Sciencemadness Discussion Board

KOMe / Potassium Methoxide Safety

wakatutu - 16-7-2020 at 11:12

I would like to try the procedure from Platonov (2002) in which K2CO3 is stirred with methanol at 20C for 6h then filtered, the methanol distilled partially, filtered again to remove carbonates, then distilled further (to dryness even!). K2CO3 dissolves in methanol then disproportionates into KOMe in solution and KHCO3, which is insoluble and precipitates, driving the reaction forward.

My concern is with MSDS sections mentioning that KOMe is unstable above 50C, decomposing explosively. And the BP of methanol is 65C. Obviously I would use vacuum to distill methanol below 50C.

Does anybody have some tips for working safely with methoxides? I think I need some guidance from someone who knows from experience what kind of precautions to take and what sort of conditions to avoid. Thanks!

[Edited on 16-7-2020 by wakatutu]

Metacelsus - 16-7-2020 at 11:31

I've never heard of potassium methoxide decomposing explosively, and I can't find any references for it. (It may decompose at high temperatures, but it won't explode.)

The main risks would be corrosion of materials such as glass, and exothermic reaction with water.

wakatutu - 16-7-2020 at 12:59

This says KOMe decomposes at >50C, and I honestly can't find the reference that says it explodes at 70C. I appreciate your input metacelsus