Talk:Charge-transfer complex
 | This article is rated C-class on Wikipedia's content assessment scale. It is of interest to the following WikiProjects: | ||||||||||
| |||||||||||
Chemistry, Language, etc
[edit]This was written by someone who thinks that trinitrobenzene is an "electron-deficient molecule". The number of negative charges in this molecule is exactly equal to the number of positive charges - i.e. it is a neutral molecule. However, it is "electro-negative", in the same way that a neutral chlorine atom is electronegative. Maybe written by a non-chemist? But, OK, I know - expertise in the subject at hand is frowned upon in Wikipedia.
Historic
[edit]Meh. Charge transfer is a more general term than I realized...I need to think more, but I think I'll end up writing an article called charge transfer and redirecting this article. Just thought I'd leave up this stub for anyone else to contribute, as it is an important term.
TCNQ's structure is wrong - are those carbons pentavalent? ;)
well spotted, the image will have to be modified V8rik 17:51, 24 January 2006 (UTC)
- just came here to note the same observation Xcomradex 04:26, 28 August 2006 (UTC)
FIgure 1 is not there? 122.59.234.8 (talk) 23:20, 24 August 2011 (UTC)
Most of this article seems to be off-topic
[edit]At least to my reading, the section Charge-transfer complex#Inorganic charge-transfer complexes and Charge-transfer complex#Charge-transfer transition energy are off-topic. Charge-transfer electronic transitions are distinct topic and kinda unrelated to a real CT complex. CT complexes are donor-acceptor salts, usually. Things like Bechgaard salt and TTF-TCNQ. So before I did something dramatic (or stupid) - like chopping that part out - please voice your comments and suggestions. --Smokefoot (talk) 15:03, 24 February 2013 (UTC)
- Yes, I agree that this article now confuses two topics. Rather than chopping the spectroscopic content out of Wikipedia, it should be moved to a new article. If the two topics were in separate articles, readers would be less likely to confuse the two.
- The first topic is complexes formed by charge transfer in the ground state, so that the complexes can be isolated, which is what I think Smokefoot means by calling them real. These could be called charge-transfer complexes but I think a better article title would be something like Electron donor-acceptor complexes, to include both salts and simple Lewis acid-base complexes.
- The second topic is charge transfer in excited states observed in absorption spectra, and the second article could be called charge-transfer electronic transitions. Dirac66 (talk) 15:01, 28 February 2013 (UTC)
- I strongly disagree. CT bands are the single most characteristic property of these complexes, directly related to the bonding nature of the complexes. The mentioning that CT complexes are mostly salts, is completely wrong, in fact more of them are probably not salts, but the kind of organic and biological complexes of the weak kind. The article should indeed discuss both the chemical structure and nature, as well as the electronic and optical properties that are so characteristic of these complexes. Without these characteristics, they would never have found special interest, or be given the separate classification from salts. I restored the content�. Kbrose (talk) 00:10, 31 May 2013 (UTC)
- Often the relationship between CT bands and CT salts are confused. I see this confusion often in the classroom. User:Dirac66 and I were trying to separate these two concepts. Specifically, some CT salts have CT bands but most compounds exhibiting CT bands are not CT salts. If one thinks of some of the most famous CT salts, TTF-TCNQ, there is no real interest in their optical properties. The interest was in their electrical properties. Similarly, the CT complex that precedes aromatic nitration involving NO2 and the arene pi-radical cation are not of interest for their optical properties, but in terms of their intermediacy in an important chemical reaction. In any case, I welcome your views and learning from each other. --Smokefoot (talk) 02:02, 3 June 2013 (UTC)
- After checking several inorganic chemistry textbooks, I agree that CT complexes and CT bands are closely related and can be in one article. The point is that in a CT complex, the same attractive interaction which forms the donor-acceptor bonding orbital often also forms a high-energy antibonding orbital and excited state for the CT spectral transition(s). So all right, let’s keep the two topics (or two aspects) together, and work on clarifying the relationship between the different parts of the subject.
- Also, different sources disagree on which molecules are described as charge-transfer. Some authors would include only weak complexes such as iodine with an organic donor. However spectral bands of transition metal complexes are widely described as LMCT and MLCT, and many who work with organic salts such as TTF-TCNQ also describe them as (strong) charge-transfer complexes. So Wikipedia should remain neutral and include the various uses of the term, although we can mention that not every one agrees. Dirac66 (talk) 16:15, 4 June 2013 (UTC)
- One solution might be to create an article on MLCT/LMCT since that is the crux of my concern. --Smokefoot (talk) 18:00, 4 June 2013 (UTC)
- For MLCT/LMCT bands we should first decide between two interpretations: (1) TM complexes are NOT CT complexes, in which case MLCT/LMCT bands are a phenomenon related to CT bands in another class of molelcules, in which case I think yes, they should be in a separate article, or (2) TM complexes are essentially strong CT complexes, in which case MLCT/LMCT bands belong in this article. Perhaps I will leave you to think about this point and consult Kbrose.
- In the meantime I plan to revise the too-frequent wording (especially in the intro) which suggests that CT transitions (bands) are identical to CT complexes, and specify instead that CT transitions are a property of many CT complexes. Dirac66 (talk) 22:16, 4 June 2013 (UTC)
- One solution might be to create an article on MLCT/LMCT since that is the crux of my concern. --Smokefoot (talk) 18:00, 4 June 2013 (UTC)
- Often the relationship between CT bands and CT salts are confused. I see this confusion often in the classroom. User:Dirac66 and I were trying to separate these two concepts. Specifically, some CT salts have CT bands but most compounds exhibiting CT bands are not CT salts. If one thinks of some of the most famous CT salts, TTF-TCNQ, there is no real interest in their optical properties. The interest was in their electrical properties. Similarly, the CT complex that precedes aromatic nitration involving NO2 and the arene pi-radical cation are not of interest for their optical properties, but in terms of their intermediacy in an important chemical reaction. In any case, I welcome your views and learning from each other. --Smokefoot (talk) 02:02, 3 June 2013 (UTC)
- I strongly disagree. CT bands are the single most characteristic property of these complexes, directly related to the bonding nature of the complexes. The mentioning that CT complexes are mostly salts, is completely wrong, in fact more of them are probably not salts, but the kind of organic and biological complexes of the weak kind. The article should indeed discuss both the chemical structure and nature, as well as the electronic and optical properties that are so characteristic of these complexes. Without these characteristics, they would never have found special interest, or be given the separate classification from salts. I restored the content�. Kbrose (talk) 00:10, 31 May 2013 (UTC)
Figure removed
[edit]
This figure has almost nothing to do with CT. The PPh3 is oxidized to give [IPPhh3+]I-, which is not a CT salt. Its just a salt.--Smokefoot (talk) 15:11, 24 December 2020 (UTC)
References
- ^ Housecroft, C. E.; Sharpe, A. G. (2008). Inorganic Chemistry (3rd ed.). Prentice Hall. p. 541. ISBN 978-0-13-175553-6.
Tautology
[edit]A supramolecular assembly contains two or more molecules by definition so to describe it as a supramolecular assembly of two or more molecules is redundant. It would be best to avoid the term to minimise confusing a non expert reader with chemical jargon and just describe it as an assembly of two or more molecules. 217.45.110.113 (talk) 19:19, 4 October 2022 (UTC)