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I am not a chemist, and somehow I cannot find any material on this topic, so I decided to ask here.

I am looking to create a solution with a specified amount/concentration of superoxide ($\ce{O2^.-}$). Can you suggest some compounds that will enable me to "isolate" superoxide in a solution?

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Potassium superoxide (Aldrich) and an equimolar amount of 18-crown-6 ether used to increase solubility were dissolved in dry DMSO.

Role of Hydrogen Bonding in the Active Site of Human Manganese Superoxide Dismutase Biochemistry 2004, 43, 7038-7045

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  • $\begingroup$ I took a read through this paper. I don't understand how this has anything to do with producing superoxide in stable amounts. $\endgroup$ – A.I. Oct 31 '16 at 16:10
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    $\begingroup$ @A.I. They create superoxide solutions in DMSO, which is then added to aqueous solutions. The superoxide is relatively stable in the DMSO solution. $\endgroup$ – DavePhD Oct 31 '16 at 16:14
  • $\begingroup$ OK, so what you're suggesting is to mix $KO_2$ and $C_{12}H_{24}O_6$ in $(CH_3)_2SO$, then the whole thing is added to an acqueous solution, which should have $O_2^{\bar{\cdot}}$. Correct? $\endgroup$ – A.I. Oct 31 '16 at 16:27
  • $\begingroup$ OK, this seem s like a good path. I'll accept this as an answer. This article might also be useful for others reading this. $\endgroup$ – A.I. Oct 31 '16 at 16:32
  • $\begingroup$ @A.I. once it's added to aqueous solution, the superoxide reacts quickly. See "uncatalyzed, second-order rate constant of 440 M-1 s-1." in caption of Fig. 2. In the DMSO, superoxide is dissolved as a separate ion and is relatively stable. In aqueous solution, it is still dissolved as a separate ion, but is unstable, which is why the stock solutions are made in DMSO. $\endgroup$ – DavePhD Oct 31 '16 at 16:41

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