| Boiling Point | 101.4 °C (lit.) |
| Melting Point | 3.8 °C (lit.) |
| Density | 1.1050 g/mL |
| Specific Gravity Approx | 1.105 |
| Flash Point | Not applicable |
| Color | Colorless |
| Linear Formula | D2O |
| Formula Weight | 20.02 |
| Physical Form | Liquid |
| Chemical Name or Material | Deuterium oxide, 99.8 atom % D |
| Molecular Weight | 20.02 g/mol |
| SMILES String | [2H]O[2H] |
| Grade | NMR |
| Merck Index | 15, 2942 |
| Solubility Information | Solubility in water: miscible, exothermic reaction. |
| Refractive Index | 1.328 |
| Assay | 99.75% min (existing Sarchem spec — Sigma's own listing states 99.9 atom% D for their own SKU, a different product; not substituted in, see note) |
| Viscosity | 1.25 mPa.s (20°C) |
| Deuterium (D) | 99.75% min. |
| CAS Number | 7789-20-0 (corrected — see flag above) |
| Storage Temperature | Room temperature |
| Storage Class | 12 – Non-Combustible Liquids |
| EC Number | 232-148-9 |
| NACRES | NA.21 |
| PubChem Substance ID | 24849176 |
| UNSPSC Code | 12142201 |
| MDL Number | MFCD00044636 |
| Quality Segment | 200 |
| InChI | 1S/H2O/h1H2/i/hD2 |
| InChI Key | XLYOFNOQVPJJNP-ZSJDYOACSA-N |
| 24602 |
Deuterium oxide is the deuterated analog of water, built from two deuterium atoms and one oxygen atom in place of ordinary hydrogen. Deuterium carries an extra neutron compared to protium, and that added mass changes how the molecule vibrates and how strongly it participates in hydrogen bonding, which shifts its physical constants — a higher boiling point, higher melting point, and greater density than ordinary water. Because the deuterium nucleus behaves very differently from a proton under an NMR magnetic field, D2O contributes essentially no interfering signal in standard proton NMR spectra.
Sarchem Labs’ Deuterium Oxide is manufactured and packaged as an NMR-grade liquid, intended for laboratories that need dependable isotopic purity lot after lot.
The dominant use is as the solvent of choice for solution-state NMR, where its lack of a competing proton signal lets chemists observe analyte and internal standard peaks cleanly. Beyond spectroscopy, it serves as a dissolution medium for certain metal complexes and as a mechanistic tool for tracking hydrogen positions and exchange pathways.
D2O is also a practical synthetic building block, used to generate other deuterated reagents such as trifluoroacetic acid-d, and functions as the deuterium source in catalytic H/D exchange reactions that label alcohols or convert alkynes into deuterated alkenes.
No GHS pictograms, signal word, or hazard/precautionary statements were assigned to this material in the reference data reviewed — deuterium oxide has a low apparent hazard profile, consistent with it being chemically water in an isotopically substituted form. That said, “no GHS classification listed” is not the same as “no precautions required”:
