DSS (NMR standard)

Sodium trimethylsilylpropanesulfonate (DSS) is the organosilicon compound with the formula (CH₃)₃SiCH₂CH₂CH₂SO₃⁻Na⁺. It is the sodium salt of trimethylsilylpropanesulfonic acid. A white, water-soluble solid, it is used as a chemical shift standard for proton NMR spectroscopy of aqueous solutions.^[1] The chemical shift, specifically the signal for the trimethylsilyl group, is relatively insensitive to pH.^[2]

DSS (NMR standard)

Names
Preferred IUPAC name Sodium 3-(trimethylsilyl)propane-1-sulfonate
Other names 3-trimethylsilyl-1-propanesulfonate, sodium salt; 2,2-Dimethyl-2-silapentane-5-sulfonate sodium salt; DSS sodium salt(trimethylsilyl)-1-propanesulfonate
Identifiers
CAS Number	2039-96-5 Y
3D model (JSmol)	Interactive image
Abbreviations	DSS
ChemSpider	67436 Y
EC Number	218-031-5
PubChem CID	5167273
CompTox Dashboard (EPA)	DTXSID7062118
InChI InChI=1S/C6H16O3SSi.Na/c1-11(2,3)6-4-5-10(7,8)9;/h4-6H2,1-3H3,(H,7,8,9);/q;+1/p-1 Key: HWEXKRHYVOGVDA-UHFFFAOYSA-M
SMILES C[Si](C)(C)CCCS(=O)(=O)[O-].[Na+]
Properties
Chemical formula	C6H15NaO3SSi
Molar mass	218.32 g·mol−1
Appearance	White solid
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

The proton spectrum of DSS also exhibits resonances at 2.91 ppm (m), 1.75 ppm (m), and 0.63 ppm (m) at an intensity of 22% of the reference resonance at 0 ppm.

Alternatives

Sodium trimethylsilyl propionate (TSP) is a related compound used as an NMR standard. It uses a carboxylic acid instead of the sulfonic acid found in DSS to confer water solubility. As a weak acid, TSP is more sensitive to changes in pH.

4,4-Dimethyl-4-silapentane-1-ammonium trifluoroacetate (DSA) has also been proposed as an alternative, to overcome certain drawbacks of DSS.^[3]