Chemical Forums

Please login or register.

Login with username, password and session length

Sponsored links

Pages: [1]   Go Down

Author Topic: Reasons for amorphous peak in NMR?  (Read 433 times)

0 Members and 1 Guest are viewing this topic.

Misa

  • New Member
  • **
  • Mole Snacks: +0/-0
  • Offline Offline
  • Posts: 5
Reasons for amorphous peak in NMR?
« on: October 09, 2016, 02:37:08 AM »

I have been working with compounds derived from 1,10-Phenanthroline. For products with different functional groups, solvents and reaction conditions, I am seeing an amorphous peak for the protons meta to the nitrogens instead of the expected dd.

What could be reasons for this distortion?

The compounds are known to π stack and I was wondering if that could be a factor?

Any ideas would be greatly appreciated !!  :D :D
Logged

TheUnassuming

  • Chemist
  • Full Member
  • *
  • Mole Snacks: +39/-1
  • Offline Offline
  • Posts: 422
Re: Reasons for amorphous peak in NMR?
« Reply #1 on: October 10, 2016, 02:59:56 AM »

Are the other peaks in your spectra clean?  When you search the literature for similarly substituted compounds, do the spectra reported also show this muddy meta proton?
Logged
When in doubt, avoid the Stille coupling.

Babcock_Hall

  • Chemist
  • Sr. Member
  • *
  • Mole Snacks: +167/-11
  • Offline Offline
  • Posts: 2697
Re: Reasons for amorphous peak in NMR?
« Reply #2 on: October 10, 2016, 11:34:25 AM »

One might consider the possibility of a paramagnetic impurity.  However, the hydrogen atoms closest to the paramagnetic center should show the greatest broadening, all else held equal.
Logged

Irlanur

  • Chemist
  • Full Member
  • *
  • Mole Snacks: +21/-4
  • Offline Offline
  • Posts: 365
Re: Reasons for amorphous peak in NMR?
« Reply #3 on: October 18, 2016, 10:55:18 PM »

can you post the spectrum/peak?
Logged
Pages: [1]   Go Up
 

Mitch Andre Garcia's Chemical Forums 2003-Present.

Page created in 0.078 seconds with 24 queries.