Talk:Fullerene/Archive 2

Toxicity questions

Hi,

I just wanted to comment on the "Possible Dangers" section. It is unfortunate that the only mention of toxicity data is the recent work of Oeberdorster and Colvin. The articles they have published are largely considered irrelevant and misleading by fullerene scientists. They are problematic for several reasons, including:

The assertion that C₆₀ forms "Nano-C₆₀" spontaneously in water is false. The procedure to make a water/C₆₀ colloidal solution such as used in the Colvin studies has been known for years, and requires several solvent replacements and precipitation, and typically would take about a week to carry out. C₆₀ is absolutely insoluble in water, and if placed in water, does nothing more than what ordinary soot or carbon black would do, which is settle or float as a solid.

The "Nano-C₆₀" process used by Colvin et al uses tetrahydrafuran (THF). Russian scientists (experienced with making the colloid for years, and in fact measuring no toxicity on the colloid) have written that THF can, present as solvent inclusions in the C₆₀ precipitate, cause exactly the same toxicity results reported by Colvin and co-workers.

C₆₀ and C₆₀ derivatives have been widely studied for 10 years or more before Colvin and co-workers began their work. In fact, the only real negative toxicity result was reported by Tour around 1996 on the same colloid that Colvin studied. Many fullerene derivatives have been studied for toxicity, including one that Colvin studied. C3, a C₆₀ derivative invented by Wilson and co-workers has been studied since the mid 90's, in vitro and in rats with no adverse toxicity. In fact, this molecule was licensed by Merck & Co. in 2003 for pre-clinical trials in Parkinson's disease.

In the 15 years of researchers using C₆₀ and C₆₀ derivatives, there are no reported anecodotal evidence of any adverse health effects.

It is unfortunate that Colvin et al have not respected the work of literally thousands of researchers, do not cite key review articles on pharmaceutical use such as Da Ros & Prato, Wilson, and others, and mislead the general public on the real science of fullerenes. In fact, the very same molecules that Colvin uses to take credit for having discovered that derivatization can make C₆₀ "safe" were shown to have no toxicity years ago. And, to compare a 50 nm particle (the nano-C₆₀) with a soluble C₆₀ derivative is comparing apples and oranges. In fact, Oberdorster's father has work showing that particles in that size range show toxicity regardless of the chemical makeup.

The radicals that are mentioned in the Wikipedia article are a garbled explanation of the singlet oxygen generation through light absorption by C60. This has also been known for years, and this has not shown to make fullerenes toxic.

For those of you who have written this, and read it, it could be interesting for you to know that in fact one of the most promising uses of fullerenes is as drugs, and at present, both major companies and respected resarch labs around the workd are now pursuing fullerenes for this use. One of the most promising aspects being the almost total absence of adverse toxicity results.

In short, the work that is mentioned in this Wikipedia article is not respected by real chemists, pharmaceutical chemists, and fullerene scientists. Colvin is a professor of nanotechnology, and is trained neither in chemistry or toxicology. Though not having been successful in impressing her fellow scientists with her work, she has been very successful at trying to gather publicity around the "nano-toxicity" scare, which is allowing her to gain a small degree of fame, and more importantly for her, resarch dollars.

As a fullerene scientist with roots going back to their discovery, I would suggest that the section of "Possible Dangers" be deleted until someone versed in the real scientific literature could address the subject in a more serious and considered manner. As it stands, it is scientifically reckless and irresponsible. Wikipedia has recently been in the National news because of other irresponsible use, and if this is not modified, I will address the situation to those responsible at Wikipedia, since misinformation of this sort is damaging to the truth, and disregards the work of thousands of good scientists.

I have removed some unsourced and other ultra-POV comments in the article that implied it wat proven that C₆₀ is toxic. Polonium 21:17, 1 March 2006 (UTC)

Below is a link to Eva Oberdörster's paper, should anyone wish to investigate this matter. The full paper is available free of charge.

• Oberdörster, Eva (2004). Manufactured Nanomaterials (Fullerenes, C₆₀) Induce Oxidative Stress in the Brain of Juvenile Largemouth Bass. Environ Health Perspect 112 (10), 1058-1062.
• Corresponding PubMed listing: PMID:15238277

—Ryanrs 04:33, 17 March 2006 (UTC)

I don't know that either of these studies quoted in this section particularly belong in a discussion of safety: the impact on human or other life at current or even anticipated environmental levels still appears to be negligible. Moreover, what is defined as a "health risk" or "environmental risk" could become something beneficial: for example, being an agent that binds ssDNA, perhaps fullerenes will make good chemotherapy candidates. I am in complete agreement with the first person to comment on this particular section that the inclusion of this information remains controversial in the scientific community, and this section is unreliable as currently written.Tomteboda 02:25, 3 October 2006 (UTC)

Merge from popular culture

There is no good reason for a short orphan article on Fullerenes in popular culture to exist. It would hardly overwhelm this page to add it. Rmhermen 17:26, 2 February 2006 (UTC)

• I agree. —Keenan Pepper 22:21, 2 February 2006 (UTC)
• Yep, merge 'em. Shadow demon 05:26, 17 February 2006 (UTC)

Possible Dangers: "our compounds"

On 15 December 2005, User:216.217.201.187 (contrib) added text that reads, in part:

indicates that our compounds are likely to have little (if any) toxicity (diff)

The phrase our compounds is highly suspicious. It suggests either copyright violation, or worse, subtle spam/astroturfing. —Ryanrs 05:18, 17 March 2006 (UTC)

The phrase "recently discovered" could be replaced with the date the buckyballs were discovered. "Recently" really doesn't tell us anything, even though I;m sure it made sense to the author when it was originally written--24.15.4.45 06:27, 4 April 2006 (UTC)

Merge from Buckminster Fullerene

Merge. These are exactly the same subject. On the other hand, articles on individual fullerene molecules, such as (C₆₀-I_h)[5,6]fullerene (the most common one) might be a good idea. —Keenan Pepper 10:59, 13 April 2006 (UTC)

• Slight agree - They are not the same thing: buckminsterfullerene is to the fullerenes as methane is to the alkanes; it is simply a single member of a family group. However, having said that, I do still think they should be merged as it will be a while till buckyballs are risen to the profile of methane. At this current point in time, having two seperate articles is a touch trivial. mastodon 21:09, 14 April 2006 (UTC)

Did you read the article Buckminster Fullerene? It's not about any specific molecule. If it were, I would suggest it be moved to the IUPAC name, for example (C60-Ih)(5,6)fullerene ((C₆₀-I_h)[5,6]fullerene formatted as an article title). —Keenan Pepper 02:47, 15 April 2006 (UTC)

I see your point, I had not read it. Having now read it I change my answer to a full agree. Could you explain the systematic name please? Although most molecules have a systematic name, the historic name is often prefered, eg. methyl benzene vs toluene. I think that buckyball will prevail as its official name as it is by far the easiest to pronounce, so maybe the article should be moved to that? I've reformatted fullerene, what do you think? mastodon 03:18, 15 April 2006 (UTC)

See http://www.chem.qmul.ac.uk/iupac/fullerene/ for the details. Fullerene and buckyball are both general names for this class of compounds. The trivial name of (C₆₀-I_h)[5,6]fullerene is [60-I_h]fullerene and the trivial name of (C₇₉-D_5h(6))[5,6]fullerene is [70-D_5h]fullerene. —Keenan Pepper 05:21, 15 April 2006 (UTC)

• Strongly agree - They are basically describing the same thing. We never, or almost never, keep two different Wikipedia articles on the same thing from the same perspective (chemical, political, medical, etc.) -User:Nightvid

I'll go ahead and merge them then, since there are no objections. —Keenan Pepper 02:12, 16 April 2006 (UTC)

Category Chemical Elements

Why is this article listed in the category "Chemical Elements"? Fullerenes are molecules, as the article says. -- 85.180.152.67 17:56, 18 July 2006 (UTC)

But they are elemental molecules, as they contain only carbon atoms.128.6.30.196 22:28, 7 November 2006 (UTC)

References #2 and #3 are dead links

3: The link is dead and the directing website seems to only keep articles in that catergory ("Nano Debate") for the present year.Lizz612 01:16, 27 July 2006 (UTC)

2: The reference for the buckyball being Texas' state molecule is dead, and I could not trace it down on the new website. --Sailor Coruscant 02:48, 12 October 2006 (UTC)

Maximum Length of Carbon Nanotubes

The main article on Carbon Nanotubes says they can be up to a few mm long; this article says they can be a full meter. Could somebody who knows which is right please correct the other? —The preceding unsigned comment was added by 72.61.73.16 (talk • contribs) .

I can't find anyone who claims to have made meter-long nanotubes, although I can find a lot of things that could be misinterpreted as saying that. I'll change it to agree with Carbon nanotube for now. —Keenan Pepper 02:18, 6 August 2006 (UTC)

non-planar? what gives?!

From what I gather the fullerenes can be embedded in either a sphere or a cylinder. This makes them embeddable in the plane. And certainly neither a cycle of 5 nor of 7 prevent a planar embedding. I'd be inclined to change this, but will wait to be corrected, please. MotherFunctor 21:58, 30 August 2006 (UTC)

This is confused by the fact that later in the article, it describes "the term fullerene refers to any 3-regular, planar graph with all faces of size 5 or 6 (including the external face)". Seanahan 04:26 19 October 2006 (UTC)

Buckyeggs

Fresh from Slashdot:

Improbable "Buckyegg" Hatched

A buckyegg breaks pentagon rules

Abstract of: "Tb3N@C84: An Improbable, Egg-Shaped Endohedral Fullerene that Violates the Isolated Pentagon Rule" (Volume 128, Issue, Pages 11352-11353, September 6, 2006)

Basically, an egg-shaped fullerene which contains touching pentagon formations. Cites above for anyone interested (and inclined) in fullerene chemestry or nanomaterials. ~Kylu (u|t) 21:35, 30 September 2006 (UTC)

Comment on the Potential of C-60 as an Inhibitor to the HIV Virus ?

This seems worthy of mention; apparently the buckyball are bigger than charlies balls and can interfere with a crucial protease that the virus uses to reproduce.

http://www.chem.wisc.edu/~newtrad/CurrRef/BDGTopic/BDGtext/bmmbas.html

Infinitys 7th 20:22, 27 November 2006 (UTC)

R.W. Henson

Is there any place for an acknowledgement of his contribution in this article? R.W. Henson's website DavidFarmbrough 10:36, 8 December 2006 (UTC)

Buckyball and soccerball

In the first paragraph, it says that C₆₀ molecules are sometimes called "buckyballs" because they look like a soccerball. However, it is called that because Buckminster Fuller, an architect, created geodesic domes resembling C-60. It may be called a ball because it is, but the "bucky-" part has nothing to do with it. Should not this sentence be reworded/removed? —The preceding unsigned comment was added by 204.152.152.23 (talk) 18:53, 2 March 2007 (UTC).

3D structure of nano-Bytes —Preceding unsigned comment added by 24.74.114.191 (talk) 18:46, 9 March 2008 (UTC)

Because C₆₀ has two different bond lengths, is it really shaped like a truncated icosahedron, which has all edges the same length? Grassynoel (talk) 16:43, 4 August 2008 (UTC)

Shungites

"Recently, Buckminsterfullerenes were found in a family of minerals known as Shungites in Karelia, Russia." Is the statement wrong. Can someone read the paper (do not have access) http://geology.geoscienceworld.org/cgi/content/abstract/31/3/255 and reply http://geology.geoscienceworld.org/cgi/content/extract/31/6/e33 As I understood the first article is incorrect. Can you, please, clarify it. Alexander Mayorov (talk) 19:36, 18 March 2008 (UTC)

The Safety section is poorly written and could be biased and inaccurate: be prudent

Moussa et al. (1996, 1997) studied the in vivo toxicity of C₆₀ after intra-peritoneal administration of large doses. No evidence of toxicity was found and the mice tolerated a dose of 5000 mg/kg of body weight (BW). Mori et al. (2006) confirmed the absence of toxicity in rodents for C₆₀ and C₇₀ mixtures after oral administration of a dose of 2000 mg/kg BW and showed no evidence of genotoxic or mutagenic potential in vitro. Recently, many studies have shown fullerenes to be non-toxic, on the contrary, Gharbi et al. (2005) showed that aqueous C₆₀ suspensions not only have no acute or subacute toxicity in rodents but they also protect their livers in a dose-dependent manner against free-radical damage. A comprehensive and recent review on fullerene toxicity is given by Kolosnjaj et al. (2007). These authors review the works on fullerene toxicity beginning in the early 1990's to present, and conclude that the evidence gathered since the discovery of fullerenes overwhelmingly suggests that C₆₀ is non-toxic.

References on Safety

The references were not properly inserted in this section on safety: it should be advised to clearly separate in-text citations and full references to be included in the references list at the end of the article. Moreover, the list of all authors should be given in the references list. This section only put forward the absence of toxicity of fullerene and could be systematically biased by a lack of criticism. I would suggest to be more critic and more prudent. The inadequate format of the citations and references in this section could reveal the inexperience of the contributor who added them. What about inhalation of fullerene in the lungs ? A priori, one could expect the same kind of problems than with nanoparticles ! This section should be thoroughly reviewed by a specialist in toxicology.

To help, I have started to extract the references out of the existing text and compiled a temporary list to be checked and completed for all the author names.

• Moussa F. et al. (1996) Fullerene Sci. Technol. 4, pp. 21-29.
• Moussa F. et al. (1997) Proc. Electrochem. Soc. 5, pp. 332-336.
• Mori T. et al. (2006) Toxicology 225, pp. 48–54.
• Gharbi N. et al. (2005) Nano Letters vol.5, No. 12, pp. 2578-2585.
• Kolosnjaj J. et al. (2007) Toxicity studies of fullerenes and derivatives. In: Bioapplications of nanoparticles. Eds WC Chan, Landes Biosciences, Toronto, On, CA. 2007, Chap 13, pp.168-180.

Shinkolobwe (talk) 18:55, 13 June 2008 (UTC)

Attention ! Carbon nanotubes can show asbestos-like pathogenicity

By the way, today, I just found a paper providing evidences of the opposite thesis: carbon nanotubes can show asbestos-like pathogenicity ! One more reason to be prudent in this section.

• Poland, C. A., Duffin, R., Kinloch, I., Maynard, A., Wallace, W. A. H., Seaton, A., et al. (2008) Carbon nanotubes introduced into the abdominal cavity of mice show asbestos-like pathogenicity in a pilot study. Nat Nano, advanced online publication. doi:10.1038/nnano.2008.111.

Shinkolobwe (talk) 12:21, 16 June 2008 (UTC)

Examples of fullerenes in popular culture

While it is true that fullerenes have become popular in segments of society beyond chemistry, this section is not only mostly irrelevant, but also some completely arbitrary trivia. The few useful facts should be merged into the article proper, and the section done away with. dimo414 (talk) 21:03, 19 June 2008 (UTC)

Small bandgap vs. large, or vs. none?

In the Solubility section it says: "Some fullerene structures are not soluble because they have a small band gap between the ground and excited states." I'm interested to understand this, but haven't heard of effects of electronic band-gap on a substance's physical self-cohesion. Might be nice if the author could find a reference to an explanation, but even more fundamental is: what's the other state that this is distinct from? Is it no bandgap at all, or a considerably larger band-gap? jimswen (talk) 21:14, 23 July 2008 (UTC)

Graph of 60 Fullerene

Having looked at the image of 60-Fullerene (see Right), there appears to be a missing node. On the left side of the central pentagon, at the meeting of 2 of the hexagons surrounding it, the lines meet in a triangle, but there is no node. I lack an svg editor, would someone be able to put in the missing node?

--Danny252 (talk) 18:47, 8 September 2008 (UTC)

I've added the missing node. --Itub (talk) 17:27, 14 October 2008 (UTC)

C28 Superconductive in roomtempereture?

Hello,

I read a while a go that C28 fullerene could be solution for room temperature superconductive material. http://www.freepatentsonline.com/70187153.html

Any comments?

217.140.250.192 (talk) 15:17, 13 October 2008 (UTC)Timppa

Polymerized single-walled nanotubes

The following text ...
Polymerized single-walled nanotubes (P-SWNT) are a class of fullerites and are comparable to diamond in terms of hardness. However, due to the way that nanotubes intertwine, P-SWNTs do not have the corresponding crystal lattice that makes it possible to cut diamonds neatly. This same structure results in a less brittle material, as any impact that the structure sustains is spread out throughout the material. Because nanotubes are still very expensive to produce in useful quantities, uses for a material lighter and stronger than steel will have to wait until nanotube production becomes more economically viable.
...was struck out with the comment "There is no reports of polymerised single walled carbon nanotubes. Some efforts have been tried but since the only reactive sites of a carbon nanotube where a polymeric bond could occur is at the caps of the tubes the probability to polymerise for a nanotube is neglible. The only two fullerenes that has been shown to polymerise is C60 and C70, where the already for the C70 the probabliity is strongly reduced. Single walled carbon nanotubes van however be functionalised where the side wall carbons might crosslink to other atoms. This class of material is however that in no way comes close to diamond in hardness. "
I have moved the disputed text and the comment here for discussion. -- Ed (Edgar181) 00:14, 19 September 2009 (UTC)