Talk:Carbene

From Wikipedia, the free encyclopedia

	Chemistry Portal Carbene is within the scope of WikiProject Chemicals, a daughter project of WikiProject Chemistry, which aims to improve Wikipedia's coverage of chemicals. To participate, help improve this article or visit the project page for details on the project.
Article Grading: The article has not been rated for quality and/or importance yet. Please rate the article and then leave comments here to explain the ratings and/or to identify the strengths and weaknesses of the article..

Contents 1 singlet/triplet labels in carbene addition reaction 2 Further research 3 Carbenes, Persistent carbenes, NHC's ?? 4 Reminders to editors

[edit] singlet/triplet labels in carbene addition reaction

Is it me, or are the labels for singlet and triplet reversed in the carbene addition to the alkene reaction? The singlet should be the top, concerted, stereospecific reaction, correct? That's what the text implies... Ed Sanville 07:12, 14 January 2006 (UTC)

I think the top one should be the singlet, at least according to the text. (unsigned comment)

Fixed. DMacks 02:30, 23 February 2006 (UTC)

[edit] Further research

I think 'further research' remarks like:

Further studies are being conducted in order to test the effects of added substituents onto the carbene. These studies are being conducted at the University of California, Irvine School of Physical sciences. <!-- need actual cite here -->

should not be in the original text. Probably more groups are studying these systems. --Dirk Beetstra 08:33, 10 May 2006 (UTC)

Concurred. Actually, that whole sulfinyl carbene can probably be removed, since there's nothing notable mentioned about it. There's no citation other than an institution name, the only reference at uci.edu I can find about it is that an undergrad is working on it this year, and there's no ACS publication by the PI (Freeman) about it. And the IP maps to uci also. Sounds suspiciously like the guy is reporting his own original research. DMacks 15:00, 10 May 2006 (UTC)

Hmmm, I did not read it like that, yet. Indeed, I guess the whole section can be removed. It is 'just another carbene' where some group is currently working on, I will move it here:

Another example of a carbene is methanesulfinyl carbene, molecular formula CHS(O)CH₃, having a hydrogen and a sulfinyl (S(O)CH₃) group bound to the sp² carbon. Using the Density Functional B3LYP method with a 6-31G+(d) basis set, calculations indicate that the triplet state of this molecule is more stable than its singlet counterpart.<!-- references needed here -->

Cheers, Dirk Beetstra 15:53, 10 May 2006 (UTC)

[edit] Carbenes, Persistent carbenes, NHC's ??

I was informed that 'persistent carbenes' (a section in the main article) was a candidate for a seperate article later on (that is, when it was big enough).

Somehow I feel that it might be a good plan to split of a part, but I would then like to suggest to make a seperate article about the N-Heterocyclic Carbenes (and the like). To me the subject/term 'persistent carbene' belongs in this article (because, persistent is a relative measure, for someone studying a compound by NMR, persistent is several minutes, for a laser-spectroscopist, femtoseconds are already long enough). The NHC's, on the other hand, grow into a seperate group of organic molecules (and there are even organometallic analogues, the silylenes and germylenes), with their own chemistry, and they get extensively used nowadays in organometallic chemistry as ligands. I'd like to hear some pro's and con's before starting to move things around.

By the way, I noticed that there is already an article Transition metal carbene complex (I don't know if I would search it there ..). This one might also be taken into consideration in this discussion (I'll make a link from the talk-page of that page). Dirk Beetstra 21:35, 11 May 2006 (UTC)

• The History of stable carbenes is a great addition to this article, two remarks though: the persistent carbenes are ready for a spin-off and an article of their own, like suggested in the discussion above. Also the link density is poor: by linking keywords in the text to other articles the article will improve and also become unstandable for less chemistry-experienced readers V8rik 20:40, 10 August 2006 (UTC)

[edit] Reminders to editors

Please use the Edit summary field to document what changes you are making. A stream of blank-summary changes from an anon-IP is a common sign of vandalism...help your worthwhile changes get the respect they deserve:) Which leads me to my other suggestion: if you're going to be doing a log of Wiki editing, consider creating an account and log in so that edits are associated with a specific editor instead of an IP. Multiple editors could have the same IP and any given editor might use several different IPs. DMacks 16:26, 11 August 2006 (UTC)