DEUTERIUM OXIDE

CAS NUMBER: 7789-20-0

EC NUMBER: 232-148-9

MOLECULAR FORMULA: D2O (H2O)

MOLECULAR WEIGHT: 20.028

IUPAC NAME: deuterated water

Deuterium Oxide (Heavy Water, 2H2O, D2O) is a form of water that contains only deuterium (2H or D, also known as heavy hydrogen) rather than the common hydrogen-1 isotope (1H or H, also called protium) that makes up most of the hydrogen in normal water.
The presence of the heavier hydrogen isotope gives the water different nuclear properties, and the increase of mass gives it slightly different physical and chemical properties when compared to normal water.
Deuterium Oxide is a deuterated compound and a water

Deuterium Oxide is a stable, non-radioactive isotopic form of water, containing 2 atoms of deuterium (D) and one atom of oxygen (2D2O), with DNA-labeling activity. 
Upon ingestion of deuterium oxide, 2H is incorporated into the deoxyribose moiety of DNA of newly divided cells. 
Rapidly dividing cells, as in the case of B-cell chronic lymphocytic leukemia (B-CLL), can be labeled with deuterium oxide and measured using gas chromatography and/or mass spectrometry.

Explanation:
Deuterium is a hydrogen isotope with a nucleus containing a neutron and a proton; the nucleus of a protium (normal hydrogen) atom consists of just a proton. 
The additional neutron makes a deuterium atom roughly twice as heavy as a protium atom.
A molecule of Deuterium Oxide has two deuterium atoms in place of the two protium atoms of ordinary "light" water. 

Actually, the term Deuterium Oxide as defined by the IUPAC Gold Book can also refer to water in which a higher than usual proportion of hydrogen atoms are deuterium rather than protium. 
For comparison, ordinary water (the "ordinary water" used for a deuterium standard) contains only about 156 deuterium atoms per million hydrogen atoms, meaning that 0.0156% of the hydrogen atoms are of the heavy type. 
Thus Deuterium Oxide as defined by the Gold Book includes hydrogen-deuterium oxide (HDO) and other mixtures of D2O, H2O, and HDO in which the proportion of deuterium is greater than usual. 
For instance, the Deuterium Oxide used in CANDU reactors is a highly enriched water mixture that contains mostly deuterium oxide D2O, but also some hydrogen-deuterium oxide (HDO) and a smaller amount of ordinary hydrogen oxide H2O. 

Deuterium Oxide is 99.75% enriched by hydrogen atom-fraction—meaning that 99.75% of the hydrogen atoms are of the heavy type; however, Deuterium Oxide in the Gold Book sense need not be so highly enriched. 
Where this article uses Deuterium Oxide, though, it means D2O. 
The weight of a Deuterium Oxide molecule, however, is not substantially different from that of a normal water molecule, because about 89% of the molecular weight of water comes from the single oxygen atom rather than the two hydrogen atoms.

Deuterium Oxide is not radioactive. 
In Deuterium Oxide's pure form, it has a density about 11% greater than water, but is otherwise physically and chemically similar. 
Nevertheless, the various differences in deuterium-containing water (especially affecting the biological properties) are larger than in any other commonly occurring isotope-substituted compound because deuterium is unique among heavy stable isotopes in being twice as heavy as the lightest isotope. 

This difference increases the strength of water's hydrogen-oxygen bonds, and this in turn is enough to cause differences that are important to some biochemical reactions. 
The human body naturally contains deuterium equivalent to about five grams of Deuterium Oxide, which is harmless. 
When a large fraction of water (> 50%) in higher organisms is replaced by Deuterium Oxide, the result is cell dysfunction and death.

Deuterium Oxide was first produced in 1932, a few months after the discovery of deuterium.
With the discovery of nuclear fission in late 1938, and the need for a neutron moderator that captured few neutrons, Deuterium Oxide became a component of early nuclear energy research. 
Since then, Deuterium Oxide has been an essential component in some types of reactors, both those that generate power and those designed to produce isotopes for nuclear weapons. 

These Deuterium Oxide reactors have the advantage of being able to run on natural uranium without using graphite moderators that pose radiological and dust explosion hazards in the decommissioning phase. 
The graphite moderated Soviet RBMK design tried to avoid using either enriched uranium or Deuterium Oxide (being cooled with ordinary "light" water instead) which produced the positive void coefficient that was one of a series of flaws in reactor design leading to the Chernobyl disaster. 
Most modern reactors use enriched uranium with ordinary water as the moderator.

Physical Properties:
The physical properties of water and Deuterium Oxide differ in several respects. 
Deuterium Oxide is less dissociated than light water at given temperature, and the true concentration of D+ ions is less than  H+ ions would be for a light water sample at the same temperature. 
The same is true of OD− vs.  OH− ions. 
For Deuterium Oxide Kw D2O (25.0 °C) = 1.35 × 10−15, and [D+ ] must equal [OD− ] for neutral water. 
Thus pKw D2O = p[OD−] + p[D+] = 7.44 + 7.44 = 14.87 (25.0 °C), and the p[D+] of neutral Deuterium Oxide at 25.0 °C is 7.44.

The pD of Deuterium Oxide is generally measured using pH electrodes giving a pH (apparent) value, or pHa, and at various temperatures a true acidic pD can be estimated from the directly pH meter measured pHa, such that pD+ = pHa (apparent reading from pH meter) + 0.41. 
The electrode correction for alkaline conditions is 0.456 for Deuterium Oxide. 
The alkaline correction is then pD+ = pHa(apparent reading from pH meter) + 0.456. 
These corrections are slightly different from the differences in p[D+] and p[OD-] of 0.44 from the corresponding ones in Deuterium Oxide.

Deuterium Oxide is 10.6% denser than ordinary water, and Deuterium Oxide's physically different properties can be seen without equipment if a frozen sample is dropped into normal water, as it will sink. 
If the water is ice-cold the higher melting temperature of heavy ice can also be observed: it melts at 3.7 °C, and thus does not melt in ice-cold normal water.

An early experiment reported not the "slightest difference" in taste between ordinary and Deuterium Oxide.
One study has concluded that Deuterium Oxide tastes "distinctly sweeter" for humans, and is mediated by the TAS1R2/TAS1R3 taste receptor.
Rats given a choice between distilled normal water and Deuterium Oxide were able to avoid the Deuterium Oxide based on smell, and it may have a different taste.
Some people report that minerals in water affect taste, e.g. potassium lending a sweet taste to hard water, but there are many factors of a perceived taste in water besides mineral contents.

Deuterium Oxide lacks the characteristic blue color of light water; this is because the molecular vibration harmonics, which in light water cause weak absorption in the red part of the visible spectrum, are shifted into the infrared and thus Deuterium Oxide does not absorb red light.
No physical properties are listed for "pure" semi-Deuterium Oxide, because it is unstable as a bulk liquid. 
In the liquid state, a few water molecules are always in an ionised state, which means the hydrogen atoms can exchange among different oxygen atoms. 

Semi-Deuterium Oxide could, in theory, be created via a chemical method[further explanation needed], but it would rapidly transform into a dynamic mixture of 25% light water, 25% Deuterium Oxide, and 50% semi-Deuterium Oxide. 
However, if it were made in the gas phase and directly deposited into a solid, semi-Deuterium Oxide in the form of ice could be stable. 
This is due to collisions between water vapor molecules being almost completely negligible in the gas phase at standard temperatures, and once crystallized, collisions between the molecules cease altogether due to the rigid lattice structure of solid ice

Production:
On Earth, deuterated water, HDO, occurs naturally in normal water at a proportion of about 1 molecule in 3,200. 
This means that 1 in 6,400 hydrogen atoms is deuterium, which is 1 part in 3,200 by weight (hydrogen weight). 
The HDO may be separated from normal water by distillation or electrolysis and also by various chemical exchange processes, all of which exploit a kinetic isotope effect. 
With the partial enrichment also occurring in natural bodies of water under particular evaporation conditions.
(For more information about the isotopic distribution of deuterium in water, see Vienna Standard Mean Ocean Water.) In theory, deuterium for Deuterium Oxide could be created in a nuclear reactor, but separation from ordinary water is the cheapest bulk production process.

The difference in mass between the two hydrogen isotopes translates into a difference in the zero-point energy and thus into a slight difference in the speed of the reaction. 
Once HDO becomes a significant fraction of the water, Deuterium Oxide becomes more prevalent as water molecules trade hydrogen atoms very frequently. 
Production of pure Deuterium Oxide by distillation or electrolysis requires a large cascade of stills or electrolysis chambers and consumes large amounts of power, so the chemical methods are generally preferred.

The most cost-effective process for producing Deuterium Oxide is the dual temperature exchange sulfide process (known as the Girdler sulfide process) developed in parallel by Karl-Hermann Geib and Jerome S. Spevack in 1943.
An alternative process, patented by Graham M. Keyser, uses lasers to selectively dissociate deuterated hydrofluorocarbons to form deuterium fluoride, which can then be separated by physical means. 
Although the energy consumption for this process is much less than for the Girdler sulfide process, this method is currently uneconomical due to the expense of procuring the necessary hydrofluorocarbons.

APPLICATIONS
Nuclear magnetic resonance:
Deuterium Oxide is used in nuclear magnetic resonance spectroscopy when using water as solvent if the nuclide of interest is hydrogen. 
This is because the signal from light-water (1H2O) solvent molecules interferes with the signal from the molecule of interest dissolved in it. 
Deuterium has a different magnetic moment and therefore does not contribute to the 1H-NMR signal at the hydrogen-1 resonance frequency.

For some experiments, it may be desirable to identify the labile hydrogens on a compound, that is hydrogens that can easily exchange away as H+ ions on some positions in a molecule. 
With addition of D2O, sometimes referred to as a D2O shake, labile hydrogens exchange away and are substituted by deuterium (2H) atoms. 
These positions in the molecule then do not appear in the 1H-NMR spectrum.

As noted, modern commercial Deuterium Oxide is almost universally referred to, and sold as, deuterium oxide. 
Deuterium Oxide is most often sold in various grades of purity, from 98% enrichment to 99.75–99.98% deuterium enrichment (nuclear reactor grade) and occasionally even higher isotopic purity.

Organic chemistry:
Deuterium oxide is often used as the source of deuterium for preparing specifically labelled isotopologues of organic compounds. 
For example, C-H bonds adjacent to ketonic carbonyl groups can be replaced by C-D bonds, using acid or base catalysis. 
Trimethylsulfoxonium iodide, made from dimethyl sulfoxide and methyl iodide can be recrystallized from deuterium oxide, and then dissociated to regenerate methyl iodide and dimethyl sulfoxide, both deuterium labelled. 
In cases where specific double labelling by deuterium and tritium is contemplated, the researcher must be aware that deuterium oxide, depending upon age and origin, can contain some tritium.

Infrared spectroscopy:
Deuterium Oxide is often used instead of water when collecting FTIR spectra of proteins in solution. 
H2O creates a strong band that overlaps with the amide I region of proteins. 
The band from D2O is shifted away from the amide I region.

Neutron moderator:
Deuterium Oxide is used in certain types of nuclear reactors, where it acts as a neutron moderator to slow down neutrons so that they are more likely to react with the fissile uranium-235 than with uranium-238, which captures neutrons without fissioning. 
The CANDU reactor uses this design. Light water also acts as a moderator, but because light water absorbs more neutrons than Deuterium Oxide, reactors using light water for a reactor moderator must use enriched uranium rather than natural uranium, otherwise criticality is impossible. 
A significant fraction of outdated power reactors, such as the RBMK reactors in the USSR, were constructed using normal water for cooling but graphite as a moderator. However, the danger of graphite in power reactors (graphite fires in part led to the Chernobyl disaster) has led to the discontinuation of graphite in standard reactor designs.

Because they do not require uranium enrichment, Deuterium Oxide reactors are more of a concern in regards to nuclear proliferation. 
The breeding and extraction of plutonium can be a relatively rapid and cheap route to building a nuclear weapon, as chemical separation of plutonium from fuel is easier than isotopic separation of U-235 from natural uranium. 
Among current and past nuclear weapons states, Israel, India, and North Korea first used plutonium from Deuterium Oxide moderated reactors burning natural uranium, while China, South Africa and Pakistan first built weapons using highly enriched uranium.

In the U.S., however, the first experimental atomic reactor (1942), as well as the Manhattan Project Hanford production reactors that produced the plutonium for the Trinity test and Fat Man bombs, all used pure carbon (graphite) neutron moderators combined with normal water cooling pipes. 
They functioned with neither enriched uranium nor Deuterium Oxide. 
Russian and British plutonium production also used graphite-moderated reactors.

There is no evidence that civilian Deuterium Oxide power reactors—such as the CANDU or Atucha designs—have been used to produce military fissile materials. 
In nations that do not already possess nuclear weapons, nuclear material at these facilities is under IAEA safeguards to discourage any diversion.

Due to its potential for use in nuclear weapons programs, the possession or import/export of large industrial quantities of Deuterium Oxide are subject to government control in several countries. 
Suppliers of Deuterium Oxide and Deuterium Oxide production technology typically apply IAEA (International Atomic Energy Agency) administered safeguards and material accounting to Deuterium Oxide. 
(In Australia, the Nuclear Non-Proliferation (Safeguards) Act 1987.) In the U.S. and Canada, non-industrial quantities of Deuterium Oxide (i.e., in the gram to kg range) are routinely available without special license through chemical supply dealers and commercial companies such as the world's former major producer Ontario Hydro.

Neutrino detector:
The Sudbury Neutrino Observatory (SNO) in Sudbury, Ontario uses 1,000 tonnes of Deuterium Oxide on loan from Atomic Energy of Canada Limited. 
The neutrino detector is 6,800 feet (2,100 m) underground in a mine, to shield it from muons produced by cosmic rays. 
SNO was built to answer the question of whether or not electron-type neutrinos produced by fusion in the Sun (the only type the Sun should be producing directly, according to theory) might be able to turn into other types of neutrinos on the way to Earth. 
SNO detects the Cherenkov radiation in the water from high-energy electrons produced from electron-type neutrinos as they undergo charged current (CC) interactions with neutrons in deuterium, turning them into protons and electrons (however, only the electrons are fast enough to produce Cherenkov radiation for detection).

SNO also detects neutrino electron scattering (ES) events, where the neutrino transfers energy to the electron, which then proceeds to generate Cherenkov radiation distinguishable from that produced by CC events. 
The first of these two reactions is produced only by electron-type neutrinos, while the second can be caused by all of the neutrino flavors. 
The use of deuterium is critical to the SNO function, because all three "flavours" (types) of neutrinos may be detected in a third type of reaction as well, neutrino-disintegration, in which a neutrino of any type (electron, muon, or tau) scatters from a deuterium nucleus (deuteron), transferring enough energy to break up the loosely bound deuteron into a free neutron and proton via a neutral current (NC) interaction.

This event is detected when the free neutron is absorbed by 35Cl− present from NaCl deliberately dissolved in the Deuterium Oxide, causing emission of characteristic capture gamma rays. 
Thus, in this experiment, Deuterium Oxide not only provides the transparent medium necessary to produce and visualize Cherenkov radiation, but it also provides deuterium to detect exotic mu type (μ) and tau (τ) neutrinos, as well as a non-absorbent moderator medium to preserve free neutrons from this reaction, until they can be absorbed by an easily detected neutron-activated isotope.

Deuterium oxide (D2O), aka “heavy water”, is the form of water that contains two atoms of the 2H, or D, isotope. 
The term Deuterium Oxide is also used for water in which 2H atoms replace only some of the 1H atoms. 
In this case, rapid exchange between the two isotopes forms twice as many “semiheavy” HDO molecules as D2O.

For decades, D2O has been extremely useful in many chemical applications. 
The difference between a reaction rate in D2O solvent versus that in H2O often provides clues as to the reaction’s mechanism. 
This is especially important if water is one of the reactants.

In some nuclear reactors, D2O is used to slow down neutrons so that they react with fissionable 235U rather than nonfissioning 238U, thus eliminating the need for uranium enrichment. 
Deuterium Oxide is superior to H2O for this use because of its ≈6 times greater thermal neutron capture cross section.

Deuterium oxide, a deuterated solvent, is a standard prurity solvent for NMR (Nuclear Magnetic Resonance) analyses. 
Various thermodynamic properties (such as intermolecular vibrational frequencies, energy of the hydrogen bond, free energy, enthalpy and entropy) of liquid deuterium oxide have been evaluated. 
Ionization constant for D2O (in the range of 5-50°C), pK values (at 25°C) and enthalpy, entropy, heat capacity change (for the dissociation of D2O) have been reported

Application
Deuterium oxide may be used:
-To prepare trifluoroacetic acid-d by reacting with trifluoroacetic anhydride.
-As a deuteration agent for primary and secondary alcohols at the β-carbon position via H/D exchange reaction in the presence of ruthenium catalyst.
-Along with hexamethyldisilane as a deuterium transfer reagent for alkynes to form (E)-1,2-dideuterioalkenes in the presence of a palladium complex.

Deuterium oxide (Heavy water, Water-d2, D2O) has been used as solvent for the dissolution of internal standard and sample during quantification experiments by NMR. 
Deuterium Oxide has been used for the dissolution of tris(2,2′-bipyridyl)dichlororuthenium(II) hexahydrate Ru(bpy)3.

Deuterium oxide, also known as “heavy water” or “deuterium water”, is the compound of oxygen and the heavy isotope of hydrogen, namely deuterium. 
Deuterium Oxide is called heavy water because its density is greater than H₂O and its chemical formula is D₂O.  
Deuterium contains a neutron and proton in its nucleus, which makes it twice as heavy as protium (hydrogen), which contains only one proton.  
Deuterium oxide is colorless and odorless liquid in normal temperature and pressure.  
Compared to ordinary water, its chemical characteristic is relatively inactive with specific gravity of 1.10775 (25 ℃), melting/freezing point of 3.82 ℃, and boiling point of 101.42 ℃. 
The hydrogen bond strength and degree of association between Deuterium Oxide molecules are both stronger than that of ordinary water molecules.  
The amount of D₂O produced by 1991 was about 30,000 tons1. 
On Earth concentration of D₂O in H₂O is 150-200 ppm. 
Deuterium Oxide has been hypothesized that D₂O is much more abundant in the ice of the Martian polar caps

Pure Deuterium Oxide, D₂O, is the oxide of the heavy stable isotope of hydrogen, deuterium, denoted by the symbols 2H or D. 
Physically and chemically it is almost identical to ordinary “light” water, H₂O, however, its density is 10% higher. 
Deuterium Oxide is this higher density which gives the compound its nickname, “heavy water.”

Electronics industries application of D2O:
Optical Light Emitting Diode (OLEDs)
The hydrogen/deuterium primary kinetic isotope effect provides useful information about the degradation mechanism of OLED materials. Thus, replacement of labile C–H bonds in the OLED with C–D bonds increases the device lifetime by a factor of five without loss of efficiency13.

Optical Fibers
In optical fibers deuterium extracted from D2O and deposited to Si reduces the absorption losses by shifting them to the 1620 nm wavelength, which outside of normal operating range, thus enhancing the optic fiber service life and efficiency several fold16.

Other applications
Deuterium oxide is routinely used in the process of heavy water electrolysis for production of deuterium gas that is essential for semiconductor industries. 
For example, replacing hydrogen with deuterium greatly reduces hot electron degradation effects in metal oxide semiconductor transistors due to isotope kinetic effect. 
Transistor lifetime improvements by factors of 10-50 were reported17.  
Deuterium oxide is also used as non radioactive tracer in hydrology, ecology, entomology, mining industry and other instances when tracing studies are essential but use of radioactive isotopes is not applicable18–20.

Conclusion
In contemporary research D2O provides opportunities to create a more holistic picture of in-vivo metabolic phenotypes, providing a unique platform for development in clinical applications, and the emerging field of personalized medicine9. 
Deuterium Oxide can maintain the stability of vaccines, including the polio vaccine, for long periods without refrigeration21.  
In high technology and electronics industry deuterium oxide enhances the lifespan and performance of OLEDs and increases the service life and efficiency of optic fibers.
Deuterium oxide is used in nuclear magnetic resonance spectroscopy (NMR).

Deuterium oxide, also known as “heavy water” or “deuterium water”, is a molecule composed of two atoms of Deuterium and one atom of Oxygen. 
Deuterium Oxide is called heavy water because its density is greater than H₂O, and its chemical formula is D₂O.
Deuterium oxide is used in pharmacology where H/D substitution increases the half-life of the pharmaceutical agent often favourably affecting the pharmacokinetics of the drug.

Deuterium oxide is routinely used in the process of heavy water electrolysis for the production of deuterium gas that is essential for semiconductor industries. 
For example, replacing hydrogen with deuterium greatly reduces hot-electron degradation effects in metal oxide semiconductor transistors due to the isotope kinetic effect. 

Deuterium Oxide, also called "heavy water", has the chemical formula D2O. 
The deuterium atom, expressed by the symbol D, is a hydrogen isotope. 
The difference between D2O and "regular" water H2O lies in the core of the hydrogen atom: hydrogen 1H, also called protium, has only one proton, whereas deuterium D, also written as 2H, has a proton and a neutron in its nucleus. 
The additional neutron makes the D2O molecule, when compared to water H2O, heavier. 
The hydrogen isotope tritium 3H even has a second neutron in its core.

The molar mass of D2O is 20.0276 g/mol. 
Deuterium Oxides density is higher than the density of H2O. 
Deuterium Oxide is used in Nuclear Magnetic Resonance (NMR) spectroscopy, in organic chemistry, Fourier Transform Infrared (FTIR) spectroscopy, and in some types of nuclear reactors as a moderator to slow down the velocity of neutrons.

Deuterium’s natural abundance is 0.015 per cent. 
In other words, water contains 150 ppm of deuterium. 
For the production of Deuterium Oxide, the concentration of deuterium can be augmented by means of distillation, electrolysis or by means of the so-called Girdler sulfide process, an isotopic exchange process of hydrogen atoms between H2S and H2O over several temperature steps. 
The exchange of deuterium depends on the temperature. 

High temperatures enhance the migration to H2S, low temperatures preferably to H2O. 
Deuterium enriched water with a deuterium content of above 99 % can be produced. 
What remains is deuterium depleted water.
Deuterium Oxide has the same chemical formula as any other water—H2O—with the exception that one or both of the hydrogen atoms are the deuterium isotope of hydrogen rather than the regular protium isotope (which is why heavy water is also known as deuterated water or D2O).

Physical and Chemical Characteristics:
Deuterium Oxide, also known as "heavy water", "deuterium water", is the compound of oxygen and the heavy isotope of hydrogen, namely deuterium, which is the most important deuterium compound. 
Deuterium Oxide is called heavy water because its density is heavier than ordinary and its chemical formula is D2O.
The liquid is colorless and odorless in normal temperature and pressure, containing the isotope of hydrogen with mass twice that of ordinary hydrogen. 
Compared to ordinary water, its chemical characteristic is relatively inactive with specific gravity of 1.10775 (25 ℃), melting point of 3.82 ℃, boiling point of 101.42 ℃. 

The content of Deuterium Oxide in natural water is 1/5000. The ratio of deuterium to hydrogen in ordinary water is 1:6000 and the reserve of deuterium in Dead Sea or deep sea is relatively richer. 
There is no water origin in nature with rich deuterium. 
Deuterium Oxide is similar to ordinary water in appearance but with many different physical characteristics. 

The hydrogen bond strength and degree of association between Deuterium Oxide molecules are both bigger than that of ordinary water molecules and the Deuterium Oxide has higher melting point and boiling point. 
The vapor pressure of Deuterium Oxide is smaller than that of ordinary water, which is the theoretical basis for enriching
Deuterium oxide using water distillation method. 

The viscosity of Deuterium Oxide at 25℃ is 2.3% larger than that of ordinary water making the electrical conductivity of electrolyte in Deuterium Oxide is smaller than in ordinary water and the specific inductive capacity of Deuterium Oxide is smaller than ordinary water. 
The solubility of salts in Deuterium Oxide is usually smaller and at 25 ℃ 1 g water can dissolve 0.3592 g sodium chloride while 1g Deuterium Oxide can only  dissolved 0.3592g sodium chloride. 
The distribution coefficient at 25℃ between carbon tetrachloride and water is 85:1 while 103:1 between carbon tetrachloride and deuterium oxide. 
The surface tension and ionic product ([D+7][OD+]=2×10-15) of Deuterium Oxide are both smaller than that of water and in the same chemical reaction deuterium oxide reacts more slowly than water

Main Use and Function:
Deuterium oxide can be used as neutron moderator and heat carrier in nuclear fission reactors and can also be used in chemical and biological research. 
The deuterium from Deuterium Oxide electrolysis is the charging of hydrogen bombs.
Deuterium Oxide is mainly used as moderator in nuclear reactor to reduce the neutron velocity and control the nuclear fission process and also as coolant. 
Deuterium Oxide and deuterium are valuable tracer materials in the study of chemical and physiological changes. 
For example, diluted Deuterium Oxide can run from more than ten meters to tens of meters per hour after irrigating trees with dilute water. 
The Deuterium Oxide molecule can stay in human body for 14 days on average after measuring the content of deuterium in the urine of human drinking a large amount of diluted water. 
Deuterium can be used to research the digestion and metabolism of animal and plant instead of ordinary hydrogen. 
Concentrated or pure Deuterium Oxide can not maintain the life of animals and plants and Deuterium Oxide lead animal and plant to death at the concentration of 60%.

Production Method:
Deuterium oxide resource is very rich and the content in seawater reaches 5 × 1014t. 
The purity of Deuterium Oxide in reactor is required to reach 99.75% while  the concentration of Deuterium Oxide in natural water is very low with only 0.015% And the characteristics of Deuterium Oxide production are large separation numbers, long balance time, large amount of material processing and energy consumption. 
The cost of Deuterium Oxide production depends largely on that of initial enrichment and the chosen of concentration method from natural concentration to about 1% is very important. 
There are three main Deuterium Oxide production methods as follows:

Distillation method: using the vapor pressure characteristic of deuterium compounds to enrich deuterium. 
The main raw materials are hydrogen, ammonia, water and so on. 
The distillation factor of liquid hydrogen is large but the low temperature technology and equipment limit the scale of production. Water distillation is easy and reliable to operate but the separation coefficient is too small with large energy consumption. 
The separation coefficient of ammonia distillation is slightly larger than that of water and the latent heat is small. 
But the limited ammonia source makes it uneconomical to be used for initial enrichment.

Electrolysis method: the electrolysis separation coefficient of deuterium is about 10. 
It is the main method producing deuterium oxide before the 1950’s but cannot be used  singly due to large energy consumption.
Chemical exchange method: as the the most economical way now to produce Deuterium Oxide, the actual process  is divided into single-temperature and double-temperature exchange method. 
And the double-temperature exchange process using hydrogen sulfide and water is nowadays the main method to produce low-concentration Deuterium Oxide in industrial scale. 
In addition there are other methods still in  development  such as hydrogen-adsorption alloy adsorption-separation method and laser separation method.

The cross section of deuterium for the capture of thermal neutrons is very low which makes it useful, in the form of Deuterium Oxide, as a neutron moderator in nuclear reactors. 
Produces a considerable decrease in neutron energy per collision.
Deuterium oxide is used in nuclear magnetic resonance spectroscopy (NMR). 
Deuterium Oxide is also useful in the identification of labile hydrogens. 
As a source of deuterium, it is utilized for preparing specifically labeled isotopologs of organic compounds. 
Deuterium Oxide is often used as a substitute for water in the analysis of proteins in solution by using fourier transform infrared spectroscopy (FTIR). 
Deuterium Oxide finds application in certain types of nuclear reactors and in tritium production.

Deuterium oxide (D2O) is a 100% isotopically enriched NMR (Nuclear Magnetic Resonance) solvent. It is widely employed in high resolution NMR studies. 
Various thermodynamic properties (such as intermolecular vibrational frequencies, energy of the hydrogen bond, free energy, enthalpy and entropy) of liquid deuterium oxide have been evaluated. 
Ionization constant for D2O (in the range of 5-50°C), pK values (at 25°C) and enthalpy, entropy, heat capacity change (for the dissociation of D2O) have been reported.

PHYSICAL PROPERTIES OF DEUTERIUM OXIDE:

-Molecular Weight: 20.028

-XLogP3-AA: -0.5    

-Exact Mass: 20.023118175    

-Monoisotopic Mass: 20.023118175    

-Topological Polar Surface Area: 1 Ų    

-Color: Colorless

-Form: liquid

-Odor: Odorless

-Boiling Point: 101.42 °C

-Melting Point: 3.81 °C

-Density: 1.1044

-Vapor Pressure: 20.6 mm

-Stability/Shelf Life: It is Stable under recommended storage conditions.

-Viscosity: 1.107 cP

-Surface Tension: 71.93 dyn/cm

-Refractive Index: 1.3283

Deuterium Oxide (deuterium oxide, 2H2O, D2O) is a form of water that contains only deuterium (2H or D, also known as heavy hydrogen) rather than the common hydrogen-1 isotope (1H or H, also called protium) that makes up most of the hydrogen in normal water.
The presence of the heavier hydrogen isotope gives the water different nuclear properties, and the increase of mass gives it slightly different physical and chemical properties when compared to normal water.
Dideuterium oxide is a deuterated compound and a water
Deuterium Oxide is a stable, non-radioactive isotopic form of water, containing 2 atoms of deuterium (D) and one atom of oxygen (2D2O), with DNA-labeling activity. 
Upon ingestion of deuterium oxide, 2H is incorporated into the deoxyribose moiety of DNA of newly divided cells. 
Rapidly dividing cells, as in the case of B-cell chronic lymphocytic leukemia (B-CLL), can be labeled with deuterium oxide and measured using gas chromatography and/or mass spectrometry.

CHEMICAL PROPERTIES OF DEUTERIUM OXIDE:

-Heavy Atom Count: 1    

-Formal Charge: 0    

-Complexity: 0    

-Isotope Atom Count: 2    

-Defined Atom Stereocenter Count: 0    

-Undefined Atom Stereocenter Count: 0    

-Defined Bond Stereocenter Count: 0    

-Undefined Bond Stereocenter Count: 0    

-Covalently-Bonded Unit Count: 1    

-Compound Is Canonicalized: Yes

-Hydrogen Bond Donor Count: 1    

-Hydrogen Bond Acceptor Count: 1    

-Rotatable Bond Count: 0    

STORAGE OF DEUTERIUM OXIDE:

Deuterium Oxide should be stored in a cool environment.
Deuterium Oxide should be stored in a dry place.
Deuterium Oxide can be easily stored as it is suitable for air transportation.

Deuterium Oxide should be stored in a regularly ventilated place.
Deuterium Oxide should be kept tightly closed.

Deuterium Oxide should not be stored together with strong acids.
Deuterium Oxide should be stored under constant pressure.

Deuterium Oxide should be stored at a constant temperature.
Deuterium Oxide should be stored in a place where there are no sudden temperature changes.
Deuterium Oxide should be stored in a moisture-free and dry place.

SYNONYMS:

Heavy water
Water-d2
Deuterated water
Deuterium oxide [USAN]
Water, heavy (D2-O)
Water, heavy
Deuterium oxide (USAN)
Dideuterium oxide
Heavy water-d2
D2O
Heavy water (D2O)
Deuterium oxide
Deuterium-oxide
Water (2D)
Deuterium oxide