Talk:Non-covalent interaction

message: (Copied over from User talk:Itub):
I'm puzzled by your [Sadi Carnot's] removal of the merge tag from non-covalent bonding with the reason "non-covalent bonding is important in the field of supramolecular chemistry according to Lehn". I'm not questioning the importance of non-covalent bonding. What I'm questioning is whether the Wikipedia articles currently titled non-covalent bonding and intermolecular interaction actually deal with different topics. My opinion is that they don't, and therefore having two articles is redundant. I don't have a strong preference regarding the title of the resulting article, though. --Itub 12:33, 12 March 2007 (UTC)
replies: text: While I appreciate your effort to organize, I have interest in supermolecular chemistry and although one could loosely merge these without to much difficulty, I reason that they should remain separate.  Although I need to read more in this area, from what I understand so far Jean-Marie Lehn, the main founder of this field, who won the 1987 Nobel Prize for his work in SMC, defines “molecular chemistry”, as begun by Friedrich Wohler in 1828, as related to the making and breaking of covalent bonds.  He contrasts this with the new field of “supramolecular chemistry” as related to the making and breaking of non-covalent bonds between supermolecules.  Intermolecular forces, on the other had, is a more general term which may include the covalent bond if fashioned so. If you don’t believe me, look at this edit by User:V8rik, in which the intro definition of supramolecular chemistry is defined by the use of the term “noncovalent bonding.  I hope this helps? --Sadi Carnot 00:26, 13 March 2007 (UTC)
replies: text: I'm still not convinced. The terms "noncovalent bonding" and "intermolecular interaction" are used synonymously (yet another synonym is "weak interactions/bond"). A good example is the reference you provide: it says "Supramolecular chemistry is a highly interdisciplinary field of science covering the chemical, physical, and biological features of chemical species of higher complexity, that are held together by means of intermolecular (noncovalent) binding interactions'" (emphasis mine). Intermolecular interactions conventionally never include the covalent bond; (I'd say it's because if you bind two molecules with a covalent bond you end up with one molecule, and the interaction is no longer considered intermolecular. This may seem in contradiction with the fact that the "intermolecular" forces also act intramolecularly, but the convention still is to call these forces "intermolecular" in general. The nature of the force does not depend on whether it is intermolecular or intramolecular.) My conclusion is still the same: the two articles are dealing with the same topic: hydrogen bonding, ionic and dipole interactions, and dispersion forces and should be merged. --Itub 08:50, 13 March 2007 (UTC)

text: Also see Lehn's Nobel lecture , which begins with "Supramolecular chemistry is the chemistry of the intermolecular bond" and frequently alternates between intermolecular and non-covalent. --Itub 09:23, 13 March 2007 (UTC)

text: I’m still not really in favor of a merge.  I’ve found this definition of noncovalent bonds in a standard textbook of molecular cell biology; and a second one in a standard biology textbook.  I’ll add these to the article.  I hope this helps? --Sadi Carnot 07:44, 9 April 2007 (UTC)
replies: text: After reading the link you provided, I still see no difference (and note that the link acknowledges that they are also known as "noncovalent interactions"). The article could be called "noncovalent bond" as far as I'm concerned, but there should only be one article. --Itub 09:18, 10 April 2007 (UTC)
thread_title:  Merging with [[intermolecular interaction]] 

message: Hi there, I'm a university lecturer in Physical Organic Chemistry with specialisation in the study of non-covalent interactions and have read the discussion on this page with much interest.
With regards to the spelling of non-covalent...the hyphenated version should be preferred, as in all correct English usage of the non- prefix
Also the term "non-covalent BOND", should be dropped entirely, as it is an inaccurate description. The phrase bond should be restricted to cases where electrons are shared between the orbitals of different interconnected atoms. A weak transient interaction between two function groups is exactly that, AN INTERACTION, there is no (or very little) sharing or swapping of electron obitals. At the extremes of non-covalent interactions, more orbital overlap might occur and one might regard such a state as a weak covalent, dative or ionic situation. Indeed such a continuum from non-covalent interactions at one end of the scale to ionic at the other seems reasonable.
One further point, is an interaction between two oppositely charged ions correctly described by the word bond? I would argue not, since ionic interactions tend not to be directional, unlike dative and covalent bonds that have directionality enforced by the geometry of the orbitals involved. Thus, I am firmly of the opinion that the usage of the word bond should be restricted to examples where electron sharing is occurring, i.e. covalent and dative circumstances only.
I agree with the comments on "intermolecular interactions vs noncovalent interactions"...'intermolecular interaction' is not as encompassing as an article on non-covalent interactions in general that includes intramolecular interactions that operate with the same underlying physical princples as intermolecular interactions. Referring to the discussion as to whether the topics non-covalent interactions, non-covalent bonds etc should be merged, well yes they should, there is no difference between these topics, apart from the fact that 'non-covalent interaction' is the most appropriate broad description of this phenomenon; as was correctly pointed out above 'non-covalent interaction' importantly includes repulsive interactions.
I also note that textbooks very rarely present the current state-of-the-art of understanding. I would especially frown upon using a biological textbook as primary source of information regarding this topic in *chemistry*.
I hope that these comments have clarified the situation for you and that other people out there agree and enforce the hopefully sensible reasoning that I have laid down here.
--fray_bentos 16:24, 8 May 2008 (UTC)
replies: text: @Bduke: I have eradicated the incorrect links to Waal's and Waals' (both spelling errors). I don't know if the redirects should be deleted or not.
Jcwf (talk) 01:53, 2 August 2008 (UTC)
thread_title: New discussion on merge

message: As discussed previously on this talk page, the name change for this page is reflecting a more accurate description of the page content.  Future revisions that further reflect the more accurate description will be coming shortly.
AviMole602 (talk) 15:24, 11 November 2013 (UTC)
thread_title: Reason for Renaming Page

message: Bisoxo (Jacob Geri), reviewing Non Covalent Interactions
Content
1.	Is the introductory section accessible for non-experts?
The introductory section is accessible to non-experts. The first paragraph contains an unnecessary unit conversion, however, which would only serve to distract readers. In addition, the last several sentences do not come across as authoritative; it would be better to say that non-covalent interactions are often broadly divided among the four different forces. Also notable is that all the examples in the introductory section relate to supermolecular chemistry, but non-covalent interactions are what give rise to the physical properties that nonexpert readers can relate to, such as the boiling point of liquids, solvent dissolving power, gecko’s ability to walk up glass windows, etc.
2.	Do the contents of each section justify its length?
Yes. The article as a whole is built as a top-level description of noncovalent interactions, and most subsections have sufficient but not excessive content. However, I think that the protein folding section is too long and that the protein structure section could be folded into the protein folding section. Similarly, “Drug Design” and “Enzymatic Function” should be combined and considerably shortened due to the considerable similarity in their topics. 
3.	Are all the important terms/concepts linked to their respective Wikipedia pages for further reference?
Yes, the article is decorated with such intra-wiki links and most of the sections contain links to main pages. A main article link for Protein Structure and Drug Design would be nice. 
4.	Are the highlighted examples appropriate?
This part of the peer review is broken into the article’s sections.
Electrostatic/Ionic: In the first example, there is a clear typo in that fluoride is F-  rather than F+. In the next example, the explanation of acetic acid as being “commonly known as vinegar” is unnecessary, and would be better served by an internal link. Generally speaking the purpose of this example is very confusing because the charge is not localized on a single atom at all, and is delocalized across the carbonate moiety. Perhaps an alkoxide would be a better example?
Dipole: A major error in this section is the parenthetic of acetone as the former main ingredient in nail polish remover. It is still the main ingredient. The example is  otherwise quite useful. The hydrogen bonding example is also quite good, but should mention that hydrogen bonds do contain a small covalent component; similarly, the halogen bond example is well chosen.
Π-effects: This section has good examples as well, but some explanation of how π-stacking works is needed. 
Van der Waals: The explanation of how this works is completely wrong. The authors should read the associated article… electron-electron repulsion reduces intermolecular interaction. 
Applications: The examples in this section are well chosen, but are ALL from biochemistry. Some non-biochemical examples are warranted. 
5.	Is the content duplicative of any other content already on Wikipedia?
Inasmuch as the article is in ways a high level article which collects other subjects covered by Wikipedia, it is duplicative. However, it provides a useful summary of that information and organizes it into a single jumping off point from which users can follow the included links to more detailed articles. Through this, the article offers considerable value to Wikipedia. 
Figures
1.	Are the figures original and of high quality?
Yes. I have no problems with the figures included in the article, and especially like the efficient inclusion of nonoriginal figures from Wikimedia. I would note, however, that the figure titled Enzymatic Transition State Stabilization is quite confusing. Where does the new methyl group come from? I understand that the incoming CH3 group is implied by the dashed line, but the fate of all the reactants and products are not clearly shown. 
2.	Are the figures informative and add to the text?
Yes. The figures inform the text and are relevant to the relative sections. All figures are directly referenced by the text of the article and the captions are informative for a reader skimming through the article. 
3.	Are the Chemdraw structures chemically accurate, aligned, and easy to read?
Yes, but again the transition state stabilization figure is quite confusing. I strongly recommend that this be corrected. Also, a minor problem with the chemdraw figures is that they use the default settings; I would recommend using the template favored by ACS Catalysis, which is known for its insistence on beautiful chemical structures. 
References
1.	Are the references complete (≥8)?
Yes, there are twelve references spread through the article. 
2.	Are the references inclusive of non-journal sources?
Yes, the references include cited books and even links to freely available, open access book chapters from Wiley. 
Overall Presentation
	
Overall, the article contains a sufficient amount of content to provide coverage of the topic. The figures are well chosen, and aside from the last figure are of sufficient quality; incorporation of well-chosen secondary figures was done with good taste. However, the article still needs work: major sections need to be combined or eliminated in the applications section, and there are many examples of confusing or unclear explanations outlined above. A more thorough treatment of dispersion forces is desperately needed, as these forces are very important but only one sentence describing the underlying physics is given. Applications from areas beyond biochemistry are also needed, as are explanations of how π interactions are actually exploited in practice (such as iron N2 model complexes, protein structure organization, etc.).
Bisoxo (talk) 20:07, 4 November 2013 (UTC)
thread_title: Peer Review #2

message: UMChemProfessor (talk) 02:21, 5 November 2013 (UTC)
thread_title: Additional Comments

message: I took a look at Cockroft & Hunter (2007) cited by the halogen bonding section but failed to find any discussion about the distinction between the 2 concepts.  The paper only has a section on Aromatic–halogen interactions but doesn't mention "halogen bond" at all, let alone being particular about the distinction.   In fact, that citing paragraph on the Wikipedia article is the only place I've seen that makes the distinction.  But I'm coming from a physics background and not very familiar with the jargon here.  So it would be nice if someone can add a reference to a textbook or some review article that goes into the distinction.  Thanks. --D昌양 (Talk) 08:27, 21 July 2017 (UTC)
thread_title:  Halogen bonding vs. Halogen-aromatic interaction 

message: ===Response:  Peer Reviewer #1===
The sandbox previously linked "covalent bond" in the opening sentence, and directly contrasted non-covalent interactions as not the sharing of electrons but rather an electromagnetic/electrostatic interaction that does not involve sharing.  We feel that is an appropriate distinction between the two, and if readers desire to look more into the differences, they can study the link to covalent bonds.
To the applications part, we agree that there are not enough examples outside of biology.  We also agree that many items that we state in the second half of our introduction are repeated in the applications section.  We have modified the wording and added examples that are less biochemistry related, yet still easy to understand and relate to.
For the concern regarding dipole-dipole interactions, we did further research and decided to more accurately break up the categories into electrostatic and van der Waals forces, of which dipole-dipole fits into.  We hope that this may be easier to understand organizationally, but realize that hydrogen bonding is now not associated with dipole-dipole interactions and is instead listed under electrostatic.  This is due to the van der Waals force page listing it as the forces outside of electrostatic, hydrogen bonding, and covalent bonding.  To stay consistent, as well as distinguish the relative strengths between H-bonding and other dipole-dipole interactions, we felt that this organization was appropriate.
Regarding the hydrophobic effect, this section was indeed added to our page.  However, it was not discussed in great detail because a Wikipage has already been created for this effect.  Since our page serves as a starting point for all of the non-covalent interactions, we feel that a brief summary is appropriate for this section, with a link to a more detailed description.
As for π-effects, we agree that the pi-interaction  page should be linked, and has been added to our Wikipage.
In regards to Applications, the title has been changed to “Examples.”
A link to “protein structure” has been added, as suggested. 
An image was created for the “Drug Design” section using a commonly used local anesthetic, indicating relevant non-covalent interactions as they pertain to various chemical moieties.
===Response:  Peer Reviewer #2===
The unit conversion is simply to make more clear the amount of energy needed to break a non-covalent bond to readers with little chemistry knowledge.  Since the “calorie” is more easily understood than “kcal/mol”, we feel this is still appropriate to leave in for readers with lesser chemistry knowledge.
We have added non-biochemistry and non-supermolecular chemistry examples.
As for using acetate as the example for ionic bonds, we will change the molecule to reduce any possible confusion.
To respond to your comment regarding acetone in nail polish remover, many companies have actually phased out acetone in nail polish removers due to its possible link to liver damage and replaced it with ethyl acetate.  Since some acetone-containing nail polish removers still may exist, we have modified our statement.  However, we don’t feel that this is a major flaw in our overall argument.
With regards to further explanation of π-stacking, we feel that the link to the pi interaction page is sufficient, and no further detail is needed on our page (since there is already a well-written page on the subject).
Protein folding: We agree that the page was a bit heavy on the biochemistry examples. As such, the enzymatic function section has been eliminated and the protein structure and folding sections were combined. The comment was made that the protein segment was a bit long, but we have elected to keep the majority of the section as an example showing the interplay between the various non-covalent interactions in biological systems. It is also designed as a jump-off point with several internal links to related concepts such as “hydrophobic collapse,” “sterics,” “strain,” and the various orders of protein structures which may be of interest to the novice chemist.
The confusing “enzyme catalysis” chemdraw image was also removed.
A section was added regarding the non-covalent interactions (intermolecular forces) and their associated effects on boiling point – a non-biological application. Additional figures were also included.
===Response:  Additional comments===
We agree that consistency is needed in the ChemDraw structures of the benzene molecules, and as a result have changed them to be consistent.  Thank you for your input!
===Response to ChemLibrarian===
We have modified pictures to be mainly .png and of appropriate sizes and locations to make it easier and clearer to read through.  Your tutorial was very helpful in doing this!  We have also changed the way that linking is organized throughout our page according to more common practices. 
Note: These changes and responses were made by both contributors - I have just pasted the externally compiled responses GoBlue18 (talk) 09:14, 11 November 2013 (UTC)
thread_title: Peer review and responses during the educational assignment in Fall 2013

message: We have modified pictures to be mainly .png and of appropriate sizes and locations to make it easier and clearer to read through.  Your tutorial was very helpful in doing this!  We have also changed the way that linking is organized throughout our page according to more common practices. 
Note: These changes and responses were made by both contributors - I have just pasted the externally compiled responses GoBlue18 (talk) 09:14, 11 November 2013 (UTC)
thread_title: Response to ChemLibrarian

message: In the picture comparing sodium n-butoxide vs. n-butanol vs. diethyl ether, the strongest NI and their boiling points, the molecules shown are actually sodium n-propoxide and n-propanol. Can anyone correct this? KingisNitro (talk) 21:24, 18 June 2018 (UTC)
thread_title:  Boiling point vs. the interaction type