NMR solvent residual peaks
Trace solvents, drying agents, and workup residues often appear as extra signals beside your compound. The tables below list typical ¹H chemical shifts (δ, ppm) reported for common impurities in each deuterated solvent. Values are taken from the Gottlieb (1997) and Fulmer (2010) compilations (DOI 10.1021/jo971176v, 10.1021/om100106e). Shifts drift slightly with temperature, concentration, and water content—compare nearby runs on the same instrument when assigning peaks.
To reduce impurity signals: use fresh solvent, avoid silicone grease near the NMR tube, dry glassware, and remove volatile solvents (EtOAc, DCM, ether, THF) on a rotary evaporator before dissolving the sample. Residual water appears at solvent-dependent chemical shifts; see the water-in-solvents table on the solvent residual peaks page.
Per-solvent impurity peak lists: CDCl₃, DMSO-d₆, D₂O, CD₃OD, Acetone-d₆, CD₃CN, C₆D₆, THF-d₈.
| Solvent | ¹H residual | ¹³C residual | Boiling point | Melting point | Note |
|---|---|---|---|---|---|
| CDCl₃ | 7.26 (s) | 77.16 | 61 °C | −64 °C | Most common organic deuterated solvent |
| DMSO-d₆ | 2.50 (quint) | 39.52 | 189 °C | 18 °C | Common for wet samples |
| D₂O | 4.79 (s) | — | 101 °C | 3.8 °C | Aqueous samples; residual water/HOD overlaps the solvent peak |
| CD₃OD | 3.31 (quint) | 49.00 | 65 °C | −97 °C | MeOH residual peaks are common |
| Acetone-d₆ | 2.05 (quint) | 29.84 / 206.26 | 56 °C | −59 °C | |
| CD₃CN | 1.94 (quint) | 1.32 / 118.26 | 82 °C | −46 °C | |
| THF-d₈ | 1.72 / 3.58 (m) | 25.31 / 67.21 | 66 °C | −108 °C | |
| C₆D₆ | 7.16 (s) | 128.06 | 80 °C | 6 °C | |
| CD₂Cl₂ | 5.32 (s) | 53.84 | 40 °C | −97 °C | |
| Toluene-d₈ | 2.08 / 6.97–7.09 | 20.4 / 125–137 | 110 °C | −90 °C | |
| Pyridine-d₅ | 7.22 / 7.58 / 8.74 | 123.5 / 135.5 / 149.9 | 115 °C | −42 °C | |
| DMF-d₇ | 8.03 / 2.92 / 2.75 | 162.7 / 35.2 / 30.1 | 153 °C | −61 °C |
Water (H₂O / HOD) in deuterated solvents
¹H δ (ppm) for residual water—one of the most searched solvent-impurity questions. Source: Gottlieb / Fulmer tables (see references).
| Solvent | ¹H water peak |
|---|---|
| CDCl₃ | 1.56 |
| DMSO-d₆ | 3.33 |
| D₂O | 4.79 |
| CD₃OD | 4.87 |
| Acetone-d₆ | 2.84 |
| CD₃CN | 2.13 |
| C₆D₆ | 0.40 |
| THF-d₈ | 2.58 |
Also see 1H NMR prediction and per-solvent impurity pages linked below.
How to use this table: locate the solvent residual first (often the tallest sharp singlet near the values above), then compare unknown peaks to the impurity pages for that solvent. For carbon NMR, the solvent triplet or quintet is usually the reference anchor. Temperature changes move hydrogen-bonded peaks (water, alcohols) more than aromatic or alkyl impurities.
Références et sources
- NMRShiftDB2 — open experimental NMR chemical shift database.
- Steinbeck, C.; Kuhn, S. NMRShiftDB — nmrshiftdb.nmr.uni-koeln.de
- Gottlieb, H. E.; Kotlyar, V.; Nudelman, A. NMR Chemical Shifts of Common Laboratory Solvents as Trace Impurities. J. Org. Chem. 1997, 62, 7512–7515.
- Fulmer, G. R. et al. NMR Chemical Shifts of Trace Impurities. Organometallics 2010, 29, 2176–2179.
- PubChem — compound identifiers and structure depictions (NIH/NCBI).
- Related tools: nmrdb.org (community NMR prediction reference).