Accurately and Quickly Interpreting NMR/IR Spectra

Click For Summary

Discussion Overview

The discussion revolves around the interpretation of NMR and IR spectra to confirm the synthesis of n-bromobutane (1-bromobutane). Participants explore the validity of the spectral analysis and the implications of peak shifts in the NMR spectrum.

Discussion Character

  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant interprets the IR spectrum, identifying peaks for CH2 groups and a methyl group, concluding the synthesis of n-bromobutane.
  • The same participant expresses concern about the shifting of ppm values in the NMR spectrum but acknowledges that this may not invalidate their interpretation.
  • Another participant questions the identification of the rightmost small peak as CDCl3 and suggests setting it to 0 for accurate interpretation.
  • A different participant notes that the IR spectrum resembles a reference spectrum for 1-bromobutane, although clarity is an issue.
  • A later reply indicates that the participant who posted the spectra feels more confident after reviewing NMR/IR interpretation, suggesting a positive reception of feedback.

Areas of Agreement / Disagreement

Participants express varying levels of confidence in the spectral interpretations, with some affirming the resemblance of the spectra to known references while others raise questions about specific details. No consensus is reached on the overall validity of the initial interpretation.

Contextual Notes

There are limitations regarding the clarity of the IR spectrum and potential uncertainties in the interpretation of peak shifts in the NMR spectrum. The discussion does not resolve these issues.

Who May Find This Useful

Individuals interested in organic chemistry, particularly those studying spectral analysis techniques in the context of NMR and IR spectroscopy.

biochem850
Messages
51
Reaction score
0
In examining the IR spectrum, I noted that there were peaks for CH2-x where x is bromine, methylene (2 peaks) and a peak corresponding to a methyl group; I concluded that I've synthesized n-bromobutane. Is the method I used to interpret my spectra sound? *CDCl3 was the IR solvent

In addition, in looking at the HNMR spectra, I concluded that the protons shown in the NMR spectra corresponded to the groups determined in the IR spectra. My only concern is that the approximate ppm(s) seem to be shifted yet I know that this may not necessarily mean that my interpretation is wrong. Can someone confirm that my logic is sound and supported?

I've attached the NMR and the IR. http://i42.photobucket.com/albums/e309/Alex_Jsoh/IRSpectrum-page-001_zps084bb818.jpg

http://i42.photobucket.com/albums/e309/Alex_Jsoh/NMRSpectrum-page-001_zpsdd2a7edc.jpg

Thanks!
 
Chemistry news on Phys.org
What is n-bromobutane?
 
I'm sorry, 1-bromobutane (or n-butyl bromide).
 
Is the rightmost small peak CDCL3? Maybe you should set it to 0?
If so then it works well with the 1-bromobutane.
 
Can't really see your IR spectrum very clearly, but it does look similar to the reference IR spectrum for 1-bromobutane.
n-bromobutane.gif
 
Yeah, someone else did the IR/NMR for me.

The smallest peak is CDCl3 and it seems that setting it to 0 is prudent.

I did some thorough review of NMR/IR and I'm pretty confident now!

Thanks guys!
 

Similar threads

IR spectra and point group symmetry
  • · Replies 1 ·
Replies
1
Views
4K
What are the key steps to analyzing an NMR spectrum?
  • · Replies 1 ·
Replies
1
Views
4K