Help me identify peaks in H NMR please

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SUMMARY

The discussion centers on identifying peaks in a 1H NMR spectrum related to the experiment "Reducing Benzil using Sodium Borohydride." The participant obtained a melting point of 134-136°C, suggesting the presence of benzoin rather than meso-hydrobenzoin. However, thin layer chromatography (TLC) results indicated a near-identical match to meso-hydrobenzoin. The participant is struggling with peak identification in the NMR spectrum, particularly with a significant peak at ~7.2 ppm, which they suspect may indicate impurities.

PREREQUISITES
  • Understanding of 1H NMR spectroscopy
  • Familiarity with thin layer chromatography (TLC)
  • Knowledge of organic compound melting points
  • Basic skills in interpreting NMR spectra
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  • Research techniques for purifying samples prior to NMR analysis
  • Learn about integrating peaks in 1H NMR spectra
  • Study the structural characteristics of meso-hydrobenzoin
  • Explore common impurities in NMR samples and their spectral signatures
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Chemistry students, organic chemists, and laboratory technicians involved in NMR spectroscopy and organic synthesis.

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CHM238L - Identifying Peaks of H NMR spectra

Homework Statement



The experiment is "Reducing Benzil using Sodium Borohydride".
The experiment itself was simple enough and when I finished, I got a melting point of 134-136 C, which is indicative of benzoin (135-137) rather than meso-hydrobenzoin (137-139), however my thin layer chromatography revealed that my sample was nearly identical to meso-hydrobenzoin, and I tend to believe that more so than the melting point. It's possible my sample wasn't pure.

So, I also ran the NMR of my sample and got a spectra for it, but I am having trouble identifying the peaks. Please help me out here!

Here is the picture of the 1H NMR spectra.
http://img246.imageshack.us/img246/5873/95924000.jpg"

Homework Equations


This is a picture of the reaction and the 5 possible products. I circled Meso-Hydrobenzoin, which is what I believe to have after my TLC test.
http://img515.imageshack.us/img515/8025/41232169.jpg"


The Attempt at a Solution


I cleaned the NMR tube a few days in advance. I'm not sure if there is any H2O or Acetone showing in the spectra... I tried integrating the big peak at ~7.2 at 10, and I get way too many hydrogens.
It should have 14 hydrogens only if it is meso-hydrobenzoin.

Thanks in advance!
 
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Is this too difficult for people?
I'm much better at identifying the structures in Carbon 13 NMR, honestly.
I don't like hydrogen NMR.

This is for a lab report for an experiment I did last week that's due tomorrow.
I've got the rest of the lab report done, just need to verify what I have with my NMR.
Help please :p
 

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