Cyclopentane

Cyclopentane
IUPAC name Cyclopentane
Other names pentamethylene
Identifiers
CAS number	287-92-3 Y
PubChem	9253
ChemSpider	8896 Y
ChEBI	CHEBI:23492 Y
RTECS number	GY2390000
Jmol-3D images	Image 1
SMILES C1CCCC1
InChI InChI=1S/C5H10/c1-2-4-5-3-1/h1-5H2 Y Key: RGSFGYAAUTVSQA-UHFFFAOYSA-N Y InChI=1/C5H10/c1-2-4-5-3-1/h1-5H2 Key: RGSFGYAAUTVSQA-UHFFFAOYAL
Properties
Molecular formula	C5H10
Molar mass	70.1 g/mol
Appearance	clear, colorless liquid
Density	0.751 g/cm3
Melting point	−94 °C
Boiling point	49 °C, 322 K, 120 °F
Acidity (pKa)	~45
Related compounds
Related compounds	cyclopropane, cyclobutane, cyclohexane
Y (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Cyclopentane is a highly flammable alicyclic hydrocarbon with chemical formula C₅H₁₀ and CAS number 287-92-3, consisting of a ring of five carbon atoms each bonded with two hydrogen atoms above and below the plane. It occurs as a colorless liquid with a petrol-like odor. Its melting point is −94 °C and its boiling point is 49 °C. Cyclopentane is in the class of cycloalkanes, being alkanes that have one or more rings of carbon atoms.

The typical structure of cyclopentane is the "envelope" conformation.

Industrial usage

Cyclopentane is used in the manufacture of synthetic resins and rubber adhesives and also as a blowing agent in the manufacture of polyurethane insulating foam, as found in many domestic appliances such as refrigerators and freezers, replacing environmentally damaging alternatives such as CFC-11 and HCFC-141b

More advanced technologies, such as computer hard drives and outerspace equipment employ multiply alkylated cyclopentane (MAC) lubricants because of their extremely low volatility.

The United States produces more than half a million kilograms of this chemical per year.

Formulation of cycloalkanes

Cycloalkanes can be formulated via a process known as catalytic reforming.

For example, 2-methylbutane can be reformed into cyclopentane, by use of a platinum catalyst. This is particularly well known in automobiles, as branched alkanes will burn much more readily.