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"Quantum models"[edit]

The section on "Quantum models" has absolutely no relevance to photodissociation as it refers to the initial stages of photosynthesis where light is absorbed and transferred to reaction centers prior to charge separation. Move it to another page, I suggest — Preceding unsigned comment added by (talk) 07:26, 12 April 2012 (UTC)

Merge from photolysis[edit]

This page and photolysis essentially duplicate each other. I think the term Photodissociation is probably the simpler one and hence propose merging to here.--NHSavage 19:49, 8 September 2006 (UTC)

I think both terms are not equal, in the sense that photolysis describes a process of a more industrious nature. Photodissociation is certainly the term used in astronomy, which is described in this page. I therefore support this proposal. Errabee 20:07, 8 September 2006 (UTC)
done.--NHSavage 18:24, 11 September 2006 (UTC)

Can someone REVERT the MERGE ? they are two separate articles : In contrast to fotolyses only 1 molecul is broken down in fotodissociation. (from the NL version) reg. Mion 01:52, 7 October 2006 (UTC)

I believe that the NL article is wrong. I have always seen the two terms used as having the same meaning. Also the quote you give does not make any sense to me. How can more than one molecule be broken down by a photon? If I am wrong please find a reference to show it (ideally a standard university textbook). Meanwhile I will try and find one which says the two are the same. Even if there is a subtle difference in the correct use of the two terms (and I may have been using the two as synonyms incorrectly for a decade) I would still argue that the two articles should remain merged as there is not sufficient content to justify two seperate articles on the same topic. --NHSavage 07:28, 7 October 2006 (UTC)
An example of the two terms being used as synonmys is here. This is part of web article on atmospheric chemistry by Chris McLinden who has been working on electromagnetic radiation in the atmosphere for a long time. I still haven't found a proper reference though.--NHSavage 07:37, 7 October 2006 (UTC)
As the writer of that Dutch sentence, I concur that the two are the same process. I meant to say that there is a subtle difference between the two: in astronomy, the term photodissociation is exclusively used, whereas in biology (photosynthesis) the term photolysis is exclusively used. I never meant to say that more than one molecule could be broken down by the same photon. At the time, it seemed to me (OR!) that photodissociation is a process used when densities are low and photodissociation events are scarce (a chance occurrence on individual molecular basis) whereas photolysis is used in a more industrious context (sort of an assembly line). Errabee 11:08, 7 October 2006 (UTC)
That's fine. In atmospheric chemistry the two terms are used intechangeably in my experience, although most people tend to use photolysis not photodissocaition.--NHSavage 12:04, 7 October 2006 (UTC)
So, one is more common used, and the other is a better description of the process ? . Mion 12:06, 7 October 2006 (UTC)
No, not exactly. The usage depends on the context. In astronomy, photodissociation is used exclusively (in the group in which I was working, we didn't even think about using photolysis); in atmospheric chemistry the term is apparently used interchangeably; and in biology, photolysis is used. That nicely reflects my density theory :) Errabee 12:58, 7 October 2006 (UTC)
You say tom-ay-toe and I say tom-ah-toe. Notably the IUPAC Gold book only has a definition for the term photolysis so that is probably the prefered term for chemistry. Where the actual page is does not matter IMHO as both terms are in the first line and one redirects to the other.--NHSavage 14:11, 7 October 2006 (UTC)
OK, clear enough, thanks. Mion 15:06, 7 October 2006 (UTC)

Higher energies[edit]

As the article on supernovae links to this page, shouldn't it also mention the photodissociation of nuclei?

I have never heard of supernovae photodissociating nuclei. As I have always understood, supernovae are the only way atoms heavier than oxygen can be formed (through fusion). The reverse proces (iron into helium, no less) seems unlikely to me, and I would hesitate to quote that. Disclaimer: I am not an astronomer; I just happened to do some scientific research into an astronomy related subject, and took some courses of astronomy of interest to my field of expertise (which did not include supernovae). Errabee 00:09, 6 October 2006 (UTC)
Actually, the information on Supernovae appears to be incorrect. It is the rebound shockwave that shatters iron atoms into nucleons. That makes it totally unrelated to photodissociation. Errabee 16:39, 6 October 2006 (UTC)


Hi, you marked the photosynthesis section on the photolysis page as needing updating. Can you specify a bit more what is needed? The section is based on two 2005 textbooks, and I've checked the corresponding chapter in a 2007 textbook but I can see no additional information (although that might be because it's a general biology textbook and less detailed than e.g. a plant physiology textbook might be). Also, I've checked on PubMed for photolysis + photosynthesis and the latest review related to the topic dates from 2001. So I'm not sure what new information is out there and where to find it. Can you specify it a bit more? Thanks! - tameeria 20:28, 4 May 2007 (UTC)


Thanks for verifying the tag. The new work reference is also in the news, at This confirms my observations and model on the photodissociation of large molecules, while I was with the MPQ, at Garching by Muenchen, in 1983. Reference there is MPQ-58. Gerck, E.: Development of New Iodine Photodissociation Lasers. Edgerck 22:00, 4 May 2007 (UTC)


Ah, I see, thanks for the link. And hot off the presses, too! I don't have access to Nature though until I get the time to check out the library, and looking at the abstract, I suspect some of the physics stuff may be over my head. (I was always better at biology than physics!) Since you seem to be more familiar with the subject, feel free to update the article! - tameeria 03:42, 5 May 2007 (UTC)


I'll update the article, thanks. Please tell me what you think when you see the changes. I do want it to be accessible in the biology field, and that's why I originally put the update notice for someone else to do it. Was interesting to see how quickly it was picked up! Edgerck 02:03, 6 May 2007 (UTC)

I just updated the article. Wonder what you all think. I called the current model the "conventional model" so as not to introduce new terminology. Edgerck 22:28, 8 May 2007 (UTC)

WikiProject class rating[edit]

This article was automatically assessed because at least one WikiProject had rated the article as start, and the rating on other projects was brought up to start class. BetacommandBot 07:55, 10 November 2007 (UTC)


Is there any good reason that this should not be at photolysis? Currently 16 different articles link to photodissociation yet 61 link to photolysis.[1] David D. (Talk) 05:16, 4 March 2008 (UTC)

This article is very poor is it a chemistry, molecular biology or astrophysics article? Definately in need of a clean up.  — Preceding unsigned comment added by (talk) 22:38, 18 August 2011 (UTC) 

Assessment comment[edit]

The comment(s) below were originally left at Talk:Photodissociation/Comments, and are posted here for posterity. Following several discussions in past years, these subpages are now deprecated. The comments may be irrelevant or outdated; if so, please feel free to remove this section.

"Photolysis" redirects here (intro bio topic) - tameeria 21:26, 5 May 2007 (UTC)

Last edited at 21:26, 5 May 2007 (UTC). Substituted at 02:54, 30 April 2016 (UTC)