Decalin

From Sciencemadness Wiki
Jump to: navigation, search
Decalin
Names
IUPAC name
Decahydronaphthalene
Other names
Bicyclo[4.4.0]decane
Decaline
Properties
C10H18
Molar mass 138.25 g/mol
Appearance Colorless liquid
Odor Aromatic
Density 0.896 g/cm3
Melting point trans: −30.4 °C (−22.7 °F; 242.7 K)
cis: −42.9 °C (−45.2 °F; 230.3 K)
Boiling point trans: 187 °C (369 °F; 460 K)
cis: 196 °C (384 °F; 469 K)
0.089 mg/100 ml (25 °C)
Solubility Miscible with acetone, benzene, chloroform, diethyl ether, DMSO, ethanol, ethyl acetate, heptane, hexane, isopropanol, methyl ethyl ketone, methanol, propanol, pyridine, toluene, xylene
Slightly soluble in glacial acetic acid
Vapor pressure 2.3 mmHg at 25 °C
Hazards
Safety data sheet Sigma-Aldrich (cis)
Sigma-Aldrich (trans)
Sigma-Aldrich (mixture)
Flash point 57 °C (135 °F; 330 K)
Lethal dose or concentration (LD, LC):
4.170 mg/kg (rat, oral)
Related compounds
Related compounds
Naphthalene
Tetralin
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Decalin, also known as decahydronaphthalene is a bicyclic organic compound, used as laboratory and industrial solvent. It has the chemical formula C10H18.

Decalin occurs in cis and trans forms. The trans form is energetically more stable because of fewer steric interactions. cis-Decalin is a chiral molecule without a chiral center; it has a two-fold rotational symmetry axis, but no reflective symmetry. However, the chirality is canceled through a chair-flipping process that turns the molecule into its mirror image.

Properties

Chemical

Oxygenation of decalin give the tertiary hydroperoxide, which rearranges to cyclodecenone, a precursor to sebacic acid.

Physical

Decalin is a colorless liquid, immiscible with water, but miscible with many organic solvents. It has an aromatic odor described as being close to menthol, but different from tetralin or naphthalene.

Availability

Decalin is sold by chemical suppliers.

Preparation

Complete hydrogenation of naphthalene or tetralin in the presence of platinum or nickel catalyst yields decalin.

Projects

  • Solvent for heavy aromatic compounds
  • Moieties in transition-metal complex catalysts

Handling

Safety

Decalin is irritant and should be handled with care. With a flash point of 57 °C, it is not very flammable and unless heated prior, it doesn't pose a serious fire hazard.

Storage

In closed air-tight bottles. Since it is known to form peroxides in contact upon prolonged contact with air, it's best to test it for peroxides every few months. These peroxides are dangerous upon concentration, since they can explode. Sodium metal can be added to chemically destroy the peroxides.

Disposal

Should be mixed with a more flammable solvent and burned.

References

Relevant Sciencemadness threads