I think moisture (or water content) is a bigger problem for n-BuLi not just the oxygen content as it catches spontaneous fire when came in contact with air or moisture (C4H9Li + H2O =E2=86' C4H10 + LiOH) and releases highly flammable gas, butane. Butane further react in presence of oxygen to form carbon dioxide and water.
As per the MSDS sheet, LEL for n-BuLi is not available. I also tried to find but no luck.
Again that does not answer your initial question.
Thank you for the initial response; you have confirmed what I noted- the data do not seem to be available.
Allow me to change the question-
The specification for oxygen in cylinder nitrogen is less than 200 ppmv and it goes down as the quality of the nitrogen goes up. Semiconductor grade is < 3 ppmv.
If you were monitoring the oxygen concentration inside a glove box (containment) using nitrogen as the purge gas, what would be the oxygen concentration at which you would say (IN YOUR WRITTEN SOP) that work with a pyrophor can begin.
It would be really helpful to have this answer documented with data; ideally peer-reviewed, but hard anecdotal - not just opinion - would be ok.
And, I really do not care about t-BuLi, but used it as an example. Again, I am trying to find support for pyrophor use which is analogous to hydrogen, where the data clearly support <5% being not ignitable no matter the hydrogen concentration.
Thank you for continuing this discussion
Neal, are you speaking the common 1.5% to 1.7% solution in pentane? The LEL of pentane is 1.5% (10% LEL, 1,500 ppm) which doesn't really answer your question about t-BuLi itself. Like you I have searched and the best I could fine was how to isolate t-BuLi solutions to pure crystalline form, but it was never exposed to varying % of oxygen, all was done under argon and/or nitrogen.
Does anyone have any citations for the low limiting oxygen concentration of pyrophoric compounds. I am specifically looking for the oxygen percentage at which compounds such as t-BuLi become non-ignitable. For example, that value is 5% for hydrogen. I have found a reference for silane, but, as is typical for silane, there are a myriad of confounding issues.
I have searched both SciFinder and Science Direct and have not found helpful data.
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