounds undergo radical reactions.

However, the overall description of the bonding in RLi is that of a covalent interaction with significant polar (ionic) character, i.e., M δ + -C δ - .

The use of organolithium compounds in organic synthesis

Organolithium compounds perform many of the reactions commonly observed for Grignard reagents. However, lithium reagents are generally more reactive than their Grignard analogs.


Organolithium compounds react with water to give the hydrocarbon and lithium hydroxide, [link] . Lithium alkyls also react with other hydroxylic compounds such as alcohols and carboxylic acids, [link] .

One important use of the hydrolysis reaction is specifically deuteration, [link] .

Reaction with carbonyls

Organolithium compounds react with organic carbonyls (aldehydes, ketones, and esters) to yield the alcohol on hydrolysis, [link] . This synthetic route is particularly useful since lithium reagents are far more reactive than the analogous Grignard, allowing reactions to be carried out at lower temperatures and minimizing enolization side reactions.

The high reactivity of alkyl lithium compounds means that they react with carboxylic acids to yield the ketone rather than the lithium carboxylate.

Organolithium compounds generally react with α,β-unsaturated ketones to give the 1,2-addition product, [link] . However, lithium dialkylcuprates, which are formed from the alkyl lithium and copper(I) iodide, [link] , add exclusively by the 1,4-addition, [link] .


One of the most useful methods of preparing organometallic compounds is the exchange reaction of one organometallic compound with a salt of a different metal, [link] . This is an equilibrium process, whose equilibrium constant is defined by the reduction potential of both metals. In general the reaction will proceed so that the more electropositive metal will form the more ionic salt (usually chloride).

Lithium reagents may be used to prepare a wide range of organometallic compounds.


  • G. Graham, S. Richtsmeier, D. A. Dixon. J. Am. Chem. Soc. , 1980, 102 , 5759.
  • E. Weiss, E. A. C. Lucken, J. Organomet. Chem., 1964, 2 , 197.
  • H. O. House, Acc. Chem. Res., 1976, 9 , 59.

Questions & Answers

What is price elasticity of demand and its degrees. also explain factors determing price elasticity of demand?
Yutansh Reply
Price elasticity of demand (PED) is use to measure the degree of responsiveness of Quantity demanded for a given change on price of the good itself, certis paribus. The formula for PED = percentage change in quantity demanded/ percentage change in price of good A
its is necessarily negative due to the inverse relationship between price and Quantity demanded. since PED carries a negative sign most of the time, we will usually the absolute value of PED by dropping the negative sign.
PED > 1 means that the demand of the good is price elasticity and for a given increase in price there will be a more then proportionate decrease in quantity demanded.
PED < 1 means that the demand of the good is price inelasticity and for a given increase in price there will be a less then proportionate decrease in quantity demanded.
The factors that affects PES are: Avaliablilty of close substitutes, proportion of income spent on the good, Degree of necessity, Addiction and Time.
Calculate price elasticity of demand and comment on the shape of the demand curve of a good ,when its price rises by 20 percentage, quantity demanded falls from 150 units to 120 units.
Helen Reply
5 %fall in price of good x leads to a 10 % rise in its quantity demanded. A 20 % rise in price of good y leads to do a 10 % fall in its quantity demanded. calculate price elasticity of demand of good x and good y. Out of the two goods which one is more elastic.
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Sosna Reply
consider two goods X and Y. When the price of Y changes from 10 to 20. The quantity demanded of X changes from 40 to 35. Calculate cross elasticity of demand for X.
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consider two goods X and Y. When the price of Y changes from 10 to 20. The quantity demanded of X changes from 40 to 35. Calculate cross elasticity of demand for X.
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n a perfectly competitive market, price equals marginal cost and firms earn an economic profit of zero. In a monopoly, the price is set above marginal cost and the firm earns a positive economic profit. Perfect competition produces an equilibrium in which the price and quantity of a good is economic
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 Supply represents how much the market can offer.
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what is Economic
economics is how individuals bussiness and governments make the best decisions to get what they want and how these choices interact in the market
Economics as a social science, which studies human behaviour as a relationship between ends and scarce means, which have alternative uses.
Economics is a science which study human behaviour as a relationship between ends and scarce means
Economics is a social sciences which studies human behavior as a relationship between ends and scarce mean, which have alternative uses.....
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Source:  OpenStax, Chemistry of the main group elements. OpenStax CNX. Aug 20, 2010 Download for free at http://cnx.org/content/col11124/1.25
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