Resources
Practical references we use in the lab, from NMR impurity tables and column chromatography to Schlenk line technique and catalysis tests. Open to everyone; 112 links in 17 topics, checked every month.
Analysis
Purification
At the bench
Safety and sustainability
Reference
NMR
Solvent and impurity peaks, shift data, and getting clean, quantitative spectra.
Confirms structure and purity. A clean, dilute sample gives sharp spectra.
Key steps
- 5–10 mg (¹H) or 20–50 mg (¹³C) in 0.6 mL deuterated solvent.
- Filter through cotton if anything is undissolved.
- Reference to residual solvent (CDCl₃: 7.26 / 77.16 ppm).
- Report δ (multiplicity, J in Hz, integration).
Tips
- Check impurity tables for solvent and water peaks first.
- D₂O shake identifies OH and NH protons.
- NMR yield: weighed internal standard, long relaxation delay.
- Paramagnetic Co(II)/Mn(II) complexes give broad, shifted peaks.
Common mistakes
- Too concentrated: poor shimming, broad lines.
- Old, acidic CDCl₃ with acid-sensitive compounds (filter through basic alumina).
Further reading
- NMR shifts of trace impurities in organometallic solvents (Fulmer 2010)paper
- NMR shifts of trace impurities, industrial solvents (Babij 2016)paper
- NMR shifts of common lab solvents as trace impurities (Gottlieb 1997)paper
- Hans Reich NMR collection (1H, 13C, 19F, 31P, coupling constants)organicchemistrydata.org
- How to take a good 1H NMR spectrumchem.rochester.edu
- Troubleshooting 1H NMR spectrachem.rochester.edu
- Quantitative 1H NMR and purity (Pauli 2014)paper
- Paper
- Database or tool
- Book
- Guide