My aromatic compound shows only one spot on TLC, but every time when I do the HNMR, I get peaks in the region 0.8 to 2ppm, which do not correlate to any solvent or water present in the solvents. A portion of spectrum with the red arrows pointing at the unwanted peaks is attached here with for clarity. My sample is about 50mg solid. Any suggestions?
Even after grease removal such peaks appears, than you have to pass it with some suitable cinematographic material suitable to your compound e.g. sephadex etc
You may try the following:
Pay attention to the NMR sample tube, because reused NMR sample tube may contain residual solvent, volatile organic matters etc in it. So, use a new or properly cleaned sample tube stored in a vacuum desiccator with proper alignment.
Dry the product long time under reduced pressure with vacuum conditions
You may also try fridge drying.
Aromatic compound shows only one spot on TLC other are impurities of vacuum grease ,/aliphatic ether /water etc. other peaks are observed as impurities proton NMR .
- Badges
- Science topic