Solubility of fullerenes

60 in solution C
60 in extra virgin olive oil showing the characteristic purple color of pristine C
60 solutions

The solubility of fullerenes is generally low. Carbon disulfide dissolves 8g/L of C60, and the best solvent (1-chloronaphthalene) dissolves 53 g/L. up Still, fullerenes are the only known allotrope of carbon that can be dissolved in common solvents at room temperature. Besides those two, good solvents for fullerenes include 1,2-dichlorobenzene, toluene, p-xylene, and 1,2,3-tribromopropane. Fullerenes are highly insoluble in water, and practically insoluble in methanol.

Solutions of pure C60 (buckminsterfullerene) have a deep purple color. Solutions of C70 are reddish brown. Larger fullerenes C
76 to C
84 have a variety of colors. C
76 has two optical forms, while other larger fullerenes have several structural isomers.

## General considerations[edit]

Some fullerene structures are not soluble because they have a small band gap between the ground and excited states. These include the small fullerenes C
28,[1] C
36 and C
50. The C
72 structure is also in this class, but the endohedral version with a trapped lanthanide-group atom is soluble due to the interaction of the metal atom and the electronic states of the fullerene. Researchers had originally been puzzled by C
72 being absent in fullerene plasma-generated soot extract, but found in endohedral samples. Small band gap fullerenes are highly reactive and bind to other fullerenes or to soot particles.

Solubility of C
60 in some solvents shows unusual behaviour due to existence of solvate phases (analogues of crystallohydrates). For example, solubility of C
60 in benzene solution shows maximum at about 313 K. Crystallization from benzene solution at temperatures below maximum results in formation of triclinic solid solvate with four benzene molecules C
60·4C
6H6 which is rather unstable in air. Out of solution, this structure decomposes into usual face-centered cubic (fcc) C
60 in few minutes' time. At temperatures above solubility maximum the solvate is not stable even when immersed in saturated solution and melts with formation of fcc C
60. Crystallization at temperatures above the solubility maximum results in formation of pure fcc C
60. Millimeter-sized crystals of C
60 and C
70 can be grown from solution both for solvates and for pure fullerenes.[2][3]

## Solubility table[edit]

The following are some solubility values for C
60 and C
70 from the literature, in grams per liter.[4][5][6][7][8]

Solvent  | C
60 | C

|
|

1-chloronaphthalene | 51 | ND
1-methylnaphthalene | 33 | ND
1,2-dichlorobenzene | 24 | 36.2
1,2,4-trimethylbenzene | 18 | ND
tetrahydronaphthalene | 16 | ND
carbon disulfide | 8 | 9.875
1,2,3-tribromopropane | 8 | ND
chlorobenzene | 7 | ND
p-xylene | 5 | 3.985
bromoform | 5 | ND
cumene | 4 | ND
toluene | 3 | 1.406
benzene | 1.5 | 1.3
carbon tetrachloride | 0.447 | 0.121
chloroform | 0.25 | ND
n-hexane | 0.046 | 0.013
cyclohexane | 0.035 | 0.08
tetrahydrofuran | 0.006 | ND
acetonitrile | 0.004 | ND
methanol | 4.0×10−5 | ND
water | 1.3×10−11 | ND
pentane | 0.004 | 0.002
heptane | ND | 0.047
octane | 0.025 | 0.042
isooctane | 0.026 | ND
decane | 0.070 | 0.053
dodecane | 0.091 | 0.098
tetradecane | 0.126 | ND
acetone | ND | 0.0019
isopropanol | ND | 0.0021
dioxane | 0.0041 | ND
mesitylene | 0.997 | 1.472
dichloromethane | 0.254 | 0.080
ND = not determined

## See also[edit]

* Fullerene chemistry

## References[edit]

1. ^ Guo, T.; Smalley, R.E.; Scuseria, G.E. (1993). "Ab initio theoretical predictions of C
28, C
28H4, C
28F4, (Ti@C
28)H4, and M@C
28 (M = Mg, Al, Si, S, Ca, Sc, Ti, Ge, Zr, and Sn)". Journal of Chemical Physics. 99 (1): 352. Bibcode:1993JChPh..99..352G. doi:10.1063/1.465758.C28,+C28H4,+C28F4,+(Ti@C28)H4,+and+M@C28+(M+=+Mg,+Al,+Si,+S,+Ca,+Sc,+Ti,+Ge,+Zr,+and+Sn)&rft.volume=99&rft.issue=1&rft.pages=352&rft.date=1993&rft_id=info:doi/10.1063/1.465758&rft_id=info:bibcode/1993JChPh..99..352G&rft.aulast=Guo&rft.aufirst=T.&rft.au=Smalley,+R.E.&rft.au=Scuseria,+G.E.&rfr_id=info:sid/en.wikipedia.org:Solubility+of+fullerenes" class="Z3988">
2. ^ Talyzin, A.V. (1997). "Phase Transition C
60−C
60*4C
6H6 in Liquid Benzene". Journal of Physical Chemistry B. 101 (47): 9679–9681. doi:10.1021/jp9720303.C60−C60*4C6H6+in+Liquid+Benzene&rft.volume=101&rft.issue=47&rft.pages=9679-9681&rft.date=1997&rft_id=info:doi/10.1021/jp9720303&rft.aulast=Talyzin&rft.aufirst=A.V.&rfr_id=info:sid/en.wikipedia.org:Solubility+of+fullerenes" class="Z3988">
3. ^ Talyzin, A.V.; Engström, I. (1998). "C
70 in Benzene, Hexane, and Toluene Solutions". Journal of Physical Chemistry B. 102 (34): 6477–6481. doi:10.1021/jp9815255.C70+in+Benzene,+Hexane,+and+Toluene+Solutions&rft.volume=102&rft.issue=34&rft.pages=6477-6481&rft.date=1998&rft_id=info:doi/10.1021/jp9815255&rft.aulast=Talyzin&rft.aufirst=A.V.&rft.au=Engström,+I.&rfr_id=info:sid/en.wikipedia.org:Solubility+of+fullerenes" class="Z3988">
4. ^ Beck, Mihály T.; Mándi, Géza (1997). "Solubility of C
60". Fullerenes, Nanotubes and Carbon Nanostructures. 5 (2): 291–310. doi:10.1080/15363839708011993.C60&rft.volume=5&rft.issue=2&rft.pages=291-310&rft.date=1997&rft_id=info:doi/10.1080/15363839708011993&rft.aulast=Beck&rft.aufirst=Mihály+T.&rft.au=Mándi,+Géza&rfr_id=info:sid/en.wikipedia.org:Solubility+of+fullerenes" class="Z3988">
5. ^ Bezmel'nitsyn, V.N.; Eletskii, A.V.; Okun', M.V. (1998). "Fullerenes in solutions". Physics-Uspekhi. 41 (11): 1091–1114. Bibcode:1998PhyU...41.1091B. doi:10.1070/PU1998v041n11ABEH000502.
6. ^ Ruoff, R.S.; Tse, Doris S.; Malhotra, Ripudaman; Lorents, Donald C. (1993). "Solubility of fullerene (C
60) in a variety of solvents" (PDF). Journal of Physical Chemistry. 97 (13): 3379–3383. doi:10.1021/j100115a049.C60)+in+a+variety+of+solvents&rft.volume=97&rft.issue=13&rft.pages=3379-3383&rft.date=1993&rft_id=info:doi/10.1021/j100115a049&rft.aulast=Ruoff&rft.aufirst=R.S.&rft.au=Tse,+Doris+S.&rft.au=Malhotra,+Ripudaman&rft.au=Lorents,+Donald+C.&rft_id=http://bucky-central.me.utexas.edu/RuoffsPDFs/40.pdf&rfr_id=info:sid/en.wikipedia.org:Solubility+of+fullerenes" class="Z3988">
7. ^ Sivaraman, N.; Dhamodaran, R.; Kaliappan, I.; Srinivasan, T. G.; Vasudeva Rao, P. R. P.; Mathews, C. K. C. (1994). "Solubility of C
70 in Organic Solvents". Fullerene Science and Technology. 2 (3): 233–246. doi:10.1080/15363839408009549.C70+in+Organic+Solvents&rft.volume=2&rft.issue=3&rft.pages=233-246&rft.date=1994&rft_id=info:doi/10.1080/15363839408009549&rft.aulast=Sivaraman&rft.aufirst=N.&rft.au=Dhamodaran,+R.&rft.au=Kaliappan,+I.&rft.au=Srinivasan,+T.+G.&rft.au=Vasudeva+Rao,+P.+R.+P.&rft.au=Mathews,+C.+K.+C.&rfr_id=info:sid/en.wikipedia.org:Solubility+of+fullerenes" class="Z3988">
8. ^ Semenov, K. N.; Charykov, N. A.; Keskinov, V. A.; Piartman, A. K.; Blokhin, A. A.; Kopyrin, A. A. (2010). "Solubility of Light Fullerenes in Organic Solvents". Journal of Chemical & Engineering Data. 55: 13–36. doi:10.1021/je900296s.