View source for Buckminsterfullerene

{{Short description|Cage-like allotrope of carbon}}
{{redirect|Buckyball|other uses|Buckyball (disambiguation)}}
{{Chembox
|Watchedfields = changed
|verifiedrevid = 455081104
|Name = Buckminsterfullerene
|ImageFileL1 = Buckminsterfullerene.svg
|ImageFileR1 = Buckminsterfullerene-perspective-3D-balls.png
|ImageFile2 = C60-Fulleren-kristallin.JPG
|PIN = (C<sub>60</sub>-''I''<sub>h</sub>)[5,6]fullerene<ref>{{cite book |author=[[International Union of Pure and Applied Chemistry]] |date=2014 |title=Nomenclature of Organic Chemistry: IUPAC Recommendations and Preferred Names 2013 |publisher=[[Royal Society of Chemistry|The Royal Society of Chemistry]] |pages=325 |doi=10.1039/9781849733069 |isbn=978-0-85404-182-4}}</ref>
|OtherNames = Buckyballs; Fullerene-C<sub>60</sub>; [60]fullerene
|pronounce = {{IPAc-en|ˌ|b|ʌ|k|m|ɪ|n|s|t|ər|ˈ|f|ʊ|l|ə|r|iː|n}}
|Section1 = {{Chembox Identifiers
|InChI = 1/C60/c1-2-5-6-3(1)8-12-10-4(1)9-11-7(2)17-21-13(5)23-24-14(6)22-18(8)28-20(12)30-26-16(10)15(9)25-29-19(11)27(17)37-41-31(21)33(23)43-44-34(24)32(22)42-38(28)48-40(30)46-36(26)35(25)45-39(29)47(37)55-49(41)51(43)57-52(44)50(42)56(48)59-54(46)53(45)58(55)60(57)59
|InChIKey = XMWRBQBLMFGWIX-UHFFFAOYAU
|InChI1 = 1S/C60/c1-2-5-6-3(1)8-12-10-4(1)9-11-7(2)17-21-13(5)23-24-14(6)22-18(8)28-20(12)30-26-16(10)15(9)25-29-19(11)27(17)37-41-31(21)33(23)43-44-34(24)32(22)42-38(28)48-40(30)46-36(26)35(25)45-39(29)47(37)55-49(41)51(43)57-52(44)50(42)56(48)59-54(46)53(45)58(55)60(57)59
|InChIKey1 = XMWRBQBLMFGWIX-UHFFFAOYSA-N
|Beilstein = 5901022
|CASNo_Ref = {{cascite|correct|CAS}}
|CASNo = 99685-96-8
|PubChem = 123591
|ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
|ChemSpiderID = 110185
|ChEBI_Ref = {{ebicite|correct|EBI}}
|ChEBI = 33128
|UNII = NP9U26B839
|StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
|StdInChIKey = XMWRBQBLMFGWIX-UHFFFAOYSA-N
|SMILES = 
c12c3c4c5c2c2c6c7c1c1c8c3c3c9c4c4c%10c5c5c2c2c6c6c%11c7c1c1c7c8c3c3c8c9c4c4c9c%10c5c5c2c2c6c6c%11c1c1c7c3c3c8c4c4c9c5c2c2c6c1c3c42
|StdInChI_Ref = {{stdinchicite|correct|chemspider}}
|StdInChI = 1S/C60/c1-2-5-6-3(1)8-12-10-4(1)9-11-7(2)17-21-13(5)23-24-14(6)22-18(8)28-20(12)30-26-16(10)15(9)25-29-19(11)27(17)37-41-31(21)33(23)43-44-34(24)32(22)42-38(28)48-40(30)46-36(26)35(25)45-39(29)47(37)55-49(41)51(43)57-52(44)50(42)56(48)59-54(46)53(45)58(55)60(57)59
}}
|Section2 = {{Chembox Properties
|C=60
|Appearance = Dark needle-like crystals
|Density = 1.65&nbsp;g/cm<sup>3</sup>
|BoilingPt =
|VaporPressure = 0.4–0.5&nbsp;Pa (T ≈ 800&nbsp;K); 14&nbsp;Pa (T ≈ 900&nbsp;K) <ref>{{Cite journal |last1=Piacente |first1=V. |last2=Gigli |first2=G. |last3=Scardala |first3=P. |last4=Giustini  |first4=A. |last5=Ferro |first5=D. |date=September 1995 |title=Vapor Pressure of {{chem|C|60}} Buckminsterfullerene |url=https://pubs.acs.org/doi/abs/10.1021/j100038a041 |journal=J. Phys. Chem.
 |language=en |volume=99 |issue=38 |pages=14052–14057 |doi=10.1021/j100038a041 |issn=0022-3654|url-access=subscription }}</ref>
| Solubility = insoluble in water
}}
|Section3 = {{Chembox Structure
|CrystalStruct = Face-centered cubic, [[Pearson symbol|cF1924]]
|SpaceGroup = Fm{{overline|3}}m, No.&nbsp;225
|LattConst_a = 1.4154 nm
}}
|Section7 = {{Chembox Hazards
|GHSPictograms = {{GHS07}}
|GHSSignalWord = Warning
|HPhrases = {{H-phrases|315|319|335}}
|PPhrases = {{P-phrases|261|264|271|280|302+352|304+340|305+351+338|312|321|332+313|337+313|362|403+233|405|501}}
}}
}}
{{Nanomaterials}}
'''Buckminsterfullerene''' is a type of [[fullerene]] with the formula {{chem|C|60}}. It has a cage-like fused-ring structure ([[truncated icosahedron]]) made of twenty [[hexagon]]s and twelve [[pentagon]]s, and resembles a [[Ball (association football)|football]]. Each of its 60 [[carbon]] atoms is [[Chemical bond|bonded]] to its three neighbors. 

Buckminsterfullerene is a black solid that dissolves in [[hydrocarbon]] [[Solvent|solvents]] to produce a purple solution. The substance was discovered in 1985 and has received intense study, although few real world applications have been found.

Molecules of buckminsterfullerene (or of fullerenes in general) are commonly nicknamed '''buckyballs'''.<ref>{{cite web |title=Buckyball |url=https://www.oed.com/dictionary/buckyball_n#12769207 |website=Oxford English Dictionary |publisher=Oxford University Press |access-date=13 April 2024}}</ref><ref name="AZoM-2006">{{cite web | title=Buckminsterfullerene and Buckyballs – Definition, Discovery, Structure, Production, Properties and Applications | website=AZoM | date=2006-07-15 | url=https://www.azom.com/article.aspx?ArticleID=3499 }}</ref>

==Occurrence==
Buckminsterfullerene is the most common naturally occurring fullerene.  Small quantities of it can be found in [[soot]].<ref>{{cite journal|doi=10.1038/352139a0|title=Fullerenes {{chem|C|60}} and {{chem|C|70}} in flames |year=1991|last1=Howard|first1=Jack B.|last2=McKinnon|first2=J. Thomas|last3=Makarovsky|first3=Yakov |last4=Lafleur|first4=Arthur L.|last5=Johnson|first5=M. Elaine|journal=Nature|volume=352|issue=6331 |pages=139–141|pmid=2067575 |bibcode=1991Natur.352..139H |s2cid=37159968}}</ref><ref>{{cite journal |doi=10.1016/0008-6223(92)90061-Z|title=Fullerenes synthesis in combustion|year=1992|last1=Howard|first1=J |last2=Lafleur|first2=A|last3=Makarovsky|first3=Y |last4=Mitra|first4=S|last5=Pope|first5=C|last6=Yadav |first6=T|journal=Carbon|volume=30|issue=8|pages=1183–1201|bibcode=1992Carbo..30.1183H }}</ref> 

It also [[List of interstellar and circumstellar molecules|exists in space]]. Neutral {{chem|C|60}} has been observed in [[planetary nebulae]]<ref>{{cite journal|bibcode=2010Sci...329.1180C|doi=10.1126/science.1192035|title=Detection of C60 and C70 in a Young Planetary Nebula|year=2010|last1=Cami|first1=J.|last2=Bernard-Salas|first2=J. |last3=Peeters |first3=E.|last4=Malek|first4=S. E.|journal=Science|volume=329|issue=5996|pages=1180–1182|pmid=20651118 |s2cid=33588270}}</ref> and several types of [[star]].<ref>{{cite journal|bibcode=2012MNRAS.421.3277R |doi=10.1111/j.1365-2966.2012.20552.x |title=Detection of C60 in embedded young stellar objects, a Herbig Ae/Be star and an unusual post-asymptotic giant branch star |year=2012 |last1=Roberts |first1=Kyle R. G. |last2=Smith |first2=Keith T. |last3=Sarre |first3=Peter J. |journal=Monthly Notices of the Royal Astronomical Society |volume=421 |issue=4 |pages=3277–3285 |doi-access=free |arxiv=1201.3542 |s2cid=118739732 }}</ref> The ionised form, {{chem|C|60|+}}, has been identified in the [[interstellar medium]],<ref>{{cite journal|bibcode=2013A&A...550L...4B|doi=10.1051/0004-6361/201220730 |title=Interstellar C60+ |year=2013 |last1=Berné |first1=O. |last2=Mulas |first2=G. |last3=Joblin |first3=C.|author3-link=Christine Joblin |journal=Astronomy & Astrophysics |volume=550 |pages=L4 |arxiv=1211.7252 |s2cid=118684608 }}</ref> where it is the cause of several absorption features known as [[diffuse interstellar band]]s in the near-infrared.<ref>{{cite journal|last1=Maier|first1=J. P.|last2=Gerlich|first2=D.|last3=Holz|first3=M.|last4=Campbell |first4=E. K.|date=July 2015|title=Laboratory confirmation of {{chem|C|60|+}} as the carrier of two diffuse interstellar bands|journal=Nature|volume=523|issue=7560|pages=322–323|doi=10.1038/nature14566 |issn=1476-4687|pmid=26178962|bibcode=2015Natur.523..322C|s2cid=205244293}}</ref> 

==History==
{{Further|Fullerene}}

{{multiple image
|align = left
|image1 = Hkroto.jpg
|width1 = 120
|caption1 = [[Harold Kroto]]
|width2 = 195
|caption2 = [[Richard Smalley]]
}}
[[Image:Football Pallo valmiina-cropped.jpg|thumb|right|160px|Many [[Ball (association football)|football]]s have the same arrangement of polygons as buckminsterfullerene, {{chem|C|60}}.]]
Theoretical predictions of buckminsterfullerene molecules appeared in the late 1960s and early 1970s.<ref name=k363>{{harvnb|Katz|2006|p=363}}</ref><ref>{{Cite journal |last=Osawa |first=E. |year=1970 |title=Superaromaticity |journal=Kagaku |language=Japanese |location=Kyoto |volume=25 |pages=854–863}}</ref><ref>{{Cite journal |last=Jones |first=David E. H. |year=1966 |title=Hollow molecules |journal=New Scientist |issue=32 |pages=245}}</ref><ref name="Smalley-1997">{{Cite journal |last=Smalley |first=Richard E. |date=1997-07-01 |title=Discovering the fullerenes |journal=Reviews of Modern Physics |volume=69 |issue=3 |pages=723–730 |doi=10.1103/RevModPhys.69.723|bibcode=1997RvMP...69..723S |citeseerx=10.1.1.31.7103 }}</ref> It was first generated in 1984 by Eric Rohlfing, Donald Cox, and Andrew Kaldor,<ref name="Smalley-1997" /><ref>{{cite journal|doi=10.1063/1.447994|bibcode=1984JChPh..81.3322R|title=Production and characterization of supersonic carbon cluster beams|journal=Journal of Chemical Physics|volume=81|issue=7|pages=3322|last1=Rohlfing|first1=Eric A|last2=Cox|first2=D. M|last3=Kaldor|first3=A|year=1984}}</ref> using a laser to vaporize carbon in a supersonic [[helium]] beam, although the group did not realize that buckminsterfullerene had been produced. In 1985 their work was repeated by [[Harold Kroto]], [[James R. Heath]], [[Sean C. O'Brien]], [[Robert Curl]], and [[Richard Smalley]] at [[Rice University]], who recognized the structure of {{chem|C|60}} as buckminsterfullerene.<ref name=Kroto />

Concurrent but unconnected to the Kroto-Smalley work, astrophysicists were working with spectroscopists to study infrared emissions from giant red carbon stars.<ref name=Dresselhaus>{{cite book |last1=Dresselhaus |first1=M. S. |author-link1=Mildred Dresselhaus|last2=Dresselhaus |first2=G. |last3=Eklund |first3=P. C. |title=Science of Fullerenes and Carbon Nanotubes |date=1996 |publisher=Academic Press |location=San Diego, CA |isbn=978-012-221820-0}}</ref><ref>{{Cite journal |last=Herbig |first=E. |year=1975 |title=The diffuse interstellar bands. IV – the region 4400-6850 A |journal=Astrophys. J. |volume=196 |page=129 |bibcode=1975ApJ...196..129H |doi=10.1086/153400}}</ref><ref>{{cite journal |last1=Leger |first1=A. |title=Remarkable candidates for the carrier of the diffuse interstellar bands: {{chem|C|60|+}} and other polyhedral carbon ions |last2=d'Hendecourt |first2=L. |last3=Verstraete |first3=L. |last4=Schmidt |first4=W. |journal=Astron. Astrophys. |year=1988 |volume=203 |issue=1 |page=145|bibcode = 1988A&A...203..145L}}</ref> Smalley and team were able to use a laser vaporization technique to create carbon clusters which could potentially emit infrared at the same wavelength as had been emitted by the red carbon star.<ref name=Dresselhaus/><ref>{{Cite journal |last1=Dietz |first1=T. G. |last2=Duncan |first2=M. A. |last3=Powers |first3=D. E. |last4=Smalley |first4=R. E. |year=1981 |title=Laser production of supersonic metal cluster beams |journal=J. Chem. Phys. |volume=74 |issue=11 |page=6511 |bibcode=1981JChPh..74.6511D |doi=10.1063/1.440991}}</ref> Hence, the inspiration came to Smalley and team to use the laser technique on graphite to generate fullerenes.

Using [[laser]] [[evaporation]] of [[graphite]] the Smalley team found C<sub>''n''</sub> clusters (where {{nowrap|''n'' > 20}} and even) of which the most common were {{chem|C|60}} and {{chem|C|70}}. A solid rotating graphite disk was used as the surface from which carbon was vaporized using a laser beam creating hot plasma that was then passed through a stream of high-density helium gas.<ref name=Kroto>{{cite journal |last1=Kroto |first1=H. W. |last2=Health |first2=J. R. |last3=O'Brien |first3=S. C. |last4=Curl |first4=R. F. |last5=Smalley |first5=R. E. |title={{chem|C|60}}: Buckminsterfullerene |journal=[[Nature (journal)|Nature]] |year=1985 |volume=318 |pages=162–163 |doi=10.1038/318162a0 |bibcode=1985Natur.318..162K |issue=6042|s2cid=4314237 }}</ref> The carbon [[chemical species|species]]  were subsequently cooled and ionized resulting in the formation of clusters. Clusters ranged in molecular masses, but Kroto and Smalley found predominance in a {{chem|C|60}} cluster that could be enhanced further by allowing the plasma to react longer. They also discovered that {{chem|C|60}} is a cage-like molecule, a regular [[truncated icosahedron]].<ref name="Dresselhaus"/><ref name="Kroto"/>

The experimental evidence, a strong peak at 720 [[Dalton (unit)|dalton]]s, indicated that a carbon molecule with 60 carbon atoms was forming, but provided no structural information. The research group concluded after reactivity experiments, that the most likely structure was a spheroidal molecule. The idea was quickly rationalized as the basis of an [[icosahedral]] [[symmetry]] closed cage structure.<ref name=k363/>

Kroto, Curl, and Smalley were awarded the 1996 [[Nobel Prize in Chemistry]] for their roles in the discovery of buckminsterfullerene and the related class of molecules, the [[fullerene]]s.<ref name=k363/>

In 1989 physicists [[Wolfgang Krätschmer]], [[Konstantinos Fostiropoulos]], and [[Donald Huffman|Donald R. Huffman]] observed unusual optical absorptions in thin films of carbon dust (soot). The soot had been generated by an arc-process between two graphite [[electrodes]] in a helium atmosphere where the electrode material evaporates and condenses forming soot in the quenching atmosphere. Among other features, the [[Infrared spectroscopy|IR spectra]] of the soot showed four discrete bands in close agreement to those proposed for {{chem|C|60}}.<ref>{{cite book | last1=Krätschmer | first1=W. | last2=Fostiropoulos | first2=K. | last3=Huffman | first3=D. R. | title=Dusty Objects in the Universe | chapter=Search for the UV and IR Spectra of {{chem|C|60}} in Laboratory-Produced Carbon Dust | publisher=Springer Netherlands | publication-place=Dordrecht | volume=165 | date=1990 | isbn=978-94-010-6782-9 | doi=10.1007/978-94-009-0661-7_11 | pages=89–93}}</ref><ref>{{cite journal | doi=10.1016/0009-2614(90)87109-5 | volume=170 | issue=2–3 | title=The infrared and ultraviolet absorption spectra of laboratory-produced carbon dust: evidence for the presence of the {{chem|C|60}} molecule | year=1990 | journal=Chemical Physics Letters | pages=167–170 | last1 = Krätschmer | first1 = W.| bibcode=1990CPL...170..167K | doi-access=free}}</ref>

Another paper on the characterization and verification of the molecular structure followed on in the same year (1990) from their thin film experiments, and detailed also the extraction of an evaporable as well as [[benzene]]-soluble material from the arc-generated soot. This extract had [[Transmission electron microscopy|TEM]] and [[X-ray]] crystal analysis consistent with arrays of spherical {{chem|C|60}} molecules, approximately 1.0&nbsp;nm in [[Van der Waals radius|van der Waals diameter]]<ref name="buckminsterfullerene3"/> as well as the expected molecular mass of 720&nbsp;Da for {{chem|C|60}} (and 840&nbsp;Da for {{chem|C|70}}) in their [[mass spectroscopy|mass spectra]].<ref>{{Cite journal |doi = 10.1038/347354a0|title = Solid {{chem|C|60}}: A new form of carbon|journal = Nature|volume = 347|issue = 6291|pages = 354–358|year = 1990|last1 = Krätschmer|first1 = W.|last2 = Lamb|first2 = Lowell D.|last3 = Fostiropoulos|first3 = K.|last4 = Huffman|first4 = Donald R.|bibcode = 1990Natur.347..354K|s2cid = 4359360}}</ref> The method was simple and efficient to prepare the material in gram amounts per day (1990) which has boosted the fullerene research and is even today applied for the commercial production of fullerenes.

The discovery of practical routes to {{chem|C|60}} led to the exploration of a new field of chemistry involving the study of fullerenes.

===Etymology===
The discoverers of the [[allotropy|allotrope]] named the newfound molecule after American architect [[Buckminster Fuller|R. Buckminster Fuller]], who designed many [[geodesic dome]] structures that look similar to {{chem|C|60}} and who had died in 1983, the year before discovery.<ref name=k363/> Another common name for buckminsterfullerene is "buckyballs".<ref>{{cite web |title=What is a geodesic dome? |url=https://exhibits.stanford.edu/bucky/feature/what-is-a-geodesic-dome |website=R. Buckminster Fuller Collection: Architect, Systems Theorist, Designer, and Inventor |date=6 April 2017 |publisher=Stanford University |access-date=10 June 2019 |archive-date=12 January 2020 |archive-url=https://web.archive.org/web/20200112232718/https://exhibits.stanford.edu/bucky/feature/what-is-a-geodesic-dome |url-status=live }}</ref><ref name="AZoM-2006"/>

==Synthesis==
Soot is produced by laser ablation of graphite or [[pyrolysis]] of [[aromatic hydrocarbon]]s. Fullerenes are extracted from the soot with organic solvents using a [[Soxhlet extractor]].<ref>{{cite book|last1=Girolami |first1=G. S.|last2= Rauchfuss|first2= T. B. |last3=Angelici|first3= R. J.|author3-link=Robert Angelici|title= Synthesis and Teknique in Inorganic Chemistry|publisher= University Science Books|location= Mill Valley, CA|date= 1999|isbn=978-0935702484}}</ref> This step yields a solution containing up to 75% of {{chem|C|60}}, as well as other fullerenes. These fractions are separated using [[chromatography]].<ref>{{harvnb|Katz|2006|pp=369–370}}</ref> Generally, the fullerenes are dissolved in a hydrocarbon or halogenated hydrocarbon and separated using alumina columns.<ref>{{cite book |last1=Shriver |last2=Atkins |title=Inorganic Chemistry |edition=Fifth |publisher=W. H. Freeman |location=New York |year=2010 |page=356 |isbn=978-0-19-923617-6 }}</ref>

Synthesis using the techniques of "classical [[organic synthesis|organic chemistry]]" is possible, but not economic.<ref><!--As cited in 10.1002/chem.200501611, fn. 65-->{{multiref|M.M. Boorum, Y.V. Vasil'ev, T. Drewello, and L.T. Scott (2001), in ''Science'' 294, pp.&nbsp;828&ndash;.|L.T. Scott, M.M. Boorum, B.J. McMahon, S. Hagen, J. Mack, J. Blank, H. Wegner, and A. de Meijere (2002), in ''Science'' 295, pp.&nbsp;1500&ndash;.|L.T. Scott (2004), in ''Angew. Chem.'' 116, pp.&nbsp;5102&ndash;; translated in ''Angew. Chem. Int. Ed.'' 43, pp.&nbsp;4994&ndash;.}}</ref>

==Structure==
Buckminsterfullerene is a [[truncated icosahedron]] with 60 [[Vertex (geometry)|vertices]], 32 faces (20 hexagons and 12 pentagons where no pentagons share a vertex), and 90 edges (60 edges between 5-membered & 6-membered rings and 30 edges are shared between 6-membered & 6-membered rings), with a carbon atom at the vertices of each polygon and a bond along each polygon edge. The [[van der Waals diameter]] of a {{chem|C|60}} molecule is about 1.01&nbsp;[[nanometers]] (nm). The nucleus to nucleus diameter of a {{chem|C|60}} molecule is about 0.71&nbsp;nm. The {{chem|C|60}} molecule has two bond lengths. The 6:6 ring bonds (between two hexagons) can be considered "[[double bond]]s" and are shorter than the 6:5 bonds (between a hexagon and a pentagon). Its average bond length is 0.14&nbsp;nm. Each carbon atom in the structure is bonded covalently with 3 others.<ref>{{harvnb|Katz|2006|p=364}}</ref> A carbon atom in the {{chem|C|60}} can be substituted by a [[nitrogen]] or [[boron]] atom yielding a {{chem|C|59|N}} or {{chem|C|59|B}} respectively.<ref>{{harvnb|Katz|2006|p=374}}</ref>

[[File:Buckball-electronic-str en.svg|thumb|Energy level diagram for {{chem|C|60}} under "ideal" spherical (left) and "real" icosahedral symmetry (right).]]

==Properties==
{| class=wikitable
|+ Orthogonal projections
|-
!Centered by
!Vertex
!Edge<br>5–6
!Edge<br>6–6
!Face<br>Hexagon
!Face<br>Pentagon
|-
!Image
|[[File:Dodecahedron t12 v.png|120px]]
|[[File:Dodecahedron t12 e56.png|120px]]
|[[File:Dodecahedron t12 e66.png|120px]]
|[[File:Icosahedron t01 A2.png|120px]]
|[[File:Icosahedron t01 H3.png|120px]]
|- align=center
!Projective<br>symmetry
| [2]
| [2]
| [2]
| [6]
| [10]
|}
For a time buckminsterfullerene was the largest{{quantify|largest in which way? C60 fullerene is still heavier than the pthalo dye and occupies more space in 3 dimensions so a metric is needed|date=April 2025}} known molecule observed to exhibit [[wave–particle duality]].<ref>
{{cite journal |year = 1999 |title = Wave–particle duality of {{chem|C|60}} |journal = [[Nature (journal)|Nature]] |volume = 401 |issue = 6754 |pages = 680–682 |doi = 10.1038/44348 |pmid = 18494170| bibcode = 1999Natur.401..680A |last1 = Arndt |first1 = Markus |last2 = Nairz |first2 = Olaf |last3 = Vos-Andreae |first3 = Julian |last4 = Keller |first4 = Claudia |last5 = Van Der Zouw |first5 = Gerbrand |last6 = Zeilinger |first6 = Anton|s2cid = 4424892}}</ref> In 2020 the dye molecule [[phthalocyanine]] exhibited the duality that is more famously attributed to light, electrons and other small particles and molecules.<ref>{{Cite news | title = Wave-particle duality in action—big molecules surf on their own waves | last = Lee | first = Chris | url = https://arstechnica.com/science/2020/07/wave-particle-duality-in-action-big-molecules-surf-on-their-own-waves/ | work = [[Ars Technica]] | date = 2020-07-21 |access-date= 26 September 2021 | archive-date = 2021-09-26 | archive-url = https://web.archive.org/web/20210926144828/https://arstechnica.com/science/2020/07/wave-particle-duality-in-action-big-molecules-surf-on-their-own-waves/ | url-status = live}}</ref>

===Solution===
[[File:C60 Fullerene solution.jpg|thumb|Dilute solution of {{chem|C|60}} in an aromatic solvent]]

{| align= "left" class="wikitable" style="margin-right:10px"
|+ Solubility of {{chem|C|60}}<ref>
{{cite journal |last1 = Beck|first1 = Mihály T. |last2 = Mándi|first2 = Géza |year = 1997 |title = Solubility of {{chem|C|60}} |journal = Fullerenes, Nanotubes and Carbon Nanostructures |volume = 5|pages = 291–310 |doi = 10.1080/15363839708011993 |issue = 2}}</ref><ref>{{cite journal |last1 = Bezmel'nitsyn|first1 = V. N. |last2 = Eletskii|first2 = A. V. |last3 = Okun'|first3 = M. V. |year = 1998 |title = Fullerenes in solutions |journal = [[Physics-Uspekhi]] |volume = 41|pages = 1091–1114 |doi = 10.1070/PU1998v041n11ABEH000502| bibcode = 1998PhyU...41.1091B |issue = 11 |s2cid = 250785669}}</ref><ref>
{{cite journal |year = 1993 |title = Solubility of fullerene ({{chem|C|60}}) in a variety of solvents |journal = [[Journal of Physical Chemistry]] |volume = 97|pages = 3379–3383 |doi = 10.1021/j100115a049 |issue = 13 |last1 = Ruoff |first1 = R. S. |last2 = Tse |first2 = Doris S. |last3 = Malhotra |first3 = Ripudaman |last4 = Lorents |first4 = Donald C.}}</ref>

!Solvent !!Solubility<br>(g/L)
|-
| [[1-chloronaphthalene]]
| 51
|-
| [[1-methylnaphthalene]]
| 33
|-
| [[1,2-dichlorobenzene]]
| 24
|-
| [[1,2,4-trimethylbenzene]]
| 18
|-
| [[tetrahydronaphthalene]]
| 16
|-
| [[carbon disulfide]]
| 8
|-
| [[1,2,3-tribromopropane]]
| 8
|-
| [[xylene]]
| 5
|-
| [[bromoform]]
| 5
|-
| [[cumene]]
| 4
|-
| [[toluene]]
| 3
|-
| [[benzene]]
| 1.5
|-
| [[carbon tetrachloride]]
| 0.447
|-
| [[chloroform]]
| 0.25
|-
| [[hexane]]
| 0.046
|-
| [[cyclohexane]]
| 0.035
|-
| [[tetrahydrofuran]]
| 0.006
|-
| [[acetonitrile]]
| 0.004
|-
| [[methanol]]
| 0.00004
|-
| [[water]]
| 1.3&nbsp;×&nbsp;10<sup>−11</sup>
|-
| [[pentane]]
| 0.004
|-
| [[octane]]
| 0.025
|-
| [[isooctane]]
| 0.026
|-
| [[decane]]
| 0.070
|-
| [[dodecane]]
| 0.091
|-
| [[tetradecane]]
| 0.126
|-
| [[dioxane]]
| 0.0041
|-
| [[mesitylene]]
| 0.997
|-
| [[dichloromethane]]
| 0.254
|}

[[File:UV-Vis C60.jpg|thumb|Optical absorption spectrum of {{chem|C|60}} solution, showing diminished absorption for the blue (~450&nbsp;nm) and red (~700&nbsp;nm) light that results in the purple color.]]
Fullerenes are sparingly soluble in aromatic [[solvent]]s and [[carbon disulfide]], but insoluble in water. Solutions of pure {{chem|C|60}} have a deep purple color which leaves a brown residue upon evaporation. The reason for this color change is the relatively narrow energy width of the band of molecular levels responsible for green light absorption by individual {{chem|C|60}} molecules. Thus individual molecules transmit some blue and red light resulting in a purple color. Upon drying, intermolecular interaction results in the overlap and broadening of the energy bands, thereby eliminating the blue light transmittance and causing the purple to brown color change.<ref name="Dresselhaus" />

{{chem|C|60}} crystallises with some solvents in the lattice ("solvates"). For example, crystallization of {{chem|C|60}} from [[benzene]] solution yields triclinic crystals with the formula {{chem2|C60·4C6H6}}. Like other solvates, this one readily releases benzene to give the usual face-centred cubic {{chem|C|60}}. Millimeter-sized crystals of {{chem|C|60}} and {{chem|C|70}} can be grown from solution both for solvates and for pure fullerenes.<ref>
{{cite journal |last = Talyzin|first = A. V. |year = 1997 |title = Phase Transition C<sub>60</sub>−C<sub>60</sub>*4C<sub>6</sub>H<sub>6</sub> in Liquid Benzene |journal = [[Journal of Physical Chemistry B]] |volume = 101|pages = 9679–9681 |doi = 10.1021/jp9720303 |issue = 47
}}</ref><ref>{{cite journal |last1 = Talyzin|first1 = A. V. |last2 = Engström|first2 = I. |year = 1998 |title = C70 in Benzene, Hexane, and Toluene Solutions |journal = Journal of Physical Chemistry B |volume = 102|pages = 6477–6481 |doi = 10.1021/jp9815255 |issue = 34}}</ref>

===Solid===
[[Image:C60-Fulleren-kristallin.JPG|thumb|Micrograph of {{chem|C|60}}.]]
[[File:Fullerite structure.jpg|thumb|Packing of {{chem|C|60}} in crystal.]]
In solid buckminsterfullerene, the {{chem|C|60}} molecules adopt the fcc ([[face-centered cubic]]) motif. They start rotating at about −20&nbsp;°C. This change is associated with a first-order phase transition to an fcc structure and a small, yet abrupt increase in the lattice constant from 1.411 to 1.4154&nbsp;nm.<ref name=k372>{{harvnb|Katz|2006|p=372}}</ref>

{{chem|C|60}} solid is as soft as [[graphite]], but when compressed to less than 70% of its volume it transforms into a [[superhard materials|superhard]] form of [[diamond]] (see [[aggregated diamond nanorod]]). {{chem|C|60}} films and solution have strong non-linear optical properties; in particular, their optical absorption increases with light intensity (saturable absorption).

{{chem|C|60}} forms a brownish solid with an optical absorption threshold at ≈1.6&nbsp;eV.<ref>{{harvnb|Katz|2006|p=361}}</ref> It is an n-type [[semiconductor]] with a low activation energy of 0.1–0.3&nbsp;eV; this conductivity is attributed to intrinsic or oxygen-related defects.<ref>{{harvnb|Katz|2006|p=379}}</ref> Fcc {{chem|C|60}} contains voids at its octahedral and tetrahedral sites which are sufficiently large (0.6 and 0.2&nbsp;nm respectively) to accommodate impurity atoms. When alkali metals are [[Doping (semiconductor)|doped]] into these voids, {{chem|C|60}} converts from a semiconductor into a conductor or even superconductor.<ref name=k372/><ref>{{harvnb|Katz|2006|p=381}}</ref>

==Chemical reactions and properties==
{{chem|C|60}} undergoes six reversible, one-electron reductions, ultimately generating {{chem|C|60|6-}}. Its [[oxidation]] is irreversible. The first reduction occurs at ≈−1.0&nbsp;[[Volt|V]] ([[Ferrocene|Fc]]/{{chem|Fc|+}}), showing that {{chem|C|60}} is a reluctant electron acceptor.  {{chem|C|60}} tends to avoid having double bonds in the pentagonal rings, which makes electron [[delocalization]] poor, and results in {{chem|C|60}} not being "[[superaromatic]]". {{chem|C|60}} behaves like an electron deficient [[alkene]]. For example, it reacts with some nucleophiles.<ref name="buckminsterfullerene3"/><ref name=Reed/>

=== Hydrogenation ===
{{chem|C|60}} exhibits a small degree of aromatic character, but it still reflects localized double and single C–C bond characters. Therefore, {{chem|C|60}} can undergo addition with hydrogen to give polyhydrofullerenes. {{chem|C|60}} also undergoes [[Birch reduction]]. For example, {{chem|C|60}} reacts with lithium in liquid ammonia, followed by ''tert''-butanol to give a mixture of polyhydrofullerenes such as {{chem2|C60H18}}, {{chem2|C60H32}}, {{chem2|C60H36}}, with {{chem2|C60H32}} being the dominating product. This mixture of polyhydrofullerenes can be re-oxidized by [[2,3-Dichloro-5,6-dicyano-1,4-benzoquinone|2,3-dichloro-5,6-dicyano-1,4-benzoquinone]] to give {{chem|C|60}} again.

A selective hydrogenation method exists. Reaction of {{chem|C|60}} with 9,9′,10,10′-dihydroanthracene under the same conditions, depending on the time of reaction, gives {{chem2|C60H32}} and {{chem2|C60H18}} respectively and selectively.<ref name="InorgChem">{{cite book| title = Inorganic Chemistry| edition = 3rd| chapter = Chapter 14: The group 14 elements| author1 = Catherine E. Housecroft| author2 = Alan G. Sharpe| publisher = Pearson| year = 2008| isbn = 978-0-13-175553-6}}</ref>

===Halogenation===
Addition of [[fluorine]], [[chlorine]], and [[bromine]] occurs for {{chem|C|60}}. Fluorine atoms are small enough for a 1,2-addition, while {{chem|Cl|2}} and {{chem|Br|2}} add to remote C atoms due to [[steric factor]]s. For example, in {{chem2|C60Br8}} and {{chem2|C60Br24}}, the Br atoms are in 1,3- or 1,4-positions with respect to each other. Under various conditions a vast number of halogenated derivatives of {{chem|C|60}} can be produced, some with an extraordinary selectivity on one or two isomers over the other possible ones. Addition of fluorine and chlorine usually results in a flattening of the {{chem|C|60}} framework into a drum-shaped molecule.<ref name="InorgChem" />

===Addition of oxygen atoms===
Solutions of {{chem|C|60}} can be oxygenated to the [[epoxide]] {{chem2|C60O}}. Ozonation of {{chem|C|60}} in 1,2-xylene at 257K gives an intermediate ozonide {{chem2|C60O3}}, which can be decomposed into 2 forms of {{chem2|C60O}}. Decomposition of {{chem2|C60O3}} at 296&nbsp;K gives the epoxide, but photolysis gives a product in which the O atom bridges a 5,6-edge.<ref name="InorgChem" />

[[File:Addition of O atom into C60 Scheme.png|none|300px]]

===Cycloadditions===
The [[Diels–Alder reaction]] is commonly employed to functionalize {{chem|C|60}}. Reaction of {{chem|C|60}} with appropriate substituted diene gives the corresponding adduct.

The Diels–Alder reaction between {{chem|C|60}} and 3,6-diaryl-1,2,4,5-tetrazines affords{{chem|C|62}}. The {{chem|C|62}} has the structure in which a four-membered ring is surrounded by four six-membered rings.

[[File:3D structure of C62 derivative from C60 update.jpg|thumb|A {{chem|C|62}} derivative {{chem2|[C62(C6H5\-4\-Me)2]}} synthesized from {{chem|C|60}} and 3,6-bis(4-methylphenyl)-3,6-dihydro-1,2,4,5-tetrazine]]

The {{chem|C|60}} molecules can also be coupled through a [2+2] [[cycloaddition]], giving the dumbbell-shaped compound {{chem|C|120}}. The coupling is achieved by high-speed vibrating milling of {{chem|C|60}} with a catalytic amount of [[potassium cyanide|KCN]]. The reaction is reversible as {{chem|C|120}} dissociates back to two {{chem|C|60}} molecules when heated at {{convert|450|K}}. Under high pressure and temperature, repeated [2+2] cycloaddition between {{chem|C|60}} results in polymerized fullerene chains and networks. These polymers remain stable at ambient pressure and temperature once formed, and have remarkably interesting electronic and magnetic properties, such as being [[ferromagnetism|ferromagnetic]] above room temperature.<ref name="InorgChem" />

===Free radical reactions===
Reactions of {{chem|C|60}} with [[free radicals]] readily occur. When {{chem|C|60}} is mixed with a disulfide RSSR, the radical {{chem2|C60SR•}} forms spontaneously upon irradiation of the mixture.

Stability of the radical species {{chem2|C60Y^{•} }} depends largely on [[steric factor]]s of Y. When ''tert''-butyl halide is photolyzed and allowed to react with {{chem|C|60}}, a reversible inter-cage C–C bond is formed:<ref name="InorgChem" />

[[File:Free radical reaction of fullerene with tert-butyl radical.png|none|600px]]

===Cyclopropanation (Bingel reaction)===
Cyclopropanation (the [[Bingel reaction]]) is another common method for functionalizing {{chem|C|60}}. Cyclopropanation of {{chem|C|60}} mostly occurs at the junction of 2 hexagons due to steric factors.

The first cyclopropanation was carried out by treating the β-bromomalonate with {{chem|C|60}} in the presence of a base. Cyclopropanation also occur readily with [[diazomethane]]s. For example, diphenyldiazomethane reacts readily with {{chem|C|60}} to give the compound {{chem2|C61Ph2}}.<ref name="InorgChem" /> [[Phenyl-C61-butyric acid methyl ester|Phenyl-{{chem|C|61}}-butyric acid methyl ester]] derivative prepared through cyclopropanation has been studied for use in [[organic solar cells]].

===Redox reactions===
===={{chem|C|60}} anions====
{{See also|Fullerides}}
The [[LUMO]] in {{chem|C|60}} is triply degenerate, with the [[HOMO]]–[[LUMO]] separation relatively small. This small gap suggests that reduction of {{chem|C|60}} should occur at mild potentials leading to fulleride anions, {{chem2|[C60]^{''n''}−}} (''n''&nbsp;=&nbsp;1–6). The midpoint potentials of 1-electron reduction of buckminsterfullerene and its anions is given in the table below:

{| class="wikitable"
! colspan=2|Reduction potential of {{chem|C|60}} at 213&nbsp;K
|-
! Half-reaction !! ''E''° (V)
|-
| {{chem2|C60 + e− ⇌ C60-}} || −0.169
|-
| {{chem2|C60- + e− ⇌ C60(2-)}} || −0.599
|-
| {{chem2|C60(2-) + e− ⇌ C60(3-)}} || −1.129
|-
| {{chem2|C60(3-) + e− ⇌ C60(4-)}} || −1.579
|-
| {{chem2|C60(4-) + e− ⇌ C60(5-)}} || −2.069
|-
| {{chem2|C60(5-) + e− ⇌ C60(6-)}} || −2.479
|}

{{chem|C|60}} forms a variety of [[charge-transfer complexes]], for example with [[tetrakis(dimethylamino)ethylene]]:
:{{chem2|C60 + C2(NMe2)4 → [C2(NMe2)4]+[C60]-}}
This salt exhibits [[ferromagnetism]] at 16&nbsp;K.

===={{chem|C|60}} cations====
{{chem|C|60}} oxidizes with difficulty. Three reversible oxidation processes have been observed by using [[cyclic voltammetry]] with ultra-dry [[methylene chloride]] and a supporting electrolyte with extremely high oxidation resistance and low nucleophilicity, such as {{chem2|[^{n}Bu4N] [AsF6]}}.<ref name=Reed>{{cite journal |doi=10.1021/cr980017o|title=Discrete Fulleride Anions and Fullerenium Cations|year=2000|last1=Reed|first1=Christopher A.|last2=Bolskar|first2=Robert D.|journal=Chemical Reviews|volume=100|issue=3|pages=1075–1120|pmid=11749258 |s2cid=40552372 |url=https://escholarship.org/uc/item/60b5m71z}}</ref>

{| class="wikitable"
! colspan=2|Reduction potentials of {{chem|C|60}} oxidation at low temperatures
|-
! Half-reaction !! ''E''° (V)
|-
| {{chem2|C60 ⇌ C60+}} || +1.27
|-
| {{chem2|C60+ ⇌ C60(2+)}} || +1.71
|-
| {{chem2|C60(2+) ⇌ C60(3+)}} || +2.14
|}

===Metal complexes===
{{main|Fullerene ligand}}
{{chem|C|60}} forms complexes akin to the more common alkenes. Complexes have been reported [[molybdenum]], [[tungsten]], [[platinum]], [[palladium]], [[iridium]], and [[titanium]].  The pentacarbonyl species are produced by [[photochemical reaction]]s.

: {{chem2|M(CO)6 + C60 → M(\h{2}C60)(CO)5 + CO}} (M = Mo, W)

In the case of platinum complex, the labile ethylene ligand is the leaving group in a thermal reaction:
: {{chem2|Pt(\h{2}C2H4)(PPh3)2 + C60 → Pt(\h{2}C60)(PPh3)2 + C2H4}}

[[Titanocene]] complexes have also been reported:
: {{chem2|(\h{5}[[Cyclopentadienyl|Cp]])2Ti(\h{2}(CH3)3SiC≡CSi(CH3)3) + C60 → (\h{5}Cp)2Ti(\h{2}C60) + (CH3)3SiC≡CSi(CH3)3}}

Coordinatively unsaturated precursors, such as [[Vaska's complex]], for [[adduct]]s with {{chem|C|60}}:

: {{chem2|''trans''\-Ir(CO)Cl(PPh3)2 + C60 → Ir(CO)Cl(\h{2}C60)(PPh3)2}}

One such iridium complex, {{chem2|[Ir(\h{2}C60)(CO)Cl(Ph2CH2C6H4OCH2Ph)2]}} has been prepared where the metal center projects two electron-rich 'arms' that embrace the {{chem|C|60}} guest.<ref name="SupraChem">{{cite book| title = Supramolecular Chemistry| edition = 2nd|author1=Jonathan W. Steed |author2=Jerry L. Atwood |name-list-style=amp | publisher = Wiley| year = 2009| isbn = 978-0-470-51233-3}}</ref>

===Endohedral fullerenes===
{{main|Endohedral fullerene|Endohedral hydrogen fullerene}}

Metal atoms or certain small molecules such as {{chem|H|2}} and noble gas can be encapsulated inside the {{chem|C|60}} cage. These endohedral fullerenes are usually synthesized by doping in the metal atoms in an arc reactor or by laser evaporation. These methods gives low yields of endohedral fullerenes, and a better method involves the opening of the cage, packing in the atoms or molecules, and closing the opening using certain [[organic reactions]]. This method, however, is still immature and only a few species have been synthesized this way.<ref>{{cite journal | last1 = Rodríguez-Fortea | first1 = Antonio | last2 = Balch | first2 = Alan L. | last3 = Poblet | first3 = Josep M. | year = 2011 | title = Endohedral metallofullerenes: a unique host–guest association | journal = Chem. Soc. Rev. | volume = 40 | issue = 7| pages = 3551–3563 | doi = 10.1039/C0CS00225A | pmid = 21505658}}</ref>

Endohedral fullerenes show distinct and intriguing chemical properties that can be completely different from the encapsulated atom or molecule, as well as the fullerene itself. The encapsulated atoms have been shown to perform circular motions inside the {{chem|C|60}} cage, and their motion has been followed using [[NMR spectroscopy]].<ref name="SupraChem" />

==Potential applications in technology==
The optical absorption properties of {{chem|C|60}} match the solar spectrum in a way that suggests that {{chem|C|60}}-based films could be useful for photovoltaic applications. Because of its high [[electron affinity|electronic affinity]]<ref>{{cite journal|last1=Ryuichi|first1=Mitsumoto|title=Electronic Structures and Chemical Bonding of Fluorinated Fullerenes Studied|journal=J. Phys. Chem. A|date=1998 |volume=102|issue=3|pages=552–560 |doi=10.1021/jp972863t|bibcode=1998JPCA..102..552M}}</ref> it is one of the most common [[electron acceptor]]s used in donor/acceptor based solar cells. Conversion efficiencies up to 5.7% have been reported in {{chem|C|60}}–polymer cells.<ref>{{Cite journal |last1=Shang|first1=Yuchen|last2=Liu|first2=Zhaodong|last3=Dong|first3=Jiajun|last4=Yao|first4=Mingguang |last5=Yang|first5=Zhenxing|last6=Li|first6=Quanjun |last7=Zhai|first7=Chunguang|last8=Shen|first8=Fangren |last9=Hou|first9=Xuyuan|last10=Wang|first10=Lin|last11=Zhang|first11=Nianqiang|date=November 2021 |title=Ultrahard bulk amorphous carbon from collapsed fullerene |url=https://www.nature.com/articles/s41586-021-03882-9|journal=Nature|volume=599 |issue=7886|pages=599–604|doi=10.1038/s41586-021-03882-9|pmid=34819685 |bibcode=2021Natur.599..599S |s2cid=244643471 |issn=1476-4687|access-date=2021-11-26|url-status=live|archive-date=2021-11-26|archive-url=https://web.archive.org/web/20211126104002/https://www.nature.com/articles/s41586-021-03882-9|url-access=subscription}}</ref>

{{Further|topic=the basic polymer of the {{chem|C|60}} monomer group|Polyfullerene}}

==Potential applications in health==
{{Main|Health and safety hazards of nanomaterials|Toxicology of carbon nanomaterials}}
=== Ingestion and risks ===
{{chem|C|60}} is sensitive to light,<ref name="Taylor-1991" /> so leaving {{chem|C|60}} under light exposure causes it to degrade, becoming dangerous. The ingestion of {{chem|C|60}} solutions that have been exposed to light could lead to developing cancer (tumors).<ref name="Grohn, Kristopher J.-2021">{{Cite web|last=Grohn, Kristopher J.|title=Comp grad leads research|url=http://weyburnreview.com/news/local-news/comp-grad-leads-research-1.2261882|url-status=live|website=WeyburnReview |access-date=2021-04-17|archive-date=2021-04-17|archive-url=https://web.archive.org/web/20210417041410/https://www.weyburnreview.com/news/local-news/comp-grad-leads-research-1.2261882}}</ref><ref name="Grohn-2021" /> So the management of {{chem|C|60}} products for human ingestion requires cautionary measures<ref name="Grohn-2021" /> such as: elaboration in very dark environments, encasing into bottles of great opacity, and storing in dark places, and others like consumption under low light conditions and using labels to warn about the problems with light.

Solutions of {{chem|C|60}} dissolved in olive oil or water, as long as they are preserved from light, have been found nontoxic to rodents.<ref name="Baati-2012">{{cite journal|last1=Baati|first1=Tarek|last2=Moussa|first2=Fathi|date=June 2012|title=The prolongation of the lifespan of rats by repeated oral administration of [60]fullerene|journal=Biomaterials|volume=33|issue=19|pages=4936–4946|doi=10.1016/j.biomaterials.2012.03.036|pmid=22498298}}<!--|access-date=June 2012--></ref>

Otherwise, a study found that {{chem|C|60}} remains in the body for a longer time than usual, especially in the liver, where it tends to be accumulated, and therefore has the potential to induce detrimental health effects.<ref>{{cite journal | pmc=7005847 | year=2019 | last1=Shipkowski | first1=K. A. | last2=Sanders | first2=J. M. | last3=McDonald | first3=J. D. | last4=Walker | first4=N. J. | last5=Waidyanatha | first5=S. | title=Disposition of fullerene C60 in rats following intratracheal or intravenous administration | journal=Xenobiotica; the Fate of Foreign Compounds in Biological Systems | volume=49 | issue=9 | pages=1078–1085 | doi=10.1080/00498254.2018.1528646 | pmid=30257131}}</ref>

=== Oils with C60 and risks ===
An experiment in 2011–2012 administered a solution of {{chem|C|60}} in olive oil to rats, achieving a 90% prolongation of their lifespan.<ref name="Baati-2012" /> {{chem|C|60}} in olive oil administered to mice resulted in no extension in lifespan.<ref>{{cite journal | vauthors=Grohn KJ, Moyer BS, Moody KJ | title=C60 in olive oil causes light-dependent toxicity and does not extend lifespan in mice | journal=[[GeroScience]] | volume=49 | issue=2 | pages=579–591 | year=2021 |  doi = 10.1007/s11357-020-00292-z | pmc=8110650 | pmid=33123847 | doi-access=free }}</ref> {{chem|C|60}} in olive oil administered to [[Beagle|beagle dogs]] resulted in a large reduction of [[C-reactive protein]], which is commonly elevated in [[cardiovascular disease]] and [[cerebrovascular disease]].<ref>{{cite journal | vauthors=Hui M, Jia X, Shi M | title=Anti-Inflammatory and Antioxidant Effects of Liposoluble C60 at the Cellular, Molecular, and Whole-Animal Levels| journal=[[Journal of Inflammation Research]] | volume=16 |  pages=83–89 | year=2023 |  doi = 10.2147/JIR.S386381 | pmc=8110650 | pmid=36643955 | doi-access=free }}</ref> 

Many oils with {{chem|C|60}} have been sold as antioxidant products, but it does not avoid the problem of their sensitivity to light, that can turn them toxic. A later research confirmed that exposure to light degrades solutions of {{chem|C|60}} in oil, making it toxic and leading to a "massive" increase of the risk of developing cancer (tumors) after its consumption.<ref name="Grohn, Kristopher J.-2021" /><ref name="Grohn-2021">{{Cite web|last=Grohn |first=Kristopher J. |display-authors=etal |title=C60 in olive oil causes light-dependent toxicity|url-status=live |url=https://gwern.net/docs/longevity/2020-grohn.pdf|access-date=2021-04-15|archive-date=2021-04-15|archive-url=https://web.archive.org/web/20210415212442/https://www.gwern.net/docs/longevity/2020-grohn.pdf}}</ref>

To avoid the degradation by effect of light, {{chem|C|60}} oils must be made in very dark environments, encased into bottles of great opacity, and kept in darkness, consumed under low light conditions and accompanied by labels to warn about the dangers of light for {{chem|C|60}}.<ref name="Grohn-2021"/><ref name="Taylor-1991">{{Cite magazine|magazine=Nature|title=Degradation of C60 by light|date=23 May 1991|volume=351 |url=https://nature.com/articles/351277a0.pdf|author-first1=Roger|author-first2=Jonathan P. |author-first3=Anthony G. |author-first4=Steven P. |author-first5=T. John|author-first6=Jonathan P. |author-first7=Harold W. |author-first8=David R. M. |author-last1=Taylor|author-last2=Parsons|author-last3=Avent|author-last4=Rannard|author-last5=Dennis|author-last6=Hare|author-last7=Kroto|author-last8=Walton}}</ref>

Some producers have been able to dissolve {{chem|C|60}} in water to avoid possible problems with oils, but that would not protect {{chem|C|60}} from light, so the same cautions are needed.<ref name="Taylor-1991" />

==References==
{{Reflist|refs=
<ref name="buckminsterfullerene3">{{cite web | title=Buckminsterfullerene: Molecule of the Month | website=chm.bris.ac.uk | date=Jan 1997 | url=http://www.chm.bris.ac.uk/motm/buckyball/c60a.htm | archive-url=https://web.archive.org/web/20210227040433/http://www.chm.bris.ac.uk/motm/buckyball/c60a.htm | archive-date=2021-02-27 | url-status=dead }}</ref>
}}

==Bibliography==
*{{cite book|title=Nanostructured materials for solar energy conversion|editor-last=Sōga |editor-first=Tetsuo |chapter=Fullerene Thin Films as Photovoltaic Material| last=Katz | first=E.A.|year=2006 |isbn=978-0-444-52844-5|publisher=Elsevier|pages= 361–443|chapter-url=https://books.google.com/books?id=GmQR1tuk5IgC&pg=PA361}}

==Further reading==
*{{cite journal|last=Kroto|first=H. W.|author2=Heath, J. R. |author3=O'Brien, S. C. |author4=Curl, R. F. |author5= Smalley, R. E. |title=C<sub>60</sub>: Buckminsterfullerene|journal=Nature|date=November 1985|volume=318|issue=14|doi=10.1038/318162a0|pages=162–163|bibcode = 1985Natur.318..162K |s2cid=4314237}} – describing the original discovery of C<sub>60</sub>
*{{cite journal|last=Hebgen|first=Peter|author2=Goel, Anish |author3=Howard, Jack B. |author4=Rainey, Lenore C. |author5= Vander Sande, John B. |title=Fullerenes and Nanostructures in Diffusion Flames|journal=Proceedings of the Combustion Institute|year=2000|volume=28|pages=1397–1404|url=http://web.mit.edu/anish/www/Peter-JBH.pdf|doi=10.1016/S0082-0784(00)80355-0|citeseerx=10.1.1.574.8368}} – report describing the synthesis of {{chem|C|60}} with combustion research published in 2000 at the 28th International Symposium on Combustion

==External links==
{{Sister project links|wikt=buckminsterfullerene|commons=Category:Fullerenes|n=no|q=no|s=no}}
*[http://www.chm.bris.ac.uk/motm/buckyball/c60a.htm History of C<sub>60</sub>'s discovery carried out by the Chemistry Department at Bristol University]
*[https://web.archive.org/web/20151023071900/http://scifun.chem.wisc.edu/chemweek/buckball/buckball.html A brief overview of buckminsterfullerene described by the University of Wisconsin-Madison]
*[https://archive.today/20121218095142/http://cccmkc.edu.hk/~sbj-chemistry/98-99%20S.6%20Project/Buckminsterfullerene/Properties%20of%20Buckminsterfullerene.htm A report by Ming Kai College detailing the properties of buckminsterfullerene]
*[http://www.nature.com/physics/looking-back/kraetschmer/index.html Donald R. Huffman and Wolfgang Krätschmer's paper pertaining to the synthesis of {{chem|C|60}} in ''Nature'' published in 1990]
*[https://web.archive.org/web/20130702064627/http://www.ornl.gov/info/ornlreview/rev26-2/text/rndmain1.html A thorough description of {{chem|C|60}} by the Oak Ridge National Laboratory]
*[http://cnx.org/content/m14355/latest/ An article about buckminsterfullerene on Connexions Science Encyclopaedia]
*[http://www.creative-science.org.uk/propc60.html Extensive statistical data compiled by the University of Sussex on the numerical quantitative properties of buckminsterfullerene]
*[http://www.eskimo.force9.co.uk/fullerene/ A web portal dedicated to buckminsterfullerene, authored and supported by the University of Bristol]
*[http://www.chm.bris.ac.uk/webprojects2002/knowles/ Another web portal dedicated to buckminsterfullerene, authored and supported by the Chemistry Department at the University of Bristol]
*[http://www.azonano.com/article.aspx?ArticleID=1641 A brief article entirely devoted to {{chem|C|60}} and its discovery, structure, production, properties, and applications]
*[https://web.archive.org/web/20121029023510/http://portal.acs.org/portal/acs/corg/content?_nfpb=true American Chemical Society's complete article on buckminsterfullerene]
*[http://www.periodicvideos.com/videos/mv_buckyball.htm Buckminsterfullerene] at ''[[The Periodic Table of Videos]]'' (University of Nottingham)

{{Allotropes of carbon}}
{{Molecules detected in outer space}}
{{Buckminster Fuller}}
{{Authority control}}

[[Category:Fullerenes]]