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This is an old revision of this page, as edited by 64.134.168.97 (talk) at 18:48, 24 June 2012 (→‎We need an article for chemical intermediates: new section). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

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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)[reply]

rename to reactive intermediate

This article used to be called reactive intermediate but I am unable to find out how the name switch was made or when. The IUPAC only defines the phrase intermediate and does not mention reaction intermediate. In my view a reaction intermediate can be any intermediate, not limited to short lived species. V8rik (talk) 21:46, 1 February 2009 (UTC)[reply]

I agree that reaction intermediate need not indicate that the species is short-lived. This is perhaps most true in biochemistry, where many fairly stable compounds are produced, but are still considered intermediates since their ultimate fate is to be converted into something else. Pdcook (talk) 16:23, 21 October 2009 (UTC)[reply]
I agree, imho, reaction intermediate is a broad term that could include the so-called "reactive intermediate". In any case, the Gold Book does equate "intermediate" to "reaction intermdiate" but does not mention "reactive intermediate" at all. Btw this article could benefit from some work. Anyone? Knights who say ni (talk) 23:59, 21 October 2009 (UTC)[reply]


Time scale and conditions

The confusion comes from the word reaction not intermediate

On the macroscopic scale, a chemical reaction is an occurrence where a set of pure substances called reactants gives one set of products. The same set of reactants may also give competing products but there is only one chemical equation per chemical reaction;

On the macroscopic scale, a reaction intermediate occurs in a multi-step synthesis, which is a series of chemical reactions (each with its own chemical equation) where a product of one reaction is used within a new set of reactants for the next chemical reaction performed.

Any product in a multi-step reaction that is used in a subsequent reaction is called an intermediate within a series of chemical reactions. Sometimes the expression reaction intermediate gets used loosely when talking about individual reactions in the sequence.

A reactive intermediate is one that is not usually isolated during this sequence of reactions and is kept in solution or at low temperature, or under conditions where it does not react with air or water, etc.

Since the pharmaceutical industry uses a huge panoply of multi-step syntheses, I suspect that that is where intermediate in the pharmaceutical industry was tacked on to just about every chemical substance in Wiki.

In the Kinetics chapter of general chemistry texts you can find what the Gold book is talking about when it gives another definition of intermediate in elementary reaction, which is a series of elementary steps (reactions) envisaged on the molecular (or microscopic) scale. Wiki does a rather good job in describing the idea of reaction mechanism on the microscopic scale but it seems to be spread out over too much individual material that the big picture might be lost on beginners. Laburke (talk) 23:01, 16 January 2012 (UTC)[reply]

Sorry! I meant to say 3 paragraphs above, "Within the context of reaction intermediates in macroscopic, multi-step syntheses, some refer to a reactive intermediate as one..." This is NOT the IUPAC or text book definition (Anslyn & Dougherty p.52) of reactive intermediate within the microscopic, molecular mechanism context. BTW someone copied over this "Reaction intermediate" page to "Reactive intermediate"Laburke (talk) 02:01, 17 January 2012 (UTC)[reply]

We need an article for chemical intermediates

This article is about short-lived transient species in a reaction. What about chemical intermediates in the industrial sense? Long lived species, that are sold and are building blocks for other molecules. For instance vinyl chloride (intermediate for making PVC).