{{chembox | Watchedfields = changed | verifiedrevid = 455343751 | Name = Decalin | ImageFile = Decalin.svg | ImageSize = 200px | ImageName = Decalin | PIN = Decahydronaphthalene<ref name=iupac2013>{{cite book | title=Nomenclature of Organic Chemistry : IUPAC Recommendations and Preferred Names 2013 (Blue Book) | publisher=Royal Society of Chemistry |date=2014 |location=Cambridge |pages=33, 394, 601 |isbn=978-0-85404-182-4}}</ref> | OtherNames = Bicyclo[4.4.0]decane<ref name=iupac2013 /> |Section1={{Chembox Identifiers | indexlist_caption = | index_label = | index1_label = ''cis'' | index2_label = ''trans'' | index3_label = | index_comment = | index1_comment = | index2_comment = | index3_comment =
| ChEBI_Ref = {{ebicite|correct|EBI}} | ChEBI = 38853 | ChEBI1 = 38860 | ChEBI2 = 38863 | ChEMBL = 1491920 | SMILES = C1CCC2CCCCC2C1 | SMILES1 = C1CC[C@H]2CCCC[C@H]2C1 | SMILES2 = C1CC[C@H]2CCCC[C@@H]2C1 | ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}} | ChemSpiderID = 6777 | PubChem = 7044 | EC_number = 202-046-9, 207-770-9, 207-771-4 | RTECS = QJ3150000 | UNNumber = 1147 | UNII = 88451Q4XYF | Gmelin = 185147 | Beilstein = 878165 | InChI = 1/C10H18/c1-2-6-10-8-4-3-7-9(10)5-1/h9-10H,1-8H2 | InChIKey = NNBZCPXTIHJBJL-UHFFFAOYAH | StdInChI_Ref = {{stdinchicite|correct|chemspider}} | StdInChI = 1S/C10H18/c1-2-6-10-8-4-3-7-9(10)5-1/h9-10H,1-8H2 | StdInChIKey_Ref = {{stdinchicite|correct|chemspider}} | StdInChIKey = NNBZCPXTIHJBJL-UHFFFAOYSA-N | CASNo = 91-17-8 | CASNo_Ref = {{cascite|correct|CAS}} }} |Section2={{Chembox Properties | Properties_ref = <ref name="CRC85">{{cite book |editor1-last=Lide |editor1-first=David R. |title=CRC Handbook of Chemistry and Physics |date=2004 |publisher=CRC Press |location=Boca Raton, FL |isbn=978-0-8493-0485-9 |page=3—148 |edition=85th |url=https://archive.org/details/B-001-003-529/page/n271/mode/1up}}</ref> | C=10 | H=18 | Appearance = colorless liquid | Odor = slight, resembling menthol | Density = {{ubl |''cis'': {{val|0.8965|u=g/cm3}} |''trans'': {{val|0.8659|u=g/cm3}} }} | MeltingPt = {{ubl |''cis'': {{cvt|−42.9|C|F K}} |''trans'': {{cvt|−30.4|C|F K}} }} | BoilingPt = {{ubl |''cis'': {{cvt|195.8|C|F K}} |''trans'': {{cvt|187.3|C|F K}} }} | Solubility = Insoluble | Solvent1 = Ethanol | Solubility1 = {{ubl |''cis'': Miscible |''trans'': Very soluble }} | Solvent2 = Diethyl ether | Solubility2 = Very soluble | Solvent3 = Acetone | Solubility3 = Very soluble | Solvent4 = Chloroform | Solubility4 = ''cis'': Very soluble | Solvent5 = Benzene | Solubility5 = ''trans'': Miscible | Solvent6 = Methanol | Solubility6 = ''trans'': Soluble | VaporPressure = {{ubl |{{cvt|1.3|mbar}} ({{cvt|22|C|F K}})<ref name="FisherSDS"/> |{{cvt|42|mmHg}} ({{cvt|92|C|F K}}) |{{cvt|741|mmHg}} ({{cvt|188|C|F K}})<ref name="Sigma"/> }} | LogP = 4.79<ref name="FisherSDS"/> | MagSus = {{ubl |''cis'': {{val|-107.0|e=-6|u=cm3/mol}} |''trans'': {{val|-107.7|e=-6|u=cm3/mol}}{{cn|date=January 2026}} }} | RefractIndex = {{ubl |''cis'': 1.4810 |''trans'': 1.4695 }} | Viscosity = {{val|3|u=mPa·s}} ({{cvt|20|C|F K}})<ref name="FisherSDS"/> }} | Section3 = {{Chembox Structure | Structure_ref = <ref name=Eliel1994>{{cite book |last1=Eliel |first1=Ernest Ludwig |last2=Wilen |first2=Samuel H. |last3=Mander |first3=Lewis N. |title=Stereochemistry of Organic Compounds |publisher=Wiley |publication-place=New York |date=1994 |isbn=978-0-471-01670-0 |page=777 |url=https://archive.org/details/stereochemistryo0000elie_b4d8/page/777/mode/2up?q=decalin}}</ref> | PointGroup = {{ubl |''cis'': C<sub>2</sub> |''trans'': C<sub>2h</sub> }} }} |Section7={{Chembox Hazards | GHS_ref = <ref name="Sigma">{{Sigma-Aldrich|sial|id=294772|name=Decahydronapthalene (cis, trans)}}</ref> | GHSPictograms = {{GHS02}}{{GHS05}}{{GHS06}}{{GHS08}}{{GHS09}} | GHSSignalWord = Danger | HPhrases = {{H-phrases|226|304|314|331|410}} | PPhrases = {{P-phrases|210|233|240|241|242|243|261|264|271|273|280|301+310|301+330+331|303+361+353|304+340+310|305+351+338+310|363|370+378|391|403+233|403+235|405|501}} | NFPA-H = 3 | NFPA-F = 2 | NFPA-R = 1 | NFPA-S = - | NFPA_ref = <ref name="FisherSDS">{{cite web |url=https://documents.thermofisher.com/DirectWebViewer/private/document.aspx?prd=ALFAAA13883~~PDF~~MTR~~AGHS~~EN~~2025-12-22%2010:09:45~~Decahydronaphthalene~~ |title=SDS - Decahydronapthalene |website=thermofisher.com |publisher=ThermoFisher Scientific |access-date=26 January 2026 |page=4 |format=pdf |date=21 December 2025}}</ref> | FlashPtC = 57 | FlashPt_ref = <ref name="Sigma"/> | AutoignitionPtC = 250 | AutoignitionPt_ref = <ref name="Sigma"/> | ExploLimits = {{val|0.7|-|4.9|u=%}} ({{cvt|100|F|C K}})<ref name="Sigma"/> | LD50 = {{ubl |{{val|4170|u=mg/kg}} (oral, rat) |{{val|5200|u=mg/kg}} (dermal, rabbit)<ref name="Sigma"/> }} | LC50 = {{val|4.08|u=mg/L}} (inhalation, rat)<ref name="Sigma"/> }} |Section8={{Chembox Related | OtherCompounds = {{ubl |Naphthalene |Tetralin }} }} }} '''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.<ref>{{cite web |url=http://www.decalinchemicals.com/fueladditive.html |title=Fuel Additive Product |url-status=dead |archive-url=https://web.archive.org/web/20090312073209/http://decalinchemicals.com/fueladditive.html |archive-date=2009-03-12 }}</ref>
== 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.{{cn|date=January 2026}}
<gallery mode="packed"> Image:Cis-trans isomerism of decahydronaphthalene.svg|{{center|'''1:''' ''trans'' (left) and ''cis'' (right) isomers}} Image:cis-decalin double chair.png|'''2:''' {{center|ball-and-stick model of ''cis''-decalin}} Image:trans-decalin double chair.png|'''3:''' {{center|''trans''-decalin}} File:Cisdecalin conformations.png|'''4:''' {{center|''cis''-decalin ring-flip}} </gallery>
==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.<ref>{{cite journal |doi=10.1016/j.rser.2017.04.006|title=Hydrogen donor solvents in liquefaction of biomass: A review |year=2018 |last1=Isa |first1=Khairuddin Md |last2=Abdullah |first2=Tuan Amran Tuan |last3=Ali |first3=Umi Fazara Md |journal=Renewable and Sustainable Energy Reviews |volume=81 |pages=1259–1268 |bibcode=2018RSERv..81.1259I }}</ref>
==Occurrence== Decalin itself is rare in nature but several decalin derivatives are known. They arise via terpene-derived precursors or polyketides.<ref>{{cite journal |doi=10.1039/C4NP00031E|title=Natural products containing 'decalin' motif in microorganisms |year=2014 |last1=Li |first1=Gang |last2=Kusari |first2=Souvik |last3=Spiteller |first3=Michael |journal=Nat. Prod. Rep. |volume=31 |issue=9 |pages=1175–1201 |pmid=24984916 |doi-access=free }}</ref>
==Reactions== Oxygenation of decalin gives the tertiary hydroperoxide, which rearranges via hydroxycyclodecanone to {{chem name|cyclodecenone}}, a precursor to sebacic acid.<ref name=Ull>{{Ullmann|doi=10.1002/14356007.a13_227|title=Hydrocarbons|year=2000|last1=Griesbaum|first1=Karl|last2=Behr|first2=Arno|last3=Biedenkapp|first3=Dieter|last4=Voges|first4=Heinz-Werner|last5=Garbe|first5=Dorothea|last6=Paetz|first6=Christian|last7=Collin|first7=Gerd|last8=Mayer|first8=Dieter|last9=Höke|first9=Hartmut}}</ref>
==Safety== Decalin easily forms explosive hydroperoxides upon storage in the presence of air.<ref>{{cite thesis |last=Agosta |first=Alessandro |url=http://idea.library.drexel.edu/bitstream/1860/16/11/agosta_thesis.pdf |title=Development of a Chemical Surrogate for JP-8 Aviation Fuel Using a Pressurized Flow Reactor |degree=MS |date=May 2002 |publisher=Drexel University |location=Philadelphia, PA |url-status=dead |archive-url=https://web.archive.org/web/20100619083556/http://idea.library.drexel.edu/bitstream/1860/16/11/agosta_thesis.pdf |archive-date=2010-06-19 }}</ref><ref>{{ICSC|1548}}</ref>
== See also == * Dialin * Geosmin * Perfluorodecalin
==References== {{Reflist}}
{{Authority control}} Category:Hydrocarbon solvents Category:Decalins Category:Bicycloalkanes