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Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: photopearl on June 18, 2021, 05:13:45 PM

Title: Why and how would you recrystallize a product from anhydrous solvent?
Post by: photopearl on June 18, 2021, 05:13:45 PM

I am an undergraduate researcher in a photochemistry lab. I am currently studying the photo physical changes that occur upon thionation of naphthalimide derivatives. The current procedure I'm following results in a tar-like substance. The next step is to crash out the product in chloroform and methanol. The result of filtering is a very static-y black powder. The NMR has shown that the solid I have is my very impure product (it worked, yay!!!).

The next step in the procedure was to recrystallize the solid in anhydrous ethanol. The paper doesn't give a reason for doing so and a search on google, web of science, and scifinder was not very helpful. Why would you want to recrystallize in anhydrous solvent? And does this have to be done under an inert atmosphere?

Title: Re: Why and how would you recrystallize a product from anhydrous solvent?
Post by: Meter on June 18, 2021, 06:10:06 PM

Water is reactive under certain conditions. Keeping water out of your reactions and work ups helps prevent nasty side reactions.

Title: Re: Why and how would you recrystallize a product from anhydrous solvent?
Post by: rolnor on June 19, 2021, 03:09:01 AM

Its probably not important with anhydrous ethanol.