December 27, 2024, 10:33:24 PM
Forum Rules: Read This Before Posting


Topic: Relating a Hnmr to a possible structure  (Read 11925 times)

0 Members and 1 Guest are viewing this topic.

Offline clarkstill

  • Chemist
  • Full Member
  • *
  • Posts: 477
  • Mole Snacks: +77/-4
Re: Relating a Hnmr to a possible structure
« Reply #15 on: November 16, 2017, 11:18:14 AM »
Pretty sure this isn't what you're looking for. The 1H spectrum should have 12 unique environments by my count (since the amine breaks the symmetry of the thiophene so the aryl groups are non-equivalent) and the 13C should have 22 peaks I think, which yours has nothing like. Whatever you've got seems to be much smaller or more symmetrical.

Offline Sach

  • Regular Member
  • ***
  • Posts: 93
  • Mole Snacks: +2/-0
Re: Relating a Hnmr to a possible structure
« Reply #16 on: November 16, 2017, 12:16:23 PM »
I also thought that the amine would break the symmetry but I wasn't sure if it would really show on C-nmr. I have recently been studying C-nmr to be able to interpret it better (I studied it during graduation which is more than 2y ago now). Thank you all for your input, I appreciate it.

Offline Sach

  • Regular Member
  • ***
  • Posts: 93
  • Mole Snacks: +2/-0
Re: Relating a Hnmr to a possible structure
« Reply #17 on: November 16, 2017, 12:35:11 PM »
I am actually thinking that this C-nmr indicates my molecule without the benzyl carbamate (amine group and protecting group removed).

Offline kriggy

  • Chemist
  • Sr. Member
  • *
  • Posts: 1520
  • Mole Snacks: +136/-16
Re: Relating a Hnmr to a possible structure
« Reply #18 on: November 21, 2017, 02:41:09 AM »
yeah the sample conc. seems low. I suggest using more sample and maybe more scans as well.

btw if you want to be sure that you have the amine group, the easiest way is to use ninhydrine stain. Its cheap and most likely you have some lying randomly in cabinet

Offline Sach

  • Regular Member
  • ***
  • Posts: 93
  • Mole Snacks: +2/-0
Re: Relating a Hnmr to a possible structure
« Reply #19 on: November 21, 2017, 11:38:56 AM »
Ok thank you

Offline Sach

  • Regular Member
  • ***
  • Posts: 93
  • Mole Snacks: +2/-0
Re: Relating a Hnmr to a possible structure
« Reply #20 on: November 26, 2017, 05:57:50 AM »
In the attachment, you can find the infrared spectrum I obtained. I want to see whether or not it is the IR spectrum of the molecule you can find in the attachment (unprotected amine because I suspect that the protecting group is removed according the C-nmr). According to me, there is a peak (2 peaks) at 3300-3400 that indicate a primary amine. There also seems to be ester (peaks around 1750). I was thinking that the peaks around 3000 should stand for aromatic hydrocarbons but they should be above 3000 while in this case, they are below 3000.
Now I have the H-nmr, C-nmr and the IR but I am still not completely able to relate it to a molecule. Can someone help me further with this?
Thnx in advance guys

Sponsored Links