NMR chemical shifts of Commom Impurities

NMR chemical shifts of solvents, buffers, salts and other small molecules commonly used in the laboratory during synthesis and purification processes.

The database is a collection of NMR chemical shift from small molecules. The database can be used to identify unknown signals within a mixture of different compounds belonging to impurities or small contaminations. The database can also be used for finding signals beloning to specific compounds in preparation to experiments or confirmation of chemical shift belonging to a known compound.

If you are new to the tool, read the instructions.
Enter number (Ex. 3.71)
Enter number (Ex. 0.1)

How to use the database.

The database lets you choose between 2 different types of NMR signals. 1H-NMR and 13C-NMR which can be choosen in the first dropdown menu named NMR-type. The second menu lets you choose which deuturated solvent was used for the experiments. This can be choosen in the second dropdown menu named solvent. The third menu named chemical shift, lets you put in a number of a chemical shift you are searching for. The fourth menu puts a restiction on the serach of how far away it will look for a chemical shift to match with called tolerance. If no tolerance is put in it will automatically be put to 0.1 for 1H-NMR and 1.0 for 13C-NMR. The fifth menu multiplicity is optional which set a restiction more on the search. This will only look for the chemical shift with this specific pattern to match the search. Then submit the search.

After submitting the search a list of matchses will appear below the searchbar. To the right the name of the molecule will appear. Next the chemical shift which matched the search will be displayed along with a list of other chemical shifts belonging to this specific molecule. Beside the chemical shift is a letter which displayes which type of multiplicity the chemical shift has. If this assignment of letters to multiplicity is unknown look below for an explanation. Last the atom which the chemical shift belongs to is displayed in bold with a small bit of the chemical formula. Under tolerance of search is a number which displayes how far away the match is the the search. To make the identification easier the chemical structure is depicted to the right. The matched molecules are ordered after closest match with the closest first.

Technical information

The spectra was recorded at a bruker 500 MHz spectrometer equipped with a SampleJet to automatic handle the many samples. The 1H-NMR was recorded at 298o K with no decoupling to carbon or fluor was used during acquisition. The 13C-NMR was recorded at 298o K with decoupling to proton while recording the FID.

Solvents (all solvents are deuterated).

d2o = water; cdcl3 = chloroform; cd2cl2 = dichloromethane; (cd3)2so = dimethylsulfoxide (DMSO); (cd3)2co = acetone; cd3cn = acetonitrile; cd3od = methanol; tfe = trifluoroethane; thf = tetrahydrofurane; c6d6 = benzene; c6d5cl = chlorobenzene.


s = singlet; d = doublet; t = triplet; q = quartet; qu = quintet; sex = sextet; sep = septet; o = octet; n = nonet; dd = double doublet; dt = double triplet; dq = double quartet; ddd = double double doublet; ddt = double double triplet; dddd = double double double doublet; tt = tripple triplet; m = multiplet; bs = broad signal.

If you wish to add some compounds to the database please contact us by mail. (larsalf1@gmail.com or fmulder@chem.au.dk)

Webpage made by Lars Alf Jensen and Frans Mulder