Decalin

Decalin
Names
	Preferred IUPAC name Decahydronaphthalene
	Other names Bicyclo[4.4.0]decane; Decalin
Identifiers
CAS Number	91-17-8 ;
3D model (JSmol)	Interactive image; cis: Interactive image; trans: Interactive image;
Beilstein Reference	878165
ChEBI	CHEBI:38853 ; cis: CHEBI:38860; trans: CHEBI:38863;
ChEMBL	ChEMBL1491920;
ChemSpider	6777 ;
ECHA InfoCard	100.001.861
EC Number	202-046-9, 207-770-9, 207-771-4;
Gmelin Reference	185147
PubChem CID	7044;
RTECS number	QJ3150000;
UNII	88451Q4XYF;
UN number	1147
CompTox Dashboard (EPA)	DTXSID1024912 ;
	InChI InChI=1S/C10H18/c1-2-6-10-8-4-3-7-9(10)5-1/h9-10H,1-8H2 Key: NNBZCPXTIHJBJL-UHFFFAOYSA-N ; InChI=1/C10H18/c1-2-6-10-8-4-3-7-9(10)5-1/h9-10H,1-8H2 Key: NNBZCPXTIHJBJL-UHFFFAOYAH;
	SMILES C1CCC2CCCCC2C1; cis: C1CC[C@H]2CCCC[C@H]2C1; trans: C1CC[C@H]2CCCC[C@@H]2C1;
Properties
Chemical formula	C10H18
Molar mass	138.25 g/mol
Appearance	colorless liquid
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); cis: 196 °C (384 °F)
Solubility in water	Insoluble
Magnetic susceptibility (χ)	−107.7·10−6 cm3/mol (trans); −107.0·10−6 cm3/mol (cis);
Refractive index (nD)	1.481
Hazards
	GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H226, H302, H305, H314, H331, H332, H410, H411
Precautionary statements	P210, P233, P240, P241, P242, P243, P260, P261, P264, P271, P273, P280, P301+P310, P301+P330+P331, P303+P361+P353, P304+P312, P304+P340, P305+P351+P338, P310, P311, P312, P321, P331, P363, P370+P378, P391, P403+P233, P403+P235, P405, P501
Flash point	57 °C (135 °F; 330 K)
Autoignition; temperature	250 °C (482 °F; 523 K)
Safety data sheet (SDS)	Decalin MSDS
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). verify (what is ?) Infobox references

Decalin (decahydronaphthalene, also known as bicyclo[4.4.0]decane and sometimes decaline),^[3] 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.^[4]

Isomers

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.

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

trans-Decalin

The only possible way to join the two six-membered rings in the trans position means the second ring needs to start from two equatorial bonds (blue) of the first ring. A six-membered ring does not offer sufficient space to start out on an axial position (upwards), and reach the axial position of the neighboring carbon atom, which then will be on the downwards side of the molecule (see the model of cyclohexane in figure 5). The structure is conformationally frozen. It does not have the ability to undergo a chair flip as in the cis isomer. In biology this fixation is widely used in the steroid skeleton to construct molecules (such as figure 6) that play a key role in the signalling between distantly separated cells.

Reactions

Oxygenation of decalin gives the tertiary hydroperoxide, which rearranges to cyclodecenone, a precursor to sebacic acid.^[5]

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.^[6]

Derivation

Treatment of naphthalene in a fused state with hydrogen in the presence of a copper or nickel catalyst. ^[7]

Occurrence

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

Safety

Decalin easily forms explosive^[9] hydroperoxides upon storage in the presence of air.^[10]^[11]

References

^ ^a ^b Nomenclature of Organic Chemistry : IUPAC Recommendations and Preferred Names 2013 (Blue Book). Cambridge: The Royal Society of Chemistry. 2014. pp. 33, 394, 601. doi:10.1039/9781849733069-FP001. ISBN 978-0-85404-182-4.
^ Haynes, William M. (2010). Handbook of Chemistry and Physics (91 ed.). Boca Raton, Florida, USA: CRC Press. p. 3-134. ISBN 978-1-43982077-3.
^ "Dictionary.com".
^ "Fuel Additive Product". Archived from the original on 2009-03-12.
^ Griesbaum, Karl; Behr, Arno; Biedenkapp, Dieter; Voges, Heinz-Werner; Garbe, Dorothea; Paetz, Christian; Collin, Gerd; Mayer, Dieter; Höke, Hartmut (2000). "Hydrocarbons". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a13_227. ISBN 3527306730.
^ Isa, Khairuddin Md; Abdullah, Tuan Amran Tuan; Ali, Umi Fazara Md (2018). "Hydrogen donor solvents in liquefaction of biomass: A review". Renewable and Sustainable Energy Reviews. 81: 1259–1268. Bibcode:2018RSERv..81.1259I. doi:10.1016/j.rser.2017.04.006.
^ [Hawley's Condensed Chemical Dictionary]
^ Li, Gang; Kusari, Souvik; Spiteller, Michael (2014). "Natural products containing 'decalin' motif in microorganisms". Nat. Prod. Rep. 31 (9): 1175–1201. doi:10.1039/C4NP00031E. PMID 24984916.
^ "PDF – Surrogate JP-8 Aviation Fuel Study – Alessandro Agosta Thesis Drexel University" (PDF). Archived from the original (PDF) on 2010-06-19.
^ "Inchem.org Data".
^ "MSDS Sheet – JT Baker".

[iupac2013-1] Nomenclature of Organic Chemistry : IUPAC Recommendations and Preferred Names 2013 (Blue Book). Cambridge: The Royal Society of Chemistry. 2014. pp. 33, 394, 601. doi:10.1039/9781849733069-FP001. ISBN 978-0-85404-182-4.

[2] Haynes, William M. (2010). Handbook of Chemistry and Physics (91 ed.). Boca Raton, Florida, USA: CRC Press. p. 3-134. ISBN 978-1-43982077-3.

[3] "Dictionary.com".

[4] "Fuel Additive Product". Archived from the original on 2009-03-12.

[Ull-5] Griesbaum, Karl; Behr, Arno; Biedenkapp, Dieter; Voges, Heinz-Werner; Garbe, Dorothea; Paetz, Christian; Collin, Gerd; Mayer, Dieter; Höke, Hartmut (2000). "Hydrocarbons". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a13_227. ISBN 3527306730.

[6] Isa, Khairuddin Md; Abdullah, Tuan Amran Tuan; Ali, Umi Fazara Md (2018). "Hydrogen donor solvents in liquefaction of biomass: A review". Renewable and Sustainable Energy Reviews. 81: 1259–1268. Bibcode:2018RSERv..81.1259I. doi:10.1016/j.rser.2017.04.006.

[7] [Hawley's Condensed Chemical Dictionary]

[8] Li, Gang; Kusari, Souvik; Spiteller, Michael (2014). "Natural products containing 'decalin' motif in microorganisms". Nat. Prod. Rep. 31 (9): 1175–1201. doi:10.1039/C4NP00031E. PMID 24984916.

[9] "PDF – Surrogate JP-8 Aviation Fuel Study – Alessandro Agosta Thesis Drexel University" (PDF). Archived from the original (PDF) on 2010-06-19.

[10] "Inchem.org Data".

[11] "MSDS Sheet – JT Baker".

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