Wednesday, December 16, 2009

Salvaging a Spill

This happened at the beginning of the summer, and I imagine it happens to every chemist at some point in their career: the unfortuitous drop! For me I was rotovaping my final purified product when the keck clamp failed. Or rather, I was using the metal clamp on the rotovap which apparently didn't fit the lip of the bump trap. The next thing I know an oil of product is swimming in the water bath along with god knows what else.
One of my other lab mates handed me the largest separator funnel we had, and I started collecting the water out of the bath into Erlenmeyers. After a hefty amount of ethyl acetate I was able to retrieve delicious organic product. Here are some pictures of the ordeal:

















This isn't really a kludge, but it does remind me of There, I Fixed It.

Thursday, December 10, 2009

Crystals in Organic Chemistry

I recently had a seminar presentation which took a good chunk of time away from lab work. When I came back, a number of my flasks had crystals growing. Here's a few:














(S)-3-imidazol-1-yl-2,2'-methoxy-1,1'-bisnaphthyl














(S)-3-hydroxyborane-2,2'-methoxy-1,1'-bisnaphthyl

Finally, I've been saving the aqueous washes from all my reactions with methyl iodide. The clear solution of water turns darker and darker of a few days as iodide is oxidized to elemental iodine. Iodine has captured my heart over the past months. It has this ROYAL PURPLE color in non-polar solvents and this ugly brown color in water. I intentionally have been letting the aqueous extracts sit around so I can grow iodine crystals- which look pretty metallic- oh periodic trends.

Friday, December 4, 2009

Combat Zone
















I love coming across published gems with a sense of humor.
Found this one by Jencks in Chem. Soc. Rev., 1981, 10, 345-375

It's a depiction of the dichotomous SN1/SN2 mechanisms and examples of borderline reactions in the "COMBAT ZONE." The defining feature of borderline reactions are those which show intermediate order in the nucleophile. SN1 reactions should show a rate independent of nucleophile concentration. SN2 reactions should show a rate directly dependent on the nucleophile concentration. Stuff in the middle can be explained as concurrent SN1 and SN2 reactions or as proceeding through some other scheme of intermediates.

Being in a synthetic organic lab, I'm not a fan of anything less than SN2. Why on Earth would I want racemization?!