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 standand for proton NMR spectroscopy of aqueous solutions.[1] The chemical shift, specifically the signal for the trimethylsilyl group, is relatively insensitive to pH.[2]
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Systematic IUPAC name
3-(Trimethylsilyl)propane-1-sulfonate, sodium salt | |
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3D model (JSmol) |
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Abbreviations | DSS |
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CompTox Dashboard (EPA) |
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Properties | |
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]
References
- Harris, Robin K.; Becker, Edwin D.; Cabral De Menezes, Sonia M.; Granger, Pierre; Hoffman, Roy E.; Zilm, Kurt W. (2008). "Further Conventions for NMR Shielding and Chemical Shifts (IUPAC Recommendations 2008)". Pure and Applied Chemistry. 80 (2): 59–84. Bibcode:2008JMagR.191..340.. doi:10.1351/pac200880010059.
- De Marco, Antonio (1977). "pH Dependence of Internal References". Journal of Magnetic Resonance. 26 (3): 527–528. Bibcode:1977JMagR..26..527D. doi:10.1016/0022-2364(77)90104-4.
- Nowick, James S.; Khakshoor, Omid; Hashemzadeh, Mehrnoosh; Brower, Justin O. (2003). "DSA: A New Internal Standard for NMR Studies in Aqueous Solution". Org. Lett. 5 (19): 3511–3513. doi:10.1021/ol035347w. PMID 12967312.