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Tert-butyllithium

tert-Butyllithium
TBuLitetramer.svg
Skeletal formula of tert-butyllithium with all implicit hydrogens shown, and partial charges added
Names
Preferred IUPAC name
tert-Butyllithium
Identifiers
594-19-4 YesY
3D model (Jmol) Interactive image
3587204
ChemSpider 10254347 YesY
ECHA InfoCard 100.008.939
EC Number 209-831-5
PubChem 638178
UN number 3394
Properties
LiC
4H
9
Molar mass 64.055 g mol−1
Appearance Colorless solid
Density 660 mg cm−3
Boiling point 36 to 40 °C (97 to 104 °F; 309 to 313 K)
Reacts
Acidity (pKa) 45–53
Hazards
GHS pictograms The flame pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) The corrosion pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) The exclamation-mark pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) The health hazard pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) The environment pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS)
GHS signal word DANGER
H225, H250, H260, H304, H314, H336, H411
P210, P222, P223, P231+232, P370+378, P422
Extremely Flammable F+ Corrosive C Dangerous for the Environment (Nature) N Very Toxic T+
R-phrases R11, R15, R17, R34, R50/53, R65, R66, R67, R50/53, R38
S-phrases S26, S36/37/39, S43, S45, S62, S61, S16, S33
NFPA 704
Flammability code 4: Will rapidly or completely vaporize at normal atmospheric pressure and temperature, or is readily dispersed in air and will burn readily. Flash point below 23 °C (73 °F). E.g., propane Health code 4: Very short exposure could cause death or major residual injury. E.g., VX gas Reactivity code 4: Readily capable of detonation or explosive decomposition at normal temperatures and pressures. E.g., nitroglycerin Special hazard W: Reacts with water in an unusual or dangerous manner. E.g., cesium, sodiumNFPA 704 four-colored diamond
Flash point −6.6 °C (20.1 °F; 266.5 K)
Related compounds
Related compounds
 n-Butyllithium

sec-Butyllithium
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
YesY  (what is YesYN ?)
Infobox references

sec-Butyllithium

tert-Butyllithium is a chemical compound with the formula (CH3)3CLi. As an organolithium compound, it has applications in organic synthesis since it is a strong base, capable of deprotonating many carbon acids, including benzene. tert-Butyllithium is available commercially as hydrocarbon solutions; it is not usually prepared in the laboratory. Its synthesis was first reported by R. B. Woodward in 1941.

Like other organolithium compounds, tert-butyllithium is a cluster. Whereas n-butyllithium exists both as a hexamer and a tetramer, tert-Butyllithium exists as tetramer with a cubane structure. Bonding in organolithium clusters involves sigma delocalization and significant Li—Li bonding.

The lithium–carbon bond in tert-butyllithium is highly polarized, having about 40 percent ionic character. The molecule reacts like a carbanion, as is represented by these two resonance structures. (Given the polarity calculations on the C–Li bond, the "real" structure of a single molecule of t-butyllithium is likely a near-average of the two resonance contributors shown, in which the central carbon atom has a ~50% partial negative charge while the lithium atom has a ~50% partial positive charge.)

Similar to n-butyllithium, tert-butyllithium can be used for the exchange of lithium with halogens and for the deprotonation of amines and activated C—H compounds.

This compound and other alkyllithium compounds are known to react with ether solvents; the half-life of tert-butyllithium is 60 minutes at 0 °C in diethyl ether, 40 minutes at −20 °C in tetrahydrofuran (THF), and about 11 minutes at −70 °C in dimethoxyethane. In this example, the reaction of tert-butyllithium with (THF) is shown:


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