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My teacher said that OF2 is the third most powerful oxidising agent after F2 and atomic O, but I think O2F2 should be even more oxidising, since it less stable than OF2. I just read on quora that O2F2 is so unstable that it readily oxidises anything that comes in contact even when it is frozen. Also, in case of hydrides of p-block we say that reducing power increases down the group as the tendency to donate H increases due to decreasing thermal stability, so on similar lines, I think O2F2 should be a more powerful oxidant.

Or is it because in OF2, the oxidation state of O atom is +2 (compared to +1 in O2F2), which it wants to get rid of and thus gets reduced, oxidising the other species readily. But if this is true then why is it more stable as we know that stability is inversely proportional to reactivity? Or are the concepts of stability and oxidising power completely unrelated?

I was not able to find the electrode potentials of these species, so how could they be even compared reliably?

Mithoron
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Arnav Upadhyay
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  • Your right. O2F2 has no std. el. potential - it decomposes in very low temp. but even in low temp. it's still stronger. – Mithoron Jan 22 '19 at 20:32
  • related https://chemistry.stackexchange.com/questions/108262/compound-having-highest-standard-reduction-potential https://chemistry.stackexchange.com/questions/102502/what-is-the-strongest-oxidising-agent – Mithoron Jan 22 '19 at 21:28
  • also https://chemistry.stackexchange.com/questions/65079/relative-o-o-bond-lengths-in-o2x2-molecules-x-h-f-cl https://chemistry.stackexchange.com/questions/4624/please-explain-why-dioxygen-difluoride-is-so-dangerous – Mithoron Jan 22 '19 at 21:30
  • and https://en.wikipedia.org/wiki/Oxygen_fluoride https://en.wikipedia.org/wiki/Krypton_difluoride – Mithoron Jan 22 '19 at 21:39
  • In one of the answers, it says that OF2 produced on the decomposition of FOOF is more oxidising only due to the additional O2 produced with it. And that during oxidation by O2F2, the actual job is done by OF2 itself. Does that mean it is actually inappropriate to compare the two since they are essentially the same during the actual reaction? And technically FOOF is the better oxidant since it actually is OF2 plus O2? – Arnav Upadhyay Jan 22 '19 at 22:44
  • No this info seems to be incorrect - it decomposes into O2 and F2. And OF2 is very weak in comparison - it only slowly hydrolyses in water when FOOF sets ice on fire. – Mithoron Jan 22 '19 at 23:30
  • <Of the products formed by the self-decomposition of FOOF, oxygen gas is a pretty strong oxidizer, but it's the least of our worries here. The other product, oxygen difluoride, is almost as strong an oxidizer as dioxygen difluoride, which is only stronger because it's oxygen difluoride plus more oxygen. OF2, , like its FOOF parent, reacts very strongly and exothermically with almost anything, especially water. It will literally burn ice, rapidly;> This is the text from an answer in the 3rd link you shared. This seems to directly contradict your opinion. – Arnav Upadhyay Jan 23 '19 at 11:47
  • It's not an opinion and I put link because these are related posts not necessarily correct. I you'd read the Wikipedia art. then you'd see info with citation to actual paper "(...) decomposes to O2 and F2 close to its normal boiling point of about 216 K.https://pubs.acs.org/doi/abs/10.1021/cr60226a003 – Mithoron Jan 23 '19 at 16:23
  • https://en.wikipedia.org/wiki/Dioxygen_difluoride https://en.wikipedia.org/wiki/Oxygen_difluoride – Mithoron Jan 23 '19 at 16:24

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