Sciencemadness Discussion Board

Oxidatively stable solvent

Cesium Fluoride - 14-3-2012 at 11:59

Hi all,

It's been a while since I've posted here, but I have a question I think you all will be good at answering. I'm doing some electrochemistry and I need to run a cell in the presence of a peroxide salt under high potentials. I am looking for ideas of solvents that display extreme stability under oxidative conditions.

Solvents I have tested that have decomposed include DMSO, alkyl carbonates, and ethylene-glyol-based ethers (DME and other glymes). My only untested idea thus far is siloxanes as I know pump oils have good oxidative stability. Any other suggestions would be much appreciated.

[Edited on 14-3-2012 by Cesium Fluoride]

[Edited on 14-3-2012 by Cesium Fluoride]

497 - 14-3-2012 at 13:05

Fluorocarbons?

Cesium Fluoride - 14-3-2012 at 13:18

Sulfones?

unionised - 14-3-2012 at 14:00

IIRC acetic acid and acetonitrile are quite good.

BromicAcid - 14-3-2012 at 15:55

Carbon tet, AFAIK Mn2O7 and Cl2O7 solutions are stable (as stable as they ever are).

PHILOU Zrealone - 14-3-2012 at 17:08

CO2?
N2O5?

AndersHoveland - 15-3-2012 at 15:58

Water is the most obvious choice, but apparently water is not suitabe for your reaction for some reason, otherwise you would not have asked this question.

There are not many solvents that are both liquid at room temperature, can dissolve ions, and can withstand oxidizing radicals.
Pressurised liquid CO2 might be appropriate. Liquid SO2 is easier to liquify and more polar, but not sure if it can dissolve salts.
A more expensive and less commonly available solvent is perfluorooctane sulfonate. Not sure if it could withstand oxidative radicals.

Dr.Bob - 22-3-2012 at 11:36

NMP might survive, not sure. It is more stable than DMF or DMSO (which will oxidize readily). Diphenyl ether mixtures (DowTherm A) might also work. But they are all oxidizable, and may react.

Ionic liquids might also be good, not sure if they would work in a electrochemical cell or not.

Cesium Fluoride - 26-3-2012 at 12:47

NMP is a good suggestion, thank you.

Very nonpolar things like fluorocarbons or CCl4 are not ideal since it will be hard to find a salt greasy enough for them to dissolve.

AndersHoveland - 26-3-2012 at 20:43

Quote: Originally posted by BromicAcid  
Carbon tet, AFAIK Mn2O7 and Cl2O7 solutions are stable (as stable as they ever are).


Nitrosyl perchlorate, NOClO4, might be considered. Although it is an explosive, it is at least much more stable than N2O5, Cl2O7, or Mn2O7.
http://www.sciencemadness.org/talk/viewthread.php?tid=196
http://web.mit.edu/semenko/Public/Military%20Manuals/RogueSc...

Carbon tetrachloride is not going to be able to dissolve polar or ionic compounds. And it may likely not be completely resistant to oxygen radicals.
Quote:

HClO4 is insoluble in CCl4, and gives upon shaking, a green emulsion, which discolors brown after several minutes welling up under formation of HCl and COCl2 (Vorländer, v. Schilling, Lieb. Ann. 310 [1900] 374). Preparation of solutions of Cl2O7 in CCl4 described in: F. Meyer, Keszler (Ber. 54, [1921] 569).


[Edited on 27-3-2012 by AndersHoveland]