Cubane

{{Short description|Organic compound (C8H8) with a cube carbon structure}} {{chembox | Watchedfields = changed | verifiedrevid = 443545029 | Name = Cubane | ImageFile = Cuban.svg | ImageClass = skin-invert-image | ImageFileL1 = cubane-cpk.png | ImageClassL1 = bg-transparent | ImageNameL1 = CPK model of Cubane. | ImageFileR1 = Cubane molecule ball.png | ImageClassR1 = bg-transparent | ImageName = Structural formula of cubane | ImageNameR1 = Ball-and-stick model of cubane | PIN = Cubane<ref name=iupac2013>{{cite book | title = Nomenclature of Organic Chemistry : IUPAC Recommendations and Preferred Names 2013 (Blue Book) | publisher = The Royal Society of Chemistry | date = 2014 | location = Cambridge | page = 169 | doi = 10.1039/9781849733069-FP001 | isbn = 978-0-85404-182-4 | quote = The retained names adamantane and cubane are used in general nomenclature and as preferred IUPAC names.}}</ref> | SystematicName = Pentacyclo[4.2.0.02,5.03,8.04,7]octane | OtherNames = | Section1 = {{Chembox Identifiers | ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}} | ChemSpiderID = 119867 | PubChem = 136090 | InChIKey = TXWRERCHRDBNLG-UHFFFAOYAL | StdInChI_Ref = {{stdinchicite|correct|chemspider}} | StdInChI = 1S/C8H8/c1-2-5-3(1)7-4(1)6(2)8(5)7/h1-8H | StdInChIKey_Ref = {{stdinchicite|correct|chemspider}} | StdInChIKey = TXWRERCHRDBNLG-UHFFFAOYSA-N | CASNo_Ref = {{cascite|correct|??}} | CASNo = 277-10-1 | UNII_Ref = {{fdacite|correct|FDA}} | UNII = Z5HM0Q7DK1 | ChEBI_Ref = {{ebicite|correct|EBI}} | ChEBI = 33014 | SMILES = C12C3C4C1C5C2C3C45 | InChI = 1/C8H8/c1-2-5-3(1)7-4(1)6(2)8(5)7/h1-8H }} | Section2 = {{Chembox Properties | Formula = {{chem2|C8H8}} | MolarMass = 104.15 g/mol | Density = 1.29 g/cm3 | Appearance = Transparent<ref name=ch>{{cite web | url=https://www.ch.ic.ac.uk/local/projects/b_muir/Cubane/Cubanepro/Start.html | title=Start }}</ref> crystalline solid | MeltingPtC = 133.5 | MeltingPt_ref = <ref name = Biegasiewicz /> | BoilingPtC = 161.6 | BoilingPt_ref = <ref name= Biegasiewicz /> }} | Section8 = {{Chembox Related | OtherFunction = Cuneane Dodecahedrane Tetrahedrane Prismane Prismane C8 | OtherFunction_label = hydrocarbons | OtherCompounds = Octafluorocubane Octanitrocubane Octaazacubane Mirex }} }} '''Cubane''' is a synthetic hydrocarbon compound with the formula {{chem2|C8H8}}. It consists of eight carbon atoms arranged at the corners of a cube, with one hydrogen atom attached to each carbon atom. A solid crystalline substance, cubane is one of the Platonic hydrocarbons and a member of the prismanes. It was first synthesized in 1964 by Philip Eaton and Thomas Cole.<ref name="eaton-1964" /> Before this work, Eaton believed that cubane would be impossible to synthesize due to the "required 90 degree bond angles".<ref>{{cite book |last1=Teachers |first1=University of New South Wales Summer School for Chemistry |title=Approach to Chemistry: Lectures and Workshop Reports of the ... Summer School for Chemistry Teachers |date=1963 |publisher=The University |page=98 |url=https://books.google.com/books?id=cFA0AQAAIAAJ |language=en}} "This compound was described only a few months ago and, curiously enough, it is quite easy to make, although only a year ago I would have predicted that it would be difficult, or even impossible, to synthesize."</ref><ref>{{cite book |last1=Moore |first1=John W. |last2=Stanitski |first2=Conrad L. |last3=Jurs |first3=Peter C. |title=Chemistry: The Molecular Science |date=2002 |publisher=Harcourt College Publishers |isbn=978-0-03-032011-8 |page=372 |url=https://books.google.com/books?id=XjcvAQAAIAAJ |language=en}} "This sharp bond angle creates severe bond strain in cubane, a compound thought previously impossible to synthesize because of the required 90° bond angles."</ref> The cubic shape requires the carbon atoms to adopt an unusually sharp 90° bonding angle, which would be highly strained as compared to the 109.45° angle of a tetrahedral carbon. Once formed, cubane is quite kinetically stable, due to a lack of readily available decomposition paths. It is the simplest hydrocarbon with octahedral symmetry.

Having high potential energy and kinetic stability makes cubane and its derivative compounds useful for controlled energy storage. For example, octanitrocubane and heptanitrocubane have been studied as high-performance explosives. These compounds also typically have a very high density for hydrocarbon molecules. The resulting high energy density means a large amount of energy can be stored in a comparably smaller amount of space, an important consideration for applications in fuel storage and energy transport. Furthermore, their geometry and stability make them suitable isosteres for benzene rings.<ref>{{Cite journal |last1=Wiesenfeldt |first1=Mario P. |last2=Rossi-Ashton |first2=James A. |last3=Perry |first3=Ian B. |last4=Diesel |first4=Johannes |last5=Garry |first5=Olivia L. |last6=Bartels |first6=Florian |last7=Coote |first7=Susannah C. |last8=Ma |first8=Xiaoshen |last9=Yeung |first9=Charles S. |last10=Bennett |first10=David J. |last11=MacMillan |first11=David W. C. |date=June 2023 |title=General access to cubanes as benzene bioisosteres |journal=Nature |language=en |volume=618 |issue=7965 |pages=513–518 |doi=10.1038/s41586-023-06021-8 |pmid=37015289 |issn=1476-4687|pmc=10680098 |bibcode=2023Natur.618..513W }}</ref>

==Synthesis== The classic 1964 synthesis starts with the conversion of 2-cyclopentenone to 2-bromocyclopentadienone:<ref name="eaton-1964"/><ref name=eaton1964 />

500px|class=skin-invert

Allylic bromination with ''N''-bromosuccinimide in carbon tetrachloride followed by addition of molecular bromine to the alkene gives a 2,3,4-tribromocyclopentanone. Treating this compound with diethylamine in diethyl ether causes elimination of two equivalents of hydrogen bromide to give the diene product.

thumb| class=skin-invert-image|left|500px|Eaton's 1964 synthesis of cubane{{clear left}}

The construction of the eight-carbon cubane framework begins when 2-bromocyclopentadienone undergoes a spontaneous Diels-Alder dimerization. One ketal of the ''endo'' isomer is subsequently selectively deprotected with aqueous hydrochloric acid to '''3'''.

In the next step, the ''endo'' isomer '''3''' (with both alkene groups in close proximity) forms the cage-like isomer '''4''' in a photochemical [2+2] cycloaddition. The bromoketone group is converted to ring-contracted carboxylic acid '''5''' in a Favorskii rearrangement with potassium hydroxide. Next, the thermal decarboxylation takes place through the acid chloride (with thionyl chloride) and the ''tert''-butyl perester '''6''' (with ''tert''-butyl hydroperoxide and pyridine) to '''7'''; afterward, the acetal is once more removed in '''8'''. A second Favorskii rearrangement gives '''9''', and finally another decarboxylation gives, via '''10''', cubane ('''11''').

A more approachable laboratory synthesis of disubstituted cubane involves bromination of the ethylene ketal of cyclopentanone to give a tribromocyclopentanone derivative. Subsequent steps involve dehydrobromination, Diels-Alder dimerization, etc.<ref>{{Cite journal|doi=10.1071/C97021|title=Dimethyl Cubane-1,4-dicarboxylate: A Practical Laboratory Scale Synthesis|year=1997|last1=Bliese|first1=Marianne|last2=Tsanaktsidis|first2=John|journal=Australian Journal of Chemistry|volume=50|issue=3|page=189}}</ref><ref>{{Cite web|author =Fluorochem, Inc|date=July 1989|title=Cubane Derivatives for Propellant Applications|url=https://apps.dtic.mil/sti/pdfs/ADA210368.pdf|url-status=live|archive-url=https://web.archive.org/web/20210709185435/https://apps.dtic.mil/sti/pdfs/ADA210368.pdf |archive-date=2021-07-09 }}</ref>

Alternative synthesis of a disubstituted cubane|555x555px|class=skin-invert|center The resulting '''cubane-1,4-dicarboxylic acid''' is used to synthesize other substituted cubanes. Cubane itself can be obtained nearly quantitatively by photochemical decarboxylation of the thiohydroxamate ester (the Barton decarboxylation).<ref>{{Cite journal |last=Eaton |first=Philip E. |date=1992 |title=Cubane: Ausgangsverbindungen für die Chemie der neunziger Jahre und des nächsten Jahrhunderts |url=https://onlinelibrary.wiley.com/doi/10.1002/ange.19921041105 |journal=Angewandte Chemie |language=de |volume=104 |issue=11 |pages=1447–1462 |doi=10.1002/ange.19921041105|bibcode=1992AngCh.104.1447E |url-access=subscription }}</ref>

==Reactions and derivatives== [[File:Cubane locants.svg|class=skin-invert-image|right|thumb|80px|{{nowrap|Cubane locants}}]] Cubane is highly strained, but cannot decompose because the resultant cubene molecules are pyramidal alkenes, too high-energy for most elimination pathways. Certain metallic ions catalyze σ-bond rearrangement to cuneane:<ref name=March /><ref name=kindler /> :176x176px|class=skin-invert With a rhodium catalyst, cubane first forms ''syn''-tricyclooctadiene, which can thermally decompose to cyclooctatetraene at 50–60 °C.<ref>{{Cite journal |last1=Cassar |first1=Luigi |last2=Eaton |first2=Philip E. |last3=Halpern |first3=Jack |date=1970 |title=Catalysis of symmetry-restricted reactions by transition metal compounds. Valence isomerization of cubane |url=https://pubs.acs.org/doi/abs/10.1021/ja00714a075 |journal=Journal of the American Chemical Society |language=en |volume=92 |issue=11 |pages=3515–3518 |doi=10.1021/ja00714a075 |bibcode=1970JAChS..92.3515C |issn=0002-7863|url-access=subscription }}</ref> :400x400px|class=skin-invert

The main cubane functionalization challenge is C-H bond activation. Cubenes still inhibit decomposition during radical substitution, but the reaction offers little control against oversubstitution. In polar reactions, cubane reacts somewhat similarly to arenes or other cluster compounds: it metallates easily.<ref name=ReactivitySurvey>{{cite web|website=Cubane|first=B.|last=Muir|publisher=Imperial College London|title=Reactivity|url=https://www.ch.ic.ac.uk/local/projects/b_muir/Cubane/Cubanepro/Reactivity.html|access-date=22 May 2025|url-status=live|archive-url=https://web.archive.org/web/20240119125713/https://www.ch.ic.ac.uk/local/projects/b_muir/Cubane/Cubanepro/Reactivity.html|archive-date=19 Jan 2024}}</ref> Cubane is slightly acidic, deprotonating about 63000 times faster than cyclohexane.<ref>{{cite web|website=Cubane|first=B.|last=Muir|publisher=Imperial College London|title=Properties|at=The nature of the C–H bond|url=https://www.ch.ic.ac.uk/local/projects/b_muir/Cubane/Cubanepro/Properties.html|access-date=22 May 2025|url-status=live|archive-url=https://web.archive.org/web/20240119125716/https://www.ch.ic.ac.uk/local/projects/b_muir/Cubane/Cubanepro/Properties.html|archive-date=19 Jan 2024}}</ref>

Cubane substituents generally display normal reactivity. For example a Curtius rearrangement followed by organic oxidation converts {{chem name|cubane tetra(carbonylchloride)}} to tetranitrocubane.<ref name=ReactivitySurvey/> However, electron-rich substituents such as alcohols can enable decomposition; they stabilize the cubene intermediate as a ketone (or equivalent) tautomer.<ref name=MMisc/>

Oxalyl chloride oxidizes cubane carboxamides to give a norcubane-furanone derivative.<ref>{{cite journal|doi=10.1016/S0040-4039(97)10185-X|publisher=Pergamon (Elsevier)|journal=Tetrahedron Letters|volume=38|issue=47|pages=8137–8140|year=1997|title=Norcubanes from Cubanes: Novel reactions of amidocubanes with oxalyl chloride|first1=A.|last1=Bashir-Hashemi|first2=Nathan|last2=Gelber|first3=Richard|last3=Gilardi}}</ref>

Hypercubane was predicted to exist in a 2014 publication.<ref>{{cite journal|last=Pichierri|first=F.|journal=Chem. Phys. Lett.|date=2014|volume=612|pages=198–202|doi=10.1016/j.cplett.2014.08.032|title= Hypercubane: DFT-based prediction of an ''Oh''-symmetric double-shell hydrocarbon|bibcode=2014CPL...612..198P}}</ref><ref>{{Cite web | url=http://www.compchemhighlights.org/2014/12/hypercubane-dft-based-prediction-of-oh.html |title = Hypercubane: DFT-based prediction of an Oh-symmetric double-shell hydrocarbon}}</ref>

===Persubstituted derivatives=== Octaphenylcubane pre-dates the parent compound. Freedman synthesized it from tetraphenylcyclobutadiene nickel bromide in 1962. It is a sparingly soluble colourless compound that melts at 425–427 °C.<ref name= Biegasiewicz /><ref name=freedman1961 /><ref name=freedman1962 /><ref name=freedman1965 />

Octanitrocubane is a green explosive.

Both heptafluorocubane and octafluorocubane were synthesized in 2022 to study octafluorocubane's unusual electronic structure.<ref>{{cite journal |vauthors=Sugiyama M, Akiyama M, Yonezawa Y, Komaguchi K, Higashi M, Nozaki K, Okazoe T |date=August 2022 |title=Electron in a cube: Synthesis and characterization of perfluorocubane as an electron acceptor |journal=Science |volume=377 |issue=6607 |pages=756–759 |doi=10.1126/science.abq0516 |pmid=35951682 |bibcode=2022Sci...377..756S |s2cid=251515925}}</ref> Single-electron reduction to the radical anion {{chem|C|8|F|8|-}} traps<ref>Pichierri, F. Substituent effects in cubane and hypercubane: a DFT and QTAIM study. ''Theor Chem Acc'' 2017; 136: 114. {{doi|10.1007/s00214-017-2144-5}}</ref> an otherwise-free electron inside the cube, making it the world's smallest box.<ref>{{cite journal |vauthors=Krafft MP, Riess JG |date=August 2022 |title=Perfluorocubane-a tiny electron guzzler |journal=Science |volume=377 |issue=6607 |pages=709 |doi=10.1126/science.adc9195 |pmid=35951708 |bibcode=2022Sci...377..709K |s2cid=251517529|url=https://hal.science/hal-03873082 }}</ref>

===Cubenes and oligo-cubylcubanes=== Despite their orbital strain, two cubenes have been synthesized, and a third analyzed computationally. {{ill|o-Cubene|lt=''ortho''-{{chem name|Cubene}}|qid=Q134578818|s=1}}, produced via lithium-halogen exchange followed by elimination,<ref name=MMisc>{{cite web|website=Cubane|first=B.|last=Muir|publisher=Imperial College London|title=Further topics|url=https://www.ch.ic.ac.uk/local/projects/b_muir/Cubane/Cubanepro/FurtherTopics.html|access-date=22 May 2025|url-status=live|archive-url=https://web.archive.org/web/20240119125713/https://www.ch.ic.ac.uk/local/projects/b_muir/Cubane/Cubanepro/FurtherTopics.html|archive-date=19 January 2024}}</ref> was the most pyramidalized alkene ever made at the time of its first synthesis.<ref>{{cite journal |title= Cubene (1,2-dehydrocubane) |first1= Philip E. |last1= Eaton |first2= Michele |last2= Maggini |journal= J. Am. Chem. Soc. |year= 1988 |volume= 110 |issue= 21 |pages= 7230–7232 |doi= 10.1021/ja00229a057 |bibcode= 1988JAChS.110.7230E }}</ref> In 2026, a new study of cubene was reported by Garg and Houk, showing that cubene has unusually low bond order and undergoes cycloadditions.<ref>{{Cite journal |last=Ding |first=Jiaming |last2=French |first2=Sarah A. |last3=Rivera |first3=Christina A. |last4=Tena Meza |first4=Arismel |last5=Witkowski |first5=Dominick C. |last6=Houk |first6=K. N. |last7=Garg |first7=Neil K. |date=2026-01-21 |title=Hyperpyramidalized alkenes with bond orders near 1.5 as synthetic building blocks |url=https://www.nature.com/articles/s41557-025-02055-9 |journal=Nature Chemistry |language=en |pages=1–10 |doi=10.1038/s41557-025-02055-9 |issn=1755-4349|doi-access=free }}</ref>

''Meta''-{{chem name|cubene}} (1,3-dehydrocubane) is even less stable, and ''para''-{{chem name|cubene}} (1,4-dehydrocubane) probably only exists as a diradical rather than an actual diagonal bond.<ref>{{cite book |title= Strained Hydrocarbons |url= https://archive.org/details/strainedhydrocar00hypo_746 |url-access= limited |editor-first= Helena |editor-last= Dodziuk |chapter= 2.3 A Theoretical Approach to the Study and Design of Prismane Systems |first1= Ruslan M. |last1= Minyaev |first2= Vladimir I. |last2= Minkin |first3= Tatyana N. |last3= Gribanova |publisher= Wiley |year= 2009 |isbn= 9783527627141 |page=55}}</ref> They rapidly undergo nucleophilic addition.<ref name="Cubenes" />

Decomposition of cubenes has enabled chemists to synthesize cubylcubane, as well as higher oligomers.<ref name=Cubenes>{{cite journal |last1=Eaton |first1=Philip E. |title=Cubanes: Starting Materials for the Chemistry of the 1990s and the New Century |journal=Angewandte Chemie International Edition in English |date=1992 |volume=31 |issue=11 |pages=1421–1436 |doi=10.1002/anie.199214211 |language=en |issn=1521-3773}}</ref> Per X-ray diffraction, the central cubane-cubane bond is exceedingly short (1.458 Å), much shorter than the typical C-C single bond (1.578 Å). This is attributed to the fact that the exocyclic orbitals of cubane are ''s''-rich and close to the nucleus.<ref>{{cite journal |last1=Gilardi |first1=Richard. |last2=Maggini |first2=Michele. |last3=Eaton |first3=Philip E. |title=X-ray structures of cubylcubane and 2-tert-butylcubylcubane: short cage-cage bonds |journal=Journal of the American Chemical Society |date=1 October 1988 |volume=110 |issue=21 |pages=7232–7234 |doi=10.1021/ja00229a058 |bibcode=1988JAChS.110.7232G |issn=0002-7863}}</ref>

The ''oligo''-cubylcubanes are rigid molecular rods considered for liquid crystal design. Absent solubilizing groups on the cubane monomer, oligomers with at least 4 units are essentially insoluble, thus scarcely accessible through conventional organic synthesis.<ref>{{cite web|website=Cubane|first=B.|last=Muir|publisher=Imperial College London|title=Applications|at=Polymers|url=https://www.ch.ic.ac.uk/local/projects/b_muir/Cubane/Cubanepro/Applications.html|access-date=22 May 2025|url-status=live|archive-url=https://web.archive.org/web/20240508043615/https://www.ch.ic.ac.uk/local/projects/b_muir/Cubane/Cubanepro/Applications.html|archive-date=8 May 2024}}</ref>

===poly-cubane=== thumb|right|120px|class=skin-invert-image|Diasterane ''poly''-cubane may be synthesized via solid-state polymerization of cubane at 250 °C and high pressure (4–30 GPa) in a diamond anvil cell, and is recoverable at ambient temperature and pressure.<ref name=Huang2020>{{cite journal |last1=Huang |first1=Haw-Tyng |last2=Zhu |first2=Li |last3=Ward |first3=Matthew D. |last4=Wang |first4=Tao |last5=Chen |first5=Bo |last6=Chaloux |first6=Brian L. |last7=Wang |first7=Qianqian |last8=Biswas |first8=Arani |last9=Gray |first9=Jennifer L. |last10=Kuei |first10=Brooke |last11=Cody |first11=George D. |last12=Epshteyn |first12=Albert |last13=Crespi |first13=Vincent H. |last14=Badding |first14=John V. |last15=Strobel |first15=Timothy A. |title=Nanoarchitecture through Strained Molecules: Cubane-Derived Scaffolds and the Smallest Carbon Nanothreads |journal=Journal of the American Chemical Society |date=21 January 2020 |volume=142 |issue=42 |pages=17944–17955 |doi=10.1021/jacs.9b12352 |pmid=31961671 |bibcode=2020JAChS.14217944H |s2cid=210870993 |issn=0002-7863|url=https://par.nsf.gov/servlets/purl/10210835}}</ref> It is a translucent yellow crystalline solid, denser than cubane itself, that is stable up to 300 °C.<ref name=Huang2020/> Provisional structure assignment from powder X-ray diffraction suggests a model for the material that is formally derived from a 1D chain of cubane molecules by breaking two diametrically opposite C–C bonds in each cubane molecule to form a diasterane-based tetraradical, then connecting each such group to the groups directly to its left and right via pairs of C–C bonds.<ref name=Huang2020/>{{rp|at=Figure 2}} It exhibits an exceptionally high refractive index.<ref name=Huang2020/>{{Failed verification|date=March 2026}}

==References== {{reflist|colwidth=30em |refs= <ref name= Biegasiewicz >{{cite journal| last1 = Biegasiewicz | first1 = Kyle | last2 = Griffiths | first2 = Justin | last3 = Savage | first3 = G. Paul | last4 = Tsanakstidis | first4 = John | last5 = Priefer | first5 = Ronny | year = 2015 | title = Cubane: 50 years later | journal = Chemical Reviews| volume = 115 | issue = 14 | pages = 6719–6745 | doi=10.1021/cr500523x | pmid=26102302}}</ref> <ref name="eaton-1964">{{cite journal|title=Cubane|first1=Philip E.|last1=Eaton|first2=Thomas W.|last2=Cole|journal=J. Am. Chem. Soc.|date=1964|volume=86|issue=15|pages=3157–3158|doi=10.1021/ja01069a041|bibcode=1964JAChS..86.3157E }}</ref> <ref name=eaton1964 >{{cite journal|title=The Cubane System|first1=Philip E.|last1=Eaton|first2=Thomas W.|last2=Cole|journal=J. Am. Chem. Soc.|date=1964|volume=86|issue=5|pages=962–964|doi=10.1021/ja01059a072|bibcode=1964JAChS..86..962E }}</ref> <ref name=March>{{cite book|first1=Michael B.|last1=Smith|first2=Jerry|last2=March|title=March's Advanced Organic Chemistry|url=https://archive.org/details/organicchemistry00mich_115|url-access=limited|edition=5th|publisher=John Wiley & Sons|date=2001|page=[https://archive.org/details/organicchemistry00mich_115/page/n1477 1459]|isbn=0-471-58589-0}}</ref> <ref name=kindler>{{cite journal|title=Studien über den Mechanismus chemischer Reaktionen, XXIII. Hydrierungen von Nitrilen unter Verwendung von Terpenen als Wasserstoffdonatoren|first1=K.|last1=Kindler|first2=K.|last2=Lührs|journal=Chem. Ber.|volume=99|date=1966|pages=227–232|doi=10.1002/cber.19660990135}}</ref> <ref name=freedman1961>{{cite journal|title=Tetraphenylcyclobutadiene Derivatives. II.1 Chemical Evidence for the Triplet State|first=H. H.|last=Freedman|journal=J. Am. Chem. Soc.|date=1961|volume=83|issue=9|pages=2195–2196|doi=10.1021/ja01470a037|bibcode=1961JAChS..83.2195F }}</ref> <ref name=freedman1962>{{cite journal|title=Tetraphenylcyclobutadiene Derivatives. IV.1 "Octaphenylcubane"; A Dimer of Tetraphenylcyclobutadiene|first1=H. H.|last1=Freedman|first2=D. R.|last2=Petersen|journal=J. Am. Chem. Soc.|date=1962|volume=84|issue=14|pages=2837–2838|doi=10.1021/ja00873a046|bibcode=1962JAChS..84.2837F }}</ref> <ref name=freedman1965>{{cite journal|title=Structure of the Dimer of tetraphenylcyclobutadiene|first1=G. S.|last1=Pawley|first2=W. N.|last2=Lipscomb|first3=H. H.|last3=Freedman|journal=J. Am. Chem. Soc.|date=1964|volume=86|issue=21|pages=4725–4726|doi=10.1021/ja01075a042|bibcode=1964JAChS..86.4725P }}</ref> }}

==External links== * [http://www.synarchive.com/syn/14 Eaton's cubane synthesis at SynArchive.com] * [http://www.synarchive.com/syn/189 Tsanaktsidis's cubane synthesis at SynArchive.com] * [http://www.ch.ic.ac.uk/local/projects/b_muir/Cubane/Cubanepro/Start.html Cubane chemistry at Imperial College London]

Category:Cubanes Category:Molecular geometry Category:Theoretical chemistry Category:Substances discovered in the 1960s Category:Pentacyclic compounds Category:Cubes Category:Polycyclic nonaromatic hydrocarbons