Trimethylsilyl cyclopentadiene is an
organosilicon compound
Organosilicon chemistry is the study of organometallic compounds containing carbon–silicon bonds, to which they are called organosilicon compounds. Most organosilicon compounds are similar to the ordinary organic compounds, being colourless, f ...
with the chemical formula C
5H
5Si(CH
3)
3. It exists as a colorless liquid. It is used in the synthesis of some metal
cyclopentadienyl Cyclopentadienyl can refer to
* Cyclopentadienyl anion, or cyclopentadienide,
** Cyclopentadienyl ligand
* Cyclopentadienyl radical, •
* Cyclopentadienyl cation,
See also
* Pentadienyl
{{Chemistry index ...
complexes and has attracted interest for its
fluxional structure.
Trimethylsilyl cyclopentadiene is an example of a
molecule
A molecule is a group of two or more atoms that are held together by Force, attractive forces known as chemical bonds; depending on context, the term may or may not include ions that satisfy this criterion. In quantum physics, organic chemi ...
that undergoes rapid
sigmatropic rearrangement
In organic chemistry, a sigmatropic reaction () is a pericyclic reaction wherein the net result is one sigma bond (σ-bond) is changed to another σ-bond in an intramolecular reaction. In this type of rearrangement reaction, a substituent moves f ...
. Observations of trimethylsilyl cyclopentadiene using gas phase
NMR spectroscopy
Nuclear magnetic resonance spectroscopy, most commonly known as NMR spectroscopy or magnetic resonance spectroscopy (MRS), is a spectroscopic technique based on re-orientation of atomic nuclei with non-zero nuclear spins in an external magnetic f ...
show that the protons on the ring are chemically equivalent, indicated by a single peak. This phenomenon, an example of
fluxionality, is explained by the migration of the silyl group from carbon-to-carbon, thereby giving the appearance of equivalent CH signals.
Properties:
refractive index ''n''20/D 1.471(lit.)
bp 138-140 °C(lit.)
density 0.833 g/mL at 25 °C(lit.)
storage temp. −20 °C
Synthesis
Trimethylsilyl cyclopentadiene is prepared by the reaction
trimethylsilyl chloride
Trimethylsilyl chloride, also known as chlorotrimethylsilane is an organosilicon compound ( silyl halide), with the formula , often abbreviated or TMSCl. It is a colourless volatile liquid that is stable in the absence of water. It is widely u ...
(Me
3SiCl) with
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 ...
(NaC
5H
5):
:(CH
3)
3SiCl + NaC
5H
5 → C
5H
5Si(CH
3)
3 + NaCl
References
{{Reflist
Cyclopentadienes
Trimethylsilyl compounds