DEUTERIUM OXIDE

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.
Deuterium oxide is a form of water in which the hydrogen atoms are replaced by deuterium, a stable isotope of hydrogen that contains one proton and one neutron.

CAS Number: 7789-20-0
Molecular Formula: D2O
Molecular Weight: 20.03
EINECS Number: 232-148-9

Synonyms: DEUTERIUM OXIDE, 7789-20-0, Heavy water, Deuterated water, Water-d2, Dideuterium oxide, Heavy water (D2O), Water-d sub(2), DTXSID4051243, J65BV539M3, CHEBI:41981, Oxide, Deuterium, RefChem:5735, DTXCID3029865, 232-148-9, Deuterium oxide [USAN], MFCD00044636, (~2~H_2_)water, D2O, Deuterium oxide (USAN), Heavy water-d2, Water(sup 2)-H2, Deuterium oxide, 99.9 atom % D, 142473-50-5, Deuterium oxide (Water-d2, Heavy Water), Deuterium oxide, "100%", 99.96 atom % D, EINECS 232-148-9, Water, heavy (D2-O), UNII-J65BV539M3, AI3-52352, HSDB 8190, DEUTERIUM OXIDE 99.8ATOM%D, (sup 2)H, WATER H-2, SCHEMBL57022, DEUTERIUM OXIDE [MI], Deuterium Oxide >99.90%, (?H)oxy, CHEMBL1232306, Deuterium oxide, 60 atom % D, Deuterium oxide, 70 atom % D, Deuterium oxide, 99 atom % D, Deuterium oxide, 99.9 atom %D, Deuterium oxide >99.96 Atom %D, Deuterium Oxide + 1% DSS (w/w), Water-d2 99.8atom%D, Heavy water, AKOS015904640, D214, SY001268, Deuterium oxide, filtered, 99.8 atom % D, W0002, W0004, D03703, H11944, A934838, Q155890, Deuterium oxide, 99.9 atom % D, ~150 dpm/mL tritium, Deuterium oxide, 100.0 atom % D, >=99.96 atom % D, Deuterium oxide, Vetec(TM) reagent grade, 99.8 atom % D, Deuterium oxide, contains 0.05 wt% D4-TMSP acid, sodium salt, 2H, Deuterium oxide, 99.9 atom % D, contains 0.05 wt. % 3-(trimethylsilyl)propionic-2,2,3,3-d4 acid, sodium salt, Deuterium oxide, 99.9 atom % D, contains 0.75 wt. % 3-(trimethylsilyl)propionic-2,2,3,3-d4 acid, sodium salt, Deuterium oxide, 99.9 atom % D, contains 1 % (w/w) 3-(trimethylsilyl)-1-propanesulfonic acid, sodium salt (DSS), Deuterium oxide, 99.994 atom % D, contains 1 mM terephthalic acid disodium salt, 0.01 % (w/v), WATER-D2;WATER, HEAVY;DEUTERIUM OXIDE, "100" (MIN. 99.96 ATOM% D);Deuterium oxide "100%" >99.98 Atom % D;Deuterium oxide >99.92 Atom % D;Heavy water, Water-d2;Deuterium oxide Ultra-D;Deuterium oxide, Heavy water, Water-d2

Deuterium oxide has a higher melting point and boiling point than ordinary water due to the stronger hydrogen–deuterium bonding network.
Deuterium oxide freezes at about 3.8 °C and boils at approximately 101.4 °C under standard pressure.
Deuterium oxides density at room temperature is around 1.105 g/cm³, which is why it is referred to as “heavy” water.

Deuterium oxide affects hydrogen bonding in biomolecules such as proteins and nucleic acids.
High concentrations can alter protein folding, enzyme kinetics, and DNA replication rates.
These effects make heavy water a useful probe in biophysical and biochemical studies.

The liquid is colorless and odorless in normal temperature and pressure, containing the isotope of hydrogen with mass twice that of ordinary hydrogen. 
Deuterium oxides chemical characteristic is relatively inactive with specific gravity of 1.10775 (25 ℃), melting point of 3.82 ℃, boiling point of 101.42 ℃. 
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. 
Heavy water is similar to ordinary water in appearance but with many different physical characteristics. 
The hydrogen bond strength and degree of association between heavy water molecules are both bigger than that of ordinary water molecules and the heavy water has higher melting point and boiling point. 

The vapor pressure of heavy water is smaller than that of ordinary water, which is the theoretical basis for enriching
Deuterium oxides chemical formula is D₂O, and it is commonly known as heavy water because it has a higher molecular mass and density than ordinary water (H₂O).
Although it appears identical to normal water in color and taste, its physical and chemical behavior differs in measurable ways.

Deuterium oxide occurs naturally in very small quantities in all natural water sources.
Deuterium oxide is produced industrially by separation processes such as electrolysis, fractional distillation, or chemical exchange methods.
Due to the difficulty of separating deuterium from hydrogen, heavy water is significantly more expensive than ordinary water.

Deuterium oxide participates in the same reactions as water but at slower rates.
The stronger O–D bonds compared to O–H bonds cause a kinetic isotope effect that alters reaction speeds and equilibrium behavior.
These differences make deuterium oxide especially valuable for studying reaction mechanisms and molecular dynamics.

Deuterium oxide is primarily used as a neutron moderator in certain nuclear reactors.
It effectively slows down neutrons without absorbing them, allowing reactors to operate using natural uranium fuel.
This makes it essential in heavy-water reactor designs such as CANDU reactors.

In scientific and medical research, deuterium oxide is widely used as an isotopic tracer.
Deuterium oxide enables tracking of metabolic pathways, water turnover, and biochemical reactions using techniques like NMR and mass spectrometry.
It is also used in protein structure studies and hydrogen–deuterium exchange experiments.

Deuterium oxide is used in spectroscopy and analytical chemistry as a solvent.
Its distinct isotopic properties reduce background signals in NMR spectroscopy.
This improves resolution and accuracy in molecular analysis.

Deuterium oxide is not radioactive and is not acutely toxic in small quantities.
However, replacing a significant fraction of body water with heavy water can disrupt normal biological processes.
High exposure interferes with cell division, enzyme activity, and metabolic reactions.

Ingestion of large amounts can lead to symptoms such as dizziness, fatigue, and nausea.
Extreme exposure may cause serious physiological effects due to altered biochemical kinetics.
For this reason, consumption is limited strictly to controlled research or medical applications.

In industrial and nuclear settings, hazards are primarily associated with handling large volumes.
Spills or leaks may pose operational and regulatory risks rather than chemical toxicity.
Proper containment, monitoring, and safety procedures are required when working with deuterium oxide.

Melting point : 3.8 °C
Boiling point : 101.4 °C
Density : 1.107 g/mL at 25 °C
Vapor pressure : 27.464 hPa at 25 °C
Refractive index : n²⁰/D = 1.328
Flash point : 101.4 °C
Storage temperature : Store below +30 °C
Form : Liquid
pKa : pK (25 °C) 14.955 (molarity scale); 16.653 (mole fraction scale)
Color : Colorless
pH : 7 (H₂O, 20 °C)
Relative polarity : 0.991
Water solubility : Miscible with water
Sensitivity : Moisture sensitive
Dielectric constant : 78.3 (25 °C)
Stability : Stable; hygroscopic
Merck Index : 14,2940
InChI : 1S/H2O/h1H2/i/hD2
InChIKey : XLYOFNOQVPJJNP-ZSJDYOACSA-N
SMILES : [²H]O[²H]

Deuterium oxide, also known as “heavy water” or “deuterium water”, is the compound of oxygen and the heavy isotope of hydrogen, called deuterium. 
Physically and chemically, heavy water is almost identical to ordinary “light” water, H₂O. 
Deuterium oxide is called heavy water because its density is greater than H₂O. 

Deuterium oxides chemical formula is D₂O.
Deuterium oxide contains one neutron and one proton in its nucleus, which makes it twice as heavy as protium (hydrogen), which contains only one proton. 
Deuterium oxide is a colorless and odorless liquid at normal temperature and pressure. 

Compared to ordinary water, its chemical characteristic is relatively inactive with a specific gravity of 1.10775 (at 25℃), melting/freezing point of 3.82℃, and a boiling point of 101.42℃. 
The hydrogen bond strength and degree of association between heavy water molecules are both stronger than that of ordinary water molecules.
Deuterium oxide using water distillation method. 

The viscosity of heavy water at 25℃ is 2.3% larger than that of ordinary water making the electrical conductivity of electrolyte in heavy water is smaller than in ordinary water and the specific inductive capacity of heavy water is smaller than ordinary water. 
The solubility of salts in heavy water is usually smaller and at 25 ℃ 1 g water can dissolve 0.3592 g sodium chloride while 1g heavy water 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 heavy water are both smaller than that of water and in the same chemical reaction deuterium oxide reacts more slowly than water. 
Just like the concentrated sulfuric acid, heavy water can absorb water and must be kept in sealed containers. 
Heavy water can be used as nuclear moderator and heat reduction lubricant in the atomic reactor.

Deuterium oxide plays an important role in isotope labeling and tracer studies.
Deuterium oxide is used to measure body water content, metabolic rates, and lipid or protein synthesis in living organisms.
Because deuterium is non-radioactive, it provides a safer alternative to radioactive tracers.

In materials science and physics, deuterium oxide is used in neutron scattering experiments.
Deuterium oxides low neutron absorption cross section allows clearer investigation of atomic and molecular structures.
This makes Deuterium oxide valuable in studying polymers, metals, and complex condensed-matter systems.

From an environmental and regulatory perspective, deuterium oxide is tightly controlled in many countries.
This is primarily due to its strategic importance in nuclear technology rather than toxicity.
Production, transport, and storage are therefore subject to licensing and international oversight.

Uses Of Deuterium oxide:
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 oxide, 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). 
It finds application in certain types of nuclear reactors and in tritium production.
Deuterium Oxide is used to prepare specifically labelled isotopologs of organic compounds.

To study chemical reaction rates and mechanisms. 
The cross section of deuterium for the capture of thermal neutrons is very low which makes it useful, in the form of heavy water, as a neutron moderator in nuclear reactors. 
Produces a considerable decrease in neutron energy per collision.

Deuterium oxide is widely used as a neutron moderator and coolant in certain nuclear reactors.
Deuterium oxide slows fast neutrons efficiently without significantly absorbing them, allowing sustained nuclear fission with natural uranium fuel.
This makes it essential in heavy-water reactor systems used for power generation and research.

In scientific and biomedical research, deuterium oxide is used as a stable isotopic tracer.
Deuterium oxide enables the study of metabolic pathways, water turnover, and biosynthesis rates in living organisms.
Because deuterium is non-radioactive, it is suitable for controlled human and animal studies.

Deuterium oxide is commonly used as a solvent in nuclear magnetic resonance (NMR) spectroscopy.
Deuterium oxide reduces background proton signals, improving spectral clarity and measurement accuracy.
This application is critical in chemistry, biochemistry, and pharmaceutical research.

In biophysics and structural biology, deuterium oxide is applied in hydrogen–deuterium exchange experiments.
These studies provide insight into protein folding, conformational changes, and molecular stability.
The technique is especially valuable for analyzing protein dynamics and interactions.

Deuterium oxide is also used in neutron scattering and materials research.
Deuterium oxides low neutron absorption allows precise investigation of atomic and molecular structures.
This supports research in polymers, soft matter, metals, and condensed-matter physics.

Deuterium oxide is used in pharmaceutical research to study drug metabolism and distribution.
By incorporating deuterium into biological systems, researchers can trace biochemical pathways and determine reaction rates with high precision.
This helps in understanding drug stability, absorption, and elimination mechanisms.

In environmental and ecological studies, deuterium oxide is applied to track water movement and turnover.
It is used to study groundwater flow, evaporation rates, and plant water uptake.
These applications support hydrological modeling and climate research.

Deuterium oxide is utilized in calorimetry and thermodynamic studies.
Its different heat capacity and phase-transition behavior compared to ordinary water allow detailed analysis of energy transfer processes.
This is useful in both physical chemistry and materials science research.

In biotechnology, deuterium oxide is employed to produce deuterium-labeled biomolecules.
These labeled compounds are essential for advanced spectroscopic techniques and kinetic studies.
They help clarify molecular mechanisms that cannot be resolved using normal hydrogen.

Deuterium oxide is also used in fusion research and plasma physics.
It serves as a source of deuterium for experimental fusion reactions and isotopic studies.
This application supports the development of future nuclear fusion energy technologies.

Safety Profile Of Deuterium oxide:
Deuterium oxide is not radioactive and does not pose a hazard at low exposure levels.
Small amounts can be safely handled and are routinely used in laboratory and medical research.
The primary risks arise only when a significant fraction of body water is replaced with heavy water.

High intake of deuterium oxide can disrupt normal biochemical processes.
The presence of deuterium alters hydrogen bonding and slows enzyme-catalyzed reactions.
This can interfere with cell division, protein synthesis, and metabolic regulation.

Exposure to large quantities may lead to symptoms such as dizziness, fatigue, nausea, and impaired coordination.
Very high concentrations can cause serious physiological effects and may be life-threatening.
For this reason, ingestion is strictly limited to controlled research conditions.

In industrial and nuclear facilities, hazards are mainly associated with handling large volumes.
Deuterium oxide spills or leaks can create operational, regulatory, and environmental concerns rather than acute toxicity.
Proper containment, monitoring systems, and safety protocols are required when working with deuterium oxide.