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kmno4
International Hazard
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"Resonance structures" are only mathematical trick, not existing in reality. It is commonly known, master.
But woelen's " electron 'flips' " are something different and correspond to charge-transfer: really existing phenomenon.
See here, for some informations:
http://en.wikipedia.org/wiki/Intervalence_charge_transfer
or
http://en.wikipedia.org/wiki/Mixed-valence
Слава Україні !
Героям слава !
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AJKOER
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OK, ScienceSquirrel yes and no. More ClO2 in solution and given its ability to readily exit solution (per a decrease in pressure or increase in
temperature, as it does not hydrolyze like Cl2) is where the danger lies. To quote from someone in the business of using ClO2:
Bhupen P.: "When in gas phase about 10 kPa partial pressure, roughly 30% in air ClO2 may decompose from a shock or hotspots into chlorine and oxygen
with explosive force."
Source: http://www.linkedin.com/groups/Is-Clo2-in-Aquous-form-178984...
So even a 10% solution of dissolved ClO2 in solution could potentially rapidly lead to a explosive level of ClO2 and air above the solution (per, for
example, a sharp drop in pressure or increase in temperature)which could further trigger an explosion from a pressure wave or local hot spot. For
safety, keep aqueous solutions of ClO2 cold.
Per another source (see http://www.scribd.com/doc/30120967/Chlorine-Oxygen-Acids-and... ) to quote:
"An equation for calculating the partial pressure of chlorine dioxide above specified chlorine dioxide solutions at various temperatures based
on the data from reference [24] has been developed (25):
pClO2 =(g/L ClO2) e^[10.717−(3102/T)] (1)
where pClO2 is the partial pressure of chlorine dioxide gas in kPa, g/L ClO2 is the chlorine dioxide solution concentration in grams per liter, and T
is the absolute temperature in Kelvin."
This is important as another source (see http://www.google.com/url?sa=t&rct=j&q=%22chlorous%2... ) to quote from page 11, Chlorine dioxide "decomposes explosively at >300 mm Hg
partial pressure" so there is a valid safety concern relating a ClO2's solution concentration (and/or temperature), and proneness to explosion.
[EDIT] Hopefully, the foregoing discussion will foster more knowledge of ClO2 and some of its unique properties (particularly its ability to rapidly
exit solution) to facilate safer experimentation with Chlorine dioxide.
[Edited on 23-5-2013 by AJKOER]
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phlogiston
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Quote: Originally posted by kmno4  |
But woelen's " electron 'flips' " are something different and correspond to charge-transfer: really existing phenomenon.
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Indeed. I just mentioned it because Woelen called it resonance structures, which they aren't.
-----
"If a rocket goes up, who cares where it comes down, that's not my concern said Wernher von Braun" - Tom Lehrer |
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woelen
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@kmno4: If I read your links, then you are suggesting a structure with bridging oxygen atoms between the Cl-atoms instead of an O2Cl...ClO2 structure?
This is what the last link you provided describes.
I cannot draw here, but I then would either suggest a structure like O-Cl-O...O-Cl-O, or even two bridges in parallel to each other with the Cl-atoms
at the end sites, something like
Cl(-O...O-)2Cl ,
where the total charge of this object is -1.
The structure (-O...O-) is not a peroxo structure, but part of an intervalence charge transfer structure as described in the wiki page.
If you have a literature reference for me, then I would like to have that. Then I'll modify my webpage and add the reference to my webpage (of course
not a copy of the article itself, due to copyright ownership issues).
I have the feeling that I am coming closer to the solution of this riddle.
[Edited on 23-5-13 by woelen]
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woelen
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I finally found a reference which mentions the charge transfer between ClO2 and ClO2(-). They did analysis with a special radioactive isotope of
chlorine:
http://pubs.acs.org/doi/abs/10.1021/ja01175a077?journalCode=...
Unfortunately I cannot read the entire article, but the first page gives sufficient information. I still have no 100% certainty about the nature of
the compound, most likely it is something like [Cl(-O...O-)2Cl](-), which is in equilibrium with ClO2 + ClO2(-).
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Bedlasky
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I found document which talks about formation of [Cl2O4]- complex.
https://www.oieau.org/eaudoc/system/files/documents/39/19857...
Similar complex between NO and NO+ was disscused here:
https://www.sciencemadness.org/whisper/viewthread.php?tid=15...
[Edited on 8-3-2021 by Bedlasky]
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woelen
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Interesting read about the Cl2O4(-) complex. In that article it simply is taken for granted, but it certainly is not common knowledge. This complex
allows one to reach very high concentrations of ClO2, bound to a solution of chlorite. I have done further experimenting with this a few months ago
(also with Br2 and NO2). Quite a few oxidizers are capable of oxidizing ClO2(-) to ClO2 in neutral solution and if that is done, you get a nearly
black liquid. I once had a nasty near-explosion from a saturated solution of NaClO2 through which I passed chlorine gas. Suddenly the black liquid
made a lot of loud crackling noises and then the entire contents was ejected from the test tube. Droplets of the black liquid expelled clearly visible
yellow gas. Scary stuff when at such high concentrations.
Cl2 + 2ClO2(-) --> 2Cl(-) + 2ClO2
ClO2 + ClO2(-) <---> Cl2O4(-) (the latter is nearly black when this is done with appr. 30% NaClO2 in water).
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