Decalin

Chemical compound From Wikipedia, the free encyclopedia

Decalin (decahydronaphthalene, also known as bicyclo[4.4.0]decane and sometimes decaline), a bicyclic organic compound, is an industrial solvent. A colorless liquid with an aromatic odor, it is used as a solvent for many resins or fuel additives.[6]

Quick facts Names, Identifiers ...
Decalin
Decalin
Decalin
Names
Preferred IUPAC name
Decahydronaphthalene[1]
Other names
Bicyclo[4.4.0]decane[1]
Identifiers
3D model (JSmol)
878165
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard 100.001.861 Edit this at Wikidata
EC Number
  • 202-046-9, 207-770-9, 207-771-4
185147
RTECS number
  • QJ3150000
UNII
UN number 1147
  • InChI=1S/C10H18/c1-2-6-10-8-4-3-7-9(10)5-1/h9-10H,1-8H2 checkY
    Key: NNBZCPXTIHJBJL-UHFFFAOYSA-N checkY
  • InChI=1/C10H18/c1-2-6-10-8-4-3-7-9(10)5-1/h9-10H,1-8H2
    Key: NNBZCPXTIHJBJL-UHFFFAOYAH
  • C1CCC2CCCCC2C1
  • cis: C1CC[C@H]2CCCC[C@H]2C1
  • trans: C1CC[C@H]2CCCC[C@@H]2C1
Properties[2]
C10H18
Molar mass 138.254 g·mol−1
Appearance colorless liquid
Odor slight, resembling menthol
Density
  • cis: 0.8965 g/cm3
  • trans: 0.8659 g/cm3
Melting point
  • cis: −42.9 °C (−45.2 °F; 230.2 K)
  • trans: −30.4 °C (−22.7 °F; 242.8 K)
Boiling point
  • cis: 195.8 °C (384.4 °F; 468.9 K)
  • trans: 187.3 °C (369.1 °F; 460.4 K)
Insoluble
Solubility in Ethanol
  • cis: Miscible
  • trans: Very soluble
Solubility in Diethyl ether Very soluble
Solubility in Acetone Very soluble
Solubility in Chloroform cis: Very soluble
Solubility in Benzene trans: Miscible
Solubility in Methanol trans: Soluble
log P 4.79[3]
Vapor pressure
  • 1.3 mbar (1.3 hPa) (22 °C (72 °F; 295 K))[3]
  • 42 mmHg (5.6 kPa) (92 °C (198 °F; 365 K))
  • 741 mmHg (98.8 kPa) (188 °C (370 °F; 461 K))[4]
  • cis: −107.0×10−6 cm3/mol
  • trans: −107.7×10−6 cm3/mol[citation needed]
  • cis: 1.4810
  • trans: 1.4695
Viscosity 3 mPa·s (20 °C (68 °F; 293 K))[3]
Structure[5]
  • cis: C2
  • trans: C2h
Hazards
GHS labelling:[4]
GHS02: FlammableGHS05: CorrosiveGHS06: ToxicGHS08: Health hazardGHS09: Environmental hazard
Danger
H226, H304, H314, H331, H410
P210, P233, P240, P241, P242, P243, P261, P264, P271, P273, P280, P301+P310, P301+P330+P331, P303+P361+P353, P304+P340+P310, P305+P351+P338+P310, P363, P370+P378, P391, P403+P233, P403+P235, P405, P501
NFPA 704 (fire diamond)
[3]
NFPA 704 four-colored diamondHealth 3: Short exposure could cause serious temporary or residual injury. E.g. chlorine gasFlammability 2: Must be moderately heated or exposed to relatively high ambient temperature before ignition can occur. Flash point between 38 and 93 °C (100 and 200 °F). E.g. diesel fuelInstability 1: Normally stable, but can become unstable at elevated temperatures and pressures. E.g. calciumSpecial hazards (white): no code
3
2
1
Flash point 57 °C (135 °F; 330 K)[4]
250 °C (482 °F; 523 K)[4]
Explosive limits 0.7%–4.9% (100 °F (38 °C; 311 K))[4]
Lethal dose or concentration (LD, LC):
  • 4170 mg/kg (oral, rat)
  • 5200 mg/kg (dermal, rabbit)[4]
4.08 mg/L (inhalation, rat)[4]
Related compounds
Related compounds
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Isomers

Decalin occurs in cis and trans forms. The trans form is energetically more stable because of fewer steric effects. 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.[citation needed]

  • 1: trans (left) and cis (right) isomers
    1: trans (left) and cis (right) isomers
  • 2: ball-and-stick model of cis-decalin
    2:
    ball-and-stick model of cis-decalin
  • 3: trans-decalin
    3:
    trans-decalin
  • 4: cis-decalin ring-flip
    4:
    cis-decalin ring-flip

Synthesis

Decalin is the saturated analog of naphthalene and can be prepared from it by hydrogenation in the presence of a catalyst. This interconversion has been considered in the context of hydrogen storage.[7]

Occurrence

Decalin itself is rare in nature but several decalin derivatives are known. They arise via terpene-derived precursors or polyketides.[8]

Reactions

Oxygenation of decalin gives the tertiary hydroperoxide, which rearranges via hydroxycyclodecanone to cyclodecenone, a precursor to sebacic acid.[9]

Safety

Decalin easily forms explosive hydroperoxides upon storage in the presence of air.[10][11]

See also

References

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