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?