A Guide to NMR Reference Compounds

© 2005, Blue Water Ventures

This table lists the chemical shifts of reference compounds commonly used in NMR spectroscopy.

Compound Nucleus Solvent Chemical

Reference Compounds for Proton Spectra

Acetonitrile 1H CDCl3 2.05
1,4-Dioxane 1H CDCl3 3.69
1H D2O 3.75
DSS - 2,2-Dimethyl-2-silapentane-5-sulfonate 1H D2O 0.000 (def)
Sodium Acetate 1H D2O 1.90
TMS - Tetramethylsilane 1H Organic 0.000 (def)

Reference Compounds for 2H Spectra

Chloroform-d1 2H Organic 7.25

Reference Compounds for 11B Spectra

Boric Acid 11B Aqueous 36
Trimethyl Borate 11B Organic 0.000 (def)
Triphenylborane 11B Organic -43

Reference Compounds for 13C Spectra

Chloroform-d 13C Organic 77.0 (3)
1,4-Dioxane 13C CDCl3 67.65
Tetramethylammonium Bromide 13C D2O 56.14 (3)4
TMS - Tetramethylsilane 13C Organic 0.000 (def)

Reference Compounds for 15N Spectra

Ammonia (Liquid) 15N Neat 0.000 (def)
Ammonium Bromide 15N Aqueous 27.3
1,4-Morpholine 15N Aqueous 32.1
Nitromethane2 15N Organic 380.2
Pyridine 15N Organic 317
Sodium Nitrate 15N Aqueous 376.5
Tetramethylammonium Bromide 15N Aqueous 43.5

Reference Compounds for 19F Spectra

Fluorobenzene 19F Organic -113.15
Trichlorofluoromethane3 19F Organic 0.000 (def)
1,1,2-Trichlorotrifluoroethane3 19F Organic -71.75 (t)
Trifluoroacetic Acid 19F Organic -76.55
α,α,α-Trifluorotoluene 19F Organic -63.72

Reference Compounds for 29Si Spectra

TMS - Tetramethylsilane 29Si Organic 1 0.000 (def)

Reference Compounds for 31P Spectra

Phosphoric Acid H3PO4 31P Aqueous 0.000 (def)
Phosphorus P4 31P Organic 461
Trimethyl Phosphate (CH3O)3PO 31P Aqueous 0.000
Triphenylphosphine P(C6H5)3 31P Organic -6
Triphenylphosphine Oxide O=P(C6H5)3 31P Organic 23.0

1 Proton Decoupled.
2 Nitromethane is often used as an external reference (in capillary), and given a chemical shift value of zero.
3 The presence of 35Cl and 37Cl causes the fluorine signal to be split into isotopomeres. This effect amounts to approximately 0.008 ppm for 1,1,2-trichloro-trifluoroethane in CDCl3 at 25°C. References are for the more abundant 35Cl isomer.
4 Splitting by 14N can sometimes be seen. The coupling constant JC,N is approximately 0.17 Hz.