Wednesday, January 16, 2013

Day Nine: Step One is a Success!

Hello, Blogger world (and Dr. Pittman).

Once again, I must apologize for posting my daily blog one day late.  In my defense, yesterday was a very long day and today I did not work in the lab because I accompanied another Interim group to Duke Energy in Seneca, which was a fantastic experience and has given me some things to consider for my future.  Educational opportunities are everywhere.

Yesterday's process was slow but valuable.  We began by preparing GC samples of our Grignard products - in my case, 2-benzylcyclohexanol.  (Note that this is fairly similar to the standard cyclohexanol that we reacted last week.)

ChemSpider 2D Image | 2-Benzylcyclohexanol | C13H18O 

We added water to our reaction flasks, and two separable layers - liquid and solid - formed. We decanted the top layer into a new RB flask, using a sample of that liquid for our GC scan.  The precipitate was left in the flask.

From the first scan of our samples, we determined that all of the cyclohexene oxide had reacted, because the known peak for that compound was not present in the spectrum.  After that, we ran the same samples through the GC but performed mass spectrometry, as well.  My top match for the product mass was the desired compound - yay!

Having concluded that my product solution contained 2-benzylcyclohexanol, I set the purified solution to dry with magnesium sulfate and turned my attention to the leftover, untested product.  Since we believed that some product might have been trapped in the precipitate, I removed the unreacted magnesium by vacuum filtration and treated the solution with 6-M hydrochloric acid until the solution was no longer basic.  This was to ensure that all of the alcohol was indeed protonated and to make it more ether-soluble than aqueous.  I rinsed the solution with ether and separated the organic product from aqueous.  Tomorrow, we will determine if the two solutions match.

Thus far, the most frustrating part about research is having to wait for results before moving on.  It would have been much more time-efficient to perform the acid workup while the first GC scans were in progress, but then, we may have done more work than was necessary if there hadn't actually been desired product in our samples.  There is a lot of trial and error involved, as well, which is distinctly more nerve-wracking than following a set procedure.  On the other hand, taking notes and modifying what we've been given is a very exciting process!  It's cool that we can somewhat customize this research experience - from the number of Keck clips we use on our apparatuses to the compounds we've selected to study.

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