Lithium cyclopentadienide is an
organolithium compound
In organometallic chemistry, organolithium reagents are chemical compounds that contain carbon–lithium (C–Li) bonds. These reagents are important in organic synthesis, and are frequently used to transfer the organic group or the lithium atom ...
with the
formula
In science, a formula is a concise way of expressing information symbolically, as in a mathematical formula or a ''chemical formula''. The informal use of the term ''formula'' in science refers to the general construct of a relationship betwe ...
C
5H
5Li. The compound is often abbreviated as LiCp, where Cp
− is the cyclopentadienide anion. Lithium cyclopentadienide is a colorless solid, although samples often are pink owing to traces of oxidized impurities.
Preparation, structure and reactions
Lithium cyclopentadienide is commercially available as a solution in
tetrahydrofuran
Tetrahydrofuran (THF), or oxolane, is an organic compound with the formula (CH2)4O. The compound is classified as heterocyclic compound, specifically a cyclic ether. It is a colorless, water- miscible organic liquid with low viscosity. It is ...
. It is prepared by treating
cyclopentadiene
Cyclopentadiene is an organic compound with the chemical formula, formula C5H6. It is often abbreviated CpH because the cyclopentadienyl anion is abbreviated Cp−.
This colorless liquid has a strong and unpleasant odor. At room temperature, ...
with
butyllithium Butyllithium may refer to one of 5 isomeric organolithium reagents of which 3 are commonly used in chemical synthesis:
* ''n''-Butyllithium, abbreviated BuLi or nBuLi
* ''sec''-Butyllithium, abbreviated ''sec''-BuLi or sBuLi, has 2 stereoisomers, ...
:
:C
5H
6 + LiC
4H
9 → LiC
5H
5 + C
4H
10
Because lithium cyclopentadienide is usually handled as a solution, the solvent-free solid is rarely encountered. According to
X-ray crystallography
X-ray crystallography is the experimental science of determining the atomic and molecular structure of a crystal, in which the crystalline structure causes a beam of incident X-rays to Diffraction, diffract in specific directions. By measuring th ...
, LiCp is a "polydecker"
sandwich complex
In organometallic chemistry, a sandwich compound is a chemical compound featuring a metal bound by hapticity, haptic, covalent bonds to two arene compound, arene (ring) ligands. The arenes have the formula , substituted derivatives (for example ...
, consisting of an infinite chain of alternating Li
+ centers sandwiched between
''μ''-
''η''5:''η''
5-C
5H
5 ligands.
In the presence of amines or ethers, LiCp gives adducts, e.g. (''η''
5-Cp)Li(TMEDA).
[ LiCp is a common reagent for the preparation of ]cyclopentadienyl complex
A cyclopentadienyl complex is a coordination complex of a metal and cyclopentadienyl groups (, abbreviated as Cp−). Cyclopentadienyl ligands almost invariably bind to metals as a pentahapto (''η''5-) bonding mode. The metal–cyclopentadien ...
es.
See also
*Sodium cyclopentadienide
Sodium cyclopentadienide is an organosodium compound with the formula C5H5Na. The compound is often abbreviated as NaCp, where Cp− is the cyclopentadienide anion. Sodium cyclopentadienide is a colorless solid, although samples often are pin ...
References
{{Cyclopentadiene complexes
Cyclopentadienyl complexes
Non-benzenoid aromatic carbocycles
Organolithium compounds