Sodium Nitroprusside Synthesis

I performed two attempts at synthesizing sodium nitroprusside recently. My first attempt was mostly failure with a minuscule yield. It was soon lost to acts of frustration during the recrystallizing procedure to purify.

The second attempt I performed a full sized batch according to a procedure I followed from the 1800s or something. These were in my book, horrible inaccurate and vague instructions. So, I split the batch into several equal portions to experiment with modifications to the procedures in the next steps. Two of these separated batches were complete failures, but yesterday I found the forgotten third flask which I had placed off to the side in the dark to avoid light decomposition.

I treated this batch through several filtrations and careful evaporation yesterday and through the night last night. To my excitement I come down to my office finding this. Crystals!!!

This is a huge win for me since I had so many frustrations trying to get a successful run. I'm going through some hard times in my personal life right now, so finding something as simple as a crystallized solution of a substance I've been struggling to successfully synthesize brings a bit of much needed happiness.

I will attempt to recreate the steps I performed in a "How-to" post later on.

I've got the dried crystals. The yield is approximately 30% which is a lot better than my first attempt yield of less than 15%

I'm also noting that the successful batch measures at approximately 8 pH.

Quote: Originally posted by Boffis

Nice looking product there D.A.F.. I look forward to reading your experimental write-up. What do you intend to do with it? It has some really interesting properties because the -NO group is quite laibile and easily replaced by ammonia, amines etc. I think that the nitroprussides are the most interesting of the iron cyanide complexes.