Sunday, 30 January 2011

Lab Mishaps No. 2 - The t-BuLi incident


            Following a Saturday of doing very little whatsoever, I thought I would write a new lab mishap. This is one of my favourites partly because it is mildly cretinous and partly because of who did it. A colleague of mine, who I won’t name, while he is an excellent chemist, is prone to fairly regular bouts of stupidity. Just to put into perspective what I mean, this is a man who on a work trip to France last year uttered the immortal phrase “Wasn’t Joan of Arc one of Henry VIII’s eight wives?” I won’t go into how many things are wrong with this sentence, suffice to say it is completely ridiculous.

             This particular colleague works with ferrocene, a dark red compound which will stain your hands if you are not careful. He is not, and now has strange blotches on his hands on a fairly regular basis. In order to make almost anything from ferrocene itself, one requires a strong base of which the most popular is our good friend tert-butyl lithium. This is not nice stuff, and will spontaneously ignite in air to the point that the end of a needle that has been in t-BuLi will normally have a nice flame burning at the end of it when removed from the bottle. 

When you buy t-BuLi (or any other BuLi for that matter) from anywhere, it comes as a solution in a solvent (normally an alkane like pentane or hexane) which you carefully add to your reaction via a syringe at low temperature (-78 oC is the standard). My esteemed colleague in his infinite wisdom saw that his reaction called for a 1.6M solution of t-BuLi to be added to his reaction and immediately assumed that the stuff in his bottle was the pure stuff. This would be a prudent observation to make had it have not been for the label on the side of the bottle telling him what exactly was in there.

Anyway, moving on to the moronic part. My dear colleague then proceeds to get a dropping funnel and carefully fill it with dry, freshly distilled tetrahydrofuran. THF has a boiling point of 70 oC or so if I remember correctly so this solvent was substantially above room temperature. A syringe full of t-BuLi is then deposited into said solvent at which point the whole lot sets on fire, a fire extinguisher is brandished and the rest of his day was spent clearing up after the extinguisher and listening to us essentially laugh in his face. Fun was had by all.

Back in the lab tomorrow morning, should hopefully be a fairly uneventful week, fingers crossed. Saying that, my after work French lessons start tomorrow night as well which could also be cause for some unsolicited ranting on my part. Who knows?

5 comments:

  1. Is it too soon after the UCLA incident to be telling funny tBuLi stories?

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  2. I am aware of the incident at UCLA, and while it was a terrible accident this was under completely different circumstances. In fact, the only connection between this and that is the reagent involved. Would you like me to change the title to the diethylzinc or the trimethylaluminium incident to avoid further comparison?

    I mean no offence whatsoever posting this. I try my best to write in a humourous/interesting manner but hopefully people also take away the fact that so easily chemistry can be really dangerous if the correct precautions are not taken.

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  3. he should have known that tBuLi readily reacts with THF. (Even nBuLi is not that stable in THF at RT).

    I had a colleague who once tried to run a reaction in refluxing 10M nBuLi on a large scale, on a heating mantle... Yes, we needed a new hood afterwards.

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  4. Oh, there was absolutely nothing wrong with what you wrote! Humor/irony usually doesn't come across very well in comments on blogs.

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  5. You shouldn't trust the writing on the bottle as to concentration (even if you look.) Titrate!

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