Semiheavy water

Semiheavy water is the result of replacing one of the protium in light water to deuterium.[1] It exists whenever there is water with light hydrogen (protium, ¹H) and deuterium (D or ²H) in the mix. This is because hydrogen atoms (hydrogen-1 and deuterium) are rapidly exchanged between water molecules. Water containing 50% H and 50% D in its hydrogen contains about 50% HDO and 25% each of H₂O and D₂O, in dynamic equilibrium.[2] In regular water, about 1 molecule in 3,200 is HDO (one hydrogen in 6,400 is D). By comparison, heavy water D₂O[3] occurs at a proportion of about 1 molecule in 41 million (i.e., one in 6,400²). This makes semiheavy water far more common than "normal" heavy water.

Semiheavy water

Names
IUPAC name (O-^2H1)Water
Other names Deuterium hydrogen monoxide Deuterium hydrogen oxide, Water-d1 , Water-d
Identifiers
CAS Number	14940-63-7
3D model (JSmol)	Interactive image
ChEBI	CHEBI:33806
ChemSpider	123344
Gmelin Reference	115
PubChem CID	139859
CompTox Dashboard (EPA)	DTXSID50164262
InChI InChI=1S/H2O/h1H2/i/hD Key: XLYOFNOQVPJJNP-DYCDLGHISA-N
SMILES [2H]O
Properties
Chemical formula	H^2HO (also HDO)
Molar mass	19.0214 g mol^−1
Appearance	Very pale blue, transparent liquid, very similar to regular water
Density	1.054 g cm^−3
Melting point	3.81 °C (38.86 °F; 276.96 K)
Boiling point	101.42 °C (214.56 °F; 374.57 K)
Solubility in water	miscible
log P	−0.65
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N verify (what is ^YN ?)
Infobox references

The freezing point of semiheavy water is close to the freezing point of heavy water. (3.8°C)

References

1. Tashakor S (2016-09-28). "Neutronic Investigation of Semi-Heavy Water Application in Hplwr New Flow Pattern". CNL Nuclear Review: 1–5. doi:10.12943/CNR.2016.00019.
2. Goncharuk VV, Kavitskaya AA, Romanyukina IY, Loboda OA (June 2013). "Revealing water's secrets: deuterium depleted water". Chemistry Central Journal. 7 (1): 103. doi:10.1186/1752-153X-7-103. PMC 3703265. PMID 23773696.
3. "Heavy water | chemical compound". Encyclopedia Britannica. Retrieved 2019-04-24.

Further reading

• Schwarzer D, Lindner J, Vöhringer P (October 2005). "Energy relaxation versus spectral diffusion of the OH-stretching vibration of HOD in liquid-to-supercritical deuterated water". The Journal of Chemical Physics. 123 (16): 161105. doi:10.1063/1.2110087. hdl:11858/00-001M-0000-0012-E7B7-2. PMID 16268674.