April 18, 2024, 08:18:29 AM
Forum Rules: Read This Before Posting


« previous next »
Pages: [1]   Go Down

Topic: NMR spectrum problem!  (Read 2870 times)

0 Members and 1 Guest are viewing this topic.

Offline bio775

  • New Member
  • **
  • Posts: 5
  • Mole Snacks: +0/-0
NMR spectrum problem!
« on: September 14, 2014, 04:32:12 AM »
Hi! how to figure out this C-13 NMR spectrum:
The peak at 25 ppm in the 13C NMR spectrum of B is most likely to be:

I know that at 25 ppm, is the alkane but I don't know which is the right figure. (I have attached the figure)

I am sure the answer is C but just want to double check. Thanks
Logged

Offline kriggy

  • Chemist
  • Sr. Member
  • *
  • Posts: 1520
  • Mole Snacks: +136/-16
Re: NMR spectrum problem!
« Reply #1 on: September 14, 2014, 06:13:35 AM »
I dont think its C, the presence of ester group changes the shift so 25ppm is way too low IMHO (I had carbons like that around 55)
Logged

Offline bio775

  • New Member
  • **
  • Posts: 5
  • Mole Snacks: +0/-0
Re: NMR spectrum problem!
« Reply #2 on: September 14, 2014, 06:21:10 AM »
But according to the table at 25 ppm is alkane. So, what do I look for?
Logged

Offline Dan

  • Retired Staff
  • Sr. Member
  • *
  • Posts: 4716
  • Mole Snacks: +469/-72
  • Gender: Male
  • Organic Chemist
    • My research
Re: NMR spectrum problem!
« Reply #3 on: September 14, 2014, 10:39:13 AM »
Assume R is an alkyl group (say, R = CH3 for example) and draw the options as real compounds - any alkanes?
Logged
My research: Google Scholar and Researchgate
Pages: [1]   Go Up
« previous next »
Sponsored Links