Chemical Forums
Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: jenny on November 13, 2004, 06:57:31 PM
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I have an 1H NMR Spectrum for my solid unknown. in CDCL3 solvent. I have figured it to be aromatic per tests in lab. There is sextet connected to a doublet, maybe they are a multiplet, but they almost seem separate. the doublet is from 7.1-7.2 and the sextet 7.1-7.37. I've assumed a benzing ring. then I have a singlet slightly under 5.6 This is what throws me off. This category is vinyl, or poss. phenol. I was assuming a phenol yet my m.p. is 93 degrees. and it was insoluble to NaOH. *delete me* Just head me in the right direction because I am stuck. I was a fishlike odor, crystallike/dense. Any My IR spectrum has a peak at 3000
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Get a mass spec. Then you can try IR and you can still get a carbon.
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an IR would help a lot
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Thank you. I do actually have an IR spectrum but I'm having a hard time understanding it. I went to a website link from a prev. message that you provided for IR spec. that helped. I appreciate your effort, I will just keep trying. Thx. :-\
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The IR peak around 3000 cm-1 probably corresponds to alkyl C-H stretch, but that doesn't tell you too much. Do you have a weak/medium intensity IR peak around 3300?
Have you done any tests to tell if you have a nitrogen in your compound?
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in lab we followed a flow chart and after all of the tests, I concluded that my solid is aromatic. We were provided with IR spec (thin film) NMR 1H and 13C NMR. I'm not sure what tests could have been performed for nitrogen. I have an IR peak at 1600, 1500 and 1300. I just have to study this more to understand it. Sure is complicating. Thanks!!
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Those IR stretches sound like aromatics to me, they are at least in the right range for it.
How many carbons do you see in the 13C spectrum? Do you have just a regular 13C or do you have DEPT as well?
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In the 13C spec I have a carbon at 144, a triplet at 128.6, 128.4, and 126.4 and my solvent CDCl3 as a triplet at about 77ppm. I'm believe it is aromatic but I have to figure out the actual compound. The stretch on the 1H NMR at 5.58 is throwing me off. I do appreciate your time in helping me. I have a huge test tomorrow trying to figure this out and learn the substitution and elimination reaction mechanisms has me overwhelmed. Thanks.
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Are those all of the peaks in the 13C and 1H NMRs? The 1H NMR signal at ~5 is probably from a benzylic proton or something, although it is a little bit off for that even.
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I finally figured it to be triphenylmethane. I had to figure out the ratio of carbons and protons. The singlet at 5.6ppm indicates the proton not attached to the benzene rings. I think. Thanks for helping me brainstorm.
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I love figuring out compounds
1 suggestion: if u wanna know if there is a benzene ring, look for the overtone around 1600-2000, and their confirm it with the peaks at 600-1000. This will tell u the type ob substitution of the ring, if any is present.