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. The chemical shift, specifically the signal for the

trimethylsilyl A trimethylsilyl group (abbreviated TMS) is a functional group in organic chemistry. This group consists of three methyl groups bonded to a silicon atom minus;Si(CH3)3 which is in turn bonded to the rest of a molecule. This structural group i ...

group, is relatively insensitive to pH. 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 In organic chemistry, a carboxylic acid is an organic acid that contains a carboxyl group () attached to an Substituent, R-group. The general formula of a carboxylic acid is often written as or , sometimes as with R referring to an organyl ...

instead of the

sulfonic acid In organic chemistry, sulfonic acid (or sulphonic acid) refers to a member of the class of organosulfur compounds with the general formula , where R is an organic alkyl or aryl group and the group a sulfonyl hydroxide. As a substituent, it is kn ...

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.

References

{{Reflist Sulfonic acids Trimethylsilyl compounds Organic sodium salts Nuclear magnetic resonance