If anyone is familiar with Sandmeyer reactions, I just completed one for my lab. We tried to synthesize 4-chlorotoluene by combining solutions of copper (I) chloride and diazonium chloride solution. We also added ether and sodium hydroxide to remove p-cresol from the solution. Our IR spectrum shows that our final product has a peak at 1500 cm-1 suggesting that an aromatic ring present. We had a peak at 850 cm-1 suggesting that we also had a para di-substituted aromatic ring which I believe is 4-chlorotoluene. I am perplexed to why we are getting feedback suggesting our final product contains aromatic rings. Could it be that we did not distill our product enough or did we not dry out the ether enough? I am appealing to anyone that is familiar with Sandmeyer reactions. Thanks.
You are in the 2nd semester of Organic, correct? I wish I could help you but I don't remember going over Sandmeyer reactions, but I only took the 1st semester. I remember we got up to Benzene and that was like chapter 13. I was able to pull a B out of that class and was damn lucky to get it. I dropped the 2nd semester and took Biochemistry instead. Bio was probably just as hard or even harder than Organic. I have often wondered many times what it would have been like to take the 2nd semester of Organic instead of Biochemistry - guess I will never know. Anyway, my musing about my past isn't going to help you. Maybe someone who took the 2nd semester will respond.
Yes this is organic 2. Im doing well in the class, but i like this kind of stuff. I already turned in the lab for this experiment, but I get all bent out of shape when things dont work the way i expect, but that's science.
I'm pretty sure what you got was correct. The aromatic ring should appear in the 1500-1700ppm range of the IR with anything under 1000 being the fingerprint region. This does not indicate that you have two benzene rings by any means. Sandmeyer just goes through one when you add N2 and then it just becomes replaced with CuCl in this case. Should be fine.
You do realize that IR spec will show multiple peaks for one molecule right? It shows energy of bonds.
i don't know if your IR is correct or not, but we often found one of the keys to getting a good IR was to wait until someone accidentally got all the way through the lab and actually ended up with the correct IR printout and then just made copies of that. if it was your IR that was used, even better. unlikely.
i guess i was confused because my IR chart was showing a di-substituted aromatic ring and an aromatic ring. I for some reason thought it was one or the other.
IR shows the vibrational frequency of certain bonds. Benzene has all c-c bonds with the same energy. A ring with substitutions will have other peaks representing the substitutions on the ring. The bonds surrounding the carbon that is substituted on will also have a difference energy because you have something other than hydrogen changing the electro negativity of that particular carbon.
Granted, it was 17 years ago so my recollections are a little fuzzy but I remember a sh!tload of amino acids and their various reactions plus all kinds of stuff relating to DNA, for starters. Too bad you were in grade school back then because I sure could have used your help - I might have been able to pull an A if you had tutored me, f4p.
I'm currently both in Organic Chemistry 2 and Biochemistry and I'll say Organic 2 requires significantly more analytical thinking. Biochemistry isn't easy but you can get by on memorization, reading the book, and deducing and guessing (our exams are multiple choice but it may have been different for you). I aced Organic 1 (yeah, brag about it) but it really is just baby O-Chem 2. Every exam get more difficult asthe reagents keep stacking up, probably up to more than 200 already you need to know.
that's what i remember thinking when i looked back at o-chem 1 after finishing o-chem 2. our first 2 tests in o-chem 1 weren't much more than the ap chemistry i took in high school. the 3rd test was a little harder because we didn't realize we actually needed to know all the solvents for all the reactions and that made it tough (we certainly learned them for the final). but man, o-chem 2. i needed a 56.5 on the final for an A and i got a 58. that final just kicked my ass. now, granted, in biochem i had a friend's notes and tests from the previous semester and quite a few things typed in my calculator which made the tests doable without a ton of studying or going to class much, but man, i don't think that strategy could have worked for o-chem 2. i was there bright and early at 8 a.m. every tuesday and thursday taking good notes and studying the hell out of those notes for the tests.
