PRODUCTS

HYPOPHOSPHORUS ACID

Hypophosphorous acid is also known as "hypophosphite" It is colorless oil or deliquescence crystal, it is an important fine chemical product.
Hypophosphorous acid, or phosphinic acid, is a phosphorus oxyacid and a powerful reducing agent with molecular formula H3PO2.
Hypophosphorous acid is a colorless low-melting compound, which is soluble in water, dioxane and alcohols.

CAS Number: 6303-21-5
Molecular Formula: H3PO2
Molecular Weight: 63.980501
EINECS Number: 228-601-5

Hypophosphorous acid, also known as phosphinic acid, is a chemical compound with the formula H3PO2.
Hypophosphorous acid is a phosphorus oxyacid and is structurally similar to phosphoric acid (H3PO4) but has one less oxygen atom.
The chemical structure of hypophosphorous acid consists of a central phosphorus atom bonded to three hydrogen atoms and one hydroxyl group (-OH).

Hypophosphorous acid, a monobasic oxyacid, is also referred to as phosphinic acid.
Hypophosphorous acid participates as a reducing agent for the conversion of aromatic and aliphatic diselenides to the corresponding selenols.
Hypophosphorous acid undergoes oxidation in the presence of Ce(IV) and a strong acid to afford cerium(IV) hypophosphite complex ions.

The main use Hypophosphorous acid is as reducing agent for electroless plating, phosphoric prevent discoloration of resins, it can also be used in the esterification reaction catalyst, the refrigerant, in particular for the production of high purity product sodium hypophosphite.
There are several methods for preparation, the common industrial method for producing is ion exchange resin method and electrodialysis method.
The formula for Hypophosphorous acid is generally written H3PO2, but a more descriptive presentation is HOP(O)H2, which highlights its monoprotic character.

Salts derived from this acid are called hypophosphites.
Hypophosphorous acid is a colorless, odorless liquid at room temperature and is typically found in a solution form.
Hypophosphorous acid exists in equilibrium with the minor tautomer HP(OH)2.

Sometimes the minor tautomer is called hypophosphorous acid and the major tautomer is called phosphinic acid.
Hypophosphoric acid is a mineral acid with phosphorus in an oxidation state of +4.
In the solid-state, it exists as a dihydrate, H4P2O6.2H2O.

Hypophosphorous acid can be manufactured by reacting red phosphorus with sodium chlorite at room temperature.
In this short piece of article, let us discuss the hypophosphoric acid formula along with its chemical structure, properties and uses.
Hypophosphorous acid is a powerful reducing agent with a molecular formula of H3PO2.

Inorganic chemists refer to the free acid by this name although its IUPAC name is dihydridohydroxidooxidophosphorus, or the acceptable name of phosphinic acid.
Hypophosphorous acid is a colorless low-melting compound, which is soluble in water, dioxane, and alcohols.
A Hypophosphorous acid that consists of a single pentavalent phosphorus covalently bound via single bonds to two hydrogens and a hydroxy group and via a double bond to an oxygen.

The parent of the class of Hypophosphorous acids.
Hypophosphorous acid appears as colorless oily liquid or deliquescent crystals with a sour odor.
Inhalation of vapors irritates or burns the respiratory tract.

Hypophosphorous acid is miscible with water in all proportions and a commercial strength is 30% H3PO2.
Hypophosphites are used in medicine.
Hypophosphorous acid is a powerful reducing agent, e.g., with copper sulfate forms cuprous hydride Cu2H2, brown precipitate, which evolves hydrogen gas and leaves copper on warming; with silver nitrate yields finely divided silver; with sulfurous acid yields sulfur and some hydrogen sulfide; with sulfuric acid yields sulfurous acid, which reacts as above; forms manganous immediately with permanganate.

Hypophosphorous acid (HPA) also known as phosphonic acid is a phosphorous oxoacid and also acts as a good reducing agent.
Hypophosphorous acid is basically a colourless aqueous solution that is soluble in water, dioxin as well as in alcohol.
The hypophosphorous acid formula which is the same for phosphinic acid formula is H3PO2 is a neutral molecule with no spare charge on it.

Thus the oxidation number of the central atom phosphorus is +1 which can be described as follows.
Hypophosphorous acid is a white crystalline solid.
Hypophosphorous acid is a monobasic acid forming the anion H2PO2 – in water.

The sodium salt, and hence Hypophosphorous acid, can be prepared by heating yellow phosphorus with sodium hydroxide solution.
The free acid and its salts are powerful reducing agents.
Hypophosphorous acid is primarily used for electroless nickel plating.

Hypophosphorous acid is involved in the reduction of arenediazonium salts.
Hypophosphorous acid acts as an additive in Fischer esterification reactions.
Also, Hypophosphorous acid serves as a neutralizing agent, antioxidant, catalyst in polymerization and poly condensation, and wetting agent.

Further, Hypophosphorous acid is used in the formulation of pharmaceuticals, discoloration of polymers, water treatment and retrieval of precious or non-ferrous metals.
In addition to this, it is used as bleaching agents for plastics, synthetic fibers, decolorizing agent and for color stabilization during the manufacture of chemicals and several plastics.
Hypophosphorous acid has the differs from the other oxy-phosphorous acids.

Hypophosphorous acid has many peculiarities.
Hypophosphorous acid is formed along with phosphorous and phosphoric acids, when phosphorus is oxidized by moist air.
If white phosphorus is exposed to air, and sodium acetate is addedto the liquidwhich forms, the somewhat insoluble sodium hypophosphate,Na2H2P2O6·6H2Oseparates.

The sodium hypophosphate monohydrate, however, is very soluble and deliquescent at ～98.7 g/100 ml.
Hypophosphorous acid is deliquescent crystals or colorless oil.
Hypophosphorous acid is soluble in water, ethanol and ether, and it can be mixed in any proportion with water, ethanol, acetone.

In the air, it easily deliquesce to syrupy liquid, and the aqueous solution is acidic.
Hypophosphorous acid is monobasic acid, in aqueous solution, Hypophosphorous acid is strong acid, Ka = 10-2 (25℃); it is relatively stable at room temperature; disproportionation reaction can proceed at 130℃, decompose into phosphine and phosphorous acid:
2H3PO2=H3PO4+PH3

Hypophosphorous acid has strong reduction, heavy metal salt solution can be restored to metals such as Cu2 +, Hg2 +, Ag +, such as: 4Ag+H3PO2+2H2)=4Ag+H3PO4+4H+
Hypophosphorous acid is weak oxidizer, it can be reduced to phosphine, phosphine when encounters strong reducing agent.
The molecule displays P(═O)H to P–OH tautomerism similar to that of phosphorous acid; the P(═O) form is strongly favoured.

Hypophosphorous acid is usually supplied as a 50% aqueous solution and heating at low temperatures (up to about 90°C) prompts it to react with water to form phosphorous acid and hydrogen gas.
H3PO2 + H2O → H3PO3 + H2

Heating above 110°C causes hypophosphorous acid to undergo disproportionation to give phosphorous acid and phosphine.
3 H3PO2 → 2 H3PO3 + PH3
Most metal-hypophosphite complexes are unstable, owing to the tendency of hypophosphites to reduce metal cations back into the bulk metal.

Some examples have been characterised, including the important nickel salt [Ni(H2O)6](H2PO2)2.
Hypophosphorous acid is an effective reducing agent in chemical reactions.
Hypophosphorous acid can reduce various metal ions to their lower oxidation states.

This property makes Hypophosphorous acid valuable in processes like the reduction of noble metals (e.g., silver and gold) and metal complexes in analytical chemistry and metal purification.
Hypophosphorous acid is more stable in solution compared to its salts (hypophosphites).
The salts of hypophosphorous acid are often less stable and can decompose over time.

Hypophosphorous acid is typically synthesized through the hydrolysis of phosphorus trichloride (PCl3) or the reaction of phosphine (PH3) with water:
PCl3 + 3H2O → H3PO2 + 3HCl
PH3 + 2H2O → H3PO2 + 3H2

It is important to store hypophosphorous acid in containers made of materials that are resistant to corrosion by acids, such as glass or certain plastics.
Additionally, it should be stored away from heat, open flames, and strong oxidizing agents.
Hypophosphorous acid should be handled with care due to its corrosive and reducing properties.

When working with it, proper personal protective equipment, such as gloves and safety goggles, should be worn.
Hypophosphorous acid can be used to reduce transition metal ions, which is valuable in colorimetric and titrimetric analysis methods.
Hypophosphorous acid can help determine the concentration of metal ions in various samples.

Melting point: -25 °C
Boiling point: 108 °C (759.8513 mmHg)
Density: 1.206 g/mL at 20 °C(lit.)
vapor pressure: <17 mmHg ( 20 °C)
storage temp.: no restrictions.
pka: pK1 1.1.
form: hygroscopic crystals or colorless oily liquid
color: Colorless
Water Solubility: SOLUBLE
Merck: 13,4894
Stability: Stable. Incompatible with strong bases. Reacts violently with oxidizing agents, strong bases, mercury (II) nitrate and mercury (II) oxide. Do not heat above 100 C.
InChIKey: GQZXNSPRSGFJLY-UHFFFAOYSA-N
CAS DataBase Reference: 6303-21-5(CAS DataBase Reference)
EWG's Food Scores:1

Hypophosphorous acid is a weak acid composed of phosphorous and hydrogen.
Hypophosphorous acid is an important chemical intermediate in organic synthesis and is used in a variety of industrial applications.
Hypophosphorous acid is also known as phosphinic acid and is a colorless, odorless liquid with a melting point of -31°C.

In its pure form, Hypophosphorous acid is highly reactive, making it useful in a range of chemical reactions.
Hypophosphorous acid can be synthesized from phosphorous acid and hydrogen peroxide, or from phosphorous pentoxide and water.
Hypophosphorous acid can also be produced by the reaction of phosphorus with sulfuric acid or by the oxidation of phosphite.

The most common method for the synthesis of Hypophosphorous acid is the reaction of phosphorus with sulfuric acid.
This reaction produces a solution of Hypophosphorous acid and phosphoric acid.
Hypophosphorous acid is also known as hydrogen phosphite because of its chemical structure, which includes the hydrogen ion (H+) bonded to the phosphite ion (H2PO2-).

The term "hypophosphorous" refers to the fact that it has one less oxygen atom than phosphorous acid (H3PO3).
Hypophosphorous acid participates in redox (reduction-oxidation) reactions, where it can donate electrons to other substances.
Hypophosphorous acid can act as a reducing agent, helping to convert higher-valence metal ions to lower-valence states.

This property is valuable in a variety of chemical transformations.
Hypophosphorous acid can react with atmospheric oxygen over time, leading to the formation of phosphoric acid (H3PO4) and water.
Therefore, it should be stored in airtight containers to minimize this decomposition.

Hypophosphorous acid finds applications in analytical chemistry for its ability to stabilize certain compounds and act as a reducing agent in various analytical methods, such as in the determination of various metals in complex samples.
Hypophosphorous acid is commercially available in various concentrations, often as an aqueous solution.
The concentration can range from relatively dilute solutions to more concentrated forms, depending on the intended application.

Hypophosphorous acid is compatible with certain metals and is often used for metal surface treatments and electroless plating.
Hypophosphorous acid can provide a uniform and adherent metal coating on surfaces, which is valuable in applications such as printed circuit board (PCB) manufacturing.
Hypophosphorous acid is widely used in industries that require precision metal deposition, such as the electronics industry for making electrical connections and in the automotive industry for coating parts to improve their corrosion resistance.

Hypophosphorous acid can be written as H3PO2, which represents its molecular formula, indicating the presence of three hydrogen atoms, one phosphorus atom, and two oxygen atoms.
Hypophosphorous acid is formed by reaction of barium hypophosphite and sulfuric acid, and filtering off barium sulfate.
By evaporation of the solution in vacuum at 80 °C, and then cooling to 0°C, hypophosphorous acid crystallizes.

Hypophosphorous acid is used in a variety of scientific research applications.
Hypophosphorous acid is used in organic synthesis as a reagent for the preparation of a wide range of organic compounds.
Hypophosphorous acid is also used as a catalyst in the synthesis of polymers and other materials.

Hypophosphorous acid has also been used in the preparation of pharmaceuticals, especially in the synthesis of antibiotics.
In addition, Hypophosphorous acid is used in the synthesis of dyes, pigments, and other materials.
Hypophosphorous acid has been studied for its biochemical and physiological effects.

In animal studies, Hypophosphorous acid has been shown to have anti-inflammatory, anti-oxidant, and anti-tumor properties.
Hypophosphorous acid has also been shown to have an effect on the immune system, as it has been found to increase the production of interferon gamma, a cytokine involved in the regulation of the immune system.
Hypophosphorous acid has several advantages for use in laboratory experiments.

Hypophosphorous acid is a relatively inexpensive reagent, and it is widely available.
Hypophosphorous acid is also relatively stable and has a low toxicity.
However, there are some limitations to its use in laboratory experiments.

Hypophosphorous acid is a strong acid and can be corrosive, so it must be handled with care.
Hypophosphorous acid is also a highly reactive reagent and can react with other compounds, so it must be used with caution.
There are several potential future directions for the use of Hypophosphorous acid.

Hypophosphorous acid could be used in the synthesis of new pharmaceuticals, dyes, and pigments.
Hypophosphorous acid could also be used in the development of new materials, such as polymers and nanomaterials.

Hypophosphorous acid could also be used in the development of new catalysts for organic synthesis.
Finally, it could be used in the development of new biotechnologies, such as gene editing and gene therapy.

Preparation Method Of Hypophosphorous Acid:
Hypophosphorous acid may be prepared by various methods:
1. Boiling white phosphorus with calcium hydroxide:
P4 + 4Ca(OH)2 + 8H2O → 4Ca(H2PO2)2 + 4H2

The calcium salt is soluble in water.
Treatment with sulfuric acid yields thehypophosphorous acid:
(H2PO2)2Ca + H2SO4 → 2H3PO2 + CaSO4

The product mixture is filtered to remove insoluble CaSO4.
The aqueous solu-tion of hypophosphorous acid is concentrated under reduced pressure.
Concentrated baryta water may be used instead of calcium hydroxide.

2. By treating sodium hypophosphite, NaH2PO2with an ion-exchange resin.
The sodium salt may be produced by boiling white phosphorus with a solutionof sodium hydroxide, a reaction similar to (1) above.
PH3 + 2I2 + 2H2O → H3PO2 + 4HI

The above method may be considered safer than that involving heating whitephosphorus with an alkali.
Hypophosphorous acid must be stored below 50°C.
It is sold commerciallyas an aqueous solution at various concentrations.

Hypophosphorous acid was first prepared in 1816 by the French chemist Pierre Louis Dulong (1785–1838).
The acid is prepared industrially via a two step process: Firstly, elemental white phosphorus reacts with alkali and alkaline earth hydroxides to give an aqueous solution of hypophosphites:
P4 + 4 OH− + 4 H2O → 4 H2PO−2 + 2 H2

Any phosphites produced in this step can be selectively precipitated out by treatment with calcium salts.
The purified material is then treated with a strong, non-oxidizing acid (often sulfuric acid) to give the free hypophosphorous acid:
H2PO−2 + H+ → H3PO2

Hypophosphorous acid is usually supplied as a 50% aqueous solution.
Anhydrous acid cannot be obtained by simple evaporation of the water, as the acid readily oxidises to phosphorous acid and phosphoric acid and also disproportionates to phosphorous acid and phosphine.
Pure anhydrous hypophosphorous acid can be formed by the continuous extraction of aqueous solutions with diethyl ether.

Uses Of Hypophosphorous Acid:
Hypophosphorous acid is used as reducing agent for electroless plating.
Hypophosphorous acid can be used to prevent discoloration of phosphoric acid resin.
Hypophosphorous acid is used as esterification catalyst, the refrigerant.

Hypophosphorous acid is used to produce hypophosphite, sodium salts, manganese salts, iron salts are generally used as nourishing substances.
Hypophosphorous acid is used in medicine and as reducing agent, the determination of arsenic, tellurium and separation of tantalum, niobium and other reagents.
Hypophosphorous acid is strong reducing agent, It can be used for the preparation of sodium hypophosphite, calcium phosphate and other hypophosphite.

Hypophosphorous acid can be used for the plating bath. Pharmaceuticals. reducing agent. general reagents.
Hypophosphorous acid is strong reducing agent, it can be used in making sodium hypophosphite, calcium phosphate and other hypophosphite.
Hypophosphorous acid is widely used as reducing agent, Ag, Cu, Ni, Hg and other metals are reduced to the corresponding metal, for the verification of As, Nb, Ta and other reagents, it can be used for the preparation of Na, K, Ca, Mn, Fe and other types of hypophosphite.

Hypophosphorous acid is used in electroless nickel plating, where it helps deposit a layer of nickel onto various surfaces without the need for an electrical current.
This process is widely used in industries such as electronics and automotive manufacturing.
Hypophosphorous acid is used to remove dissolved oxygen from water in industrial applications, as oxygen can corrode equipment and pipelines.

Hypophosphorous acid is used as a reducing agent in the production of certain polymers, such as polyamides (nylon) and polyurethanes.
Hypophosphorous acid may be employed in the synthesis of some pharmaceutical compounds.
Hypophosphorous acid (and its salts) are used to reduce metal salts back into bulk metals.

Hypophosphorous acid is effective for various transition metals ions (i.e. those of: Co, Cu, Ag, Mn, Pt) but is most commonly used to reduce nickel.
This forms the basis of electroless nickel plating (Ni–P), which is the single largest industrial application of hypophosphites.
For this application it is principally used as a salt (sodium hypophosphite).

One of the primary applications of hypophosphorous acid is in electroless plating, where it is used to deposit metal coatings (typically nickel) onto various surfaces without the need for an external electrical current.
This process is crucial in industries like electronics, where it is used for PCB manufacturing, and in the automotive industry for coating components with corrosion-resistant metal layers.
Hypophosphorous acid is employed in water treatment to remove dissolved oxygen from water.

Oxygen can lead to corrosion of pipes and equipment in industrial settings.
By reducing the oxygen content in water, hypophosphorous acid helps prevent corrosion.
Hypophosphorous acid serves as a reducing agent in various chemical reactions.

Hypophosphorous acid can reduce metal ions from higher oxidation states to lower oxidation states, making it valuable in processes involving the purification of metals, metal recovery from solutions, and the synthesis of metal complexes.
In organic and inorganic synthesis, hypophosphorous acid is used to reduce or stabilize certain compounds.
Hypophosphorous acid can be a component in the synthesis of various chemicals, including pharmaceuticals.

Hypophosphorous acid is utilized in analytical chemistry techniques.
Hypophosphorous acid can reduce metal ions to facilitate their detection and quantification, particularly in colorimetric and titrimetric analysis methods.
Hypophosphorous acid is used as a reducing agent in the production of certain polymers, such as polyamides (commonly known as nylon) and polyurethanes.

Hypophosphorous acid was used as a reducing agent to stabilize and develop photographs.
Hypophosphorous acid can be used in chemical etching processes to selectively remove metal layers from surfaces, leaving behind desired patterns or designs.
Hypophosphorous acid and its salts can serve as catalysts in various chemical reactions, including hydrogenation and dehydrogenation reactions.

Hypophosphorous acid is used in some dyeing and printing processes in the textile industry.
Hypophosphorous acid is primarily used for electroless nickel plating.
Hypophosphorous acid is involved in the reduction of arenediazonium salts.

Hypophosphorous acid acts as an additive in Fischer esterification reactions.
Also, it serves as a neutralizing agent, antioxidant, catalyst in polymerization and poly condensation, and wetting agent.

Toxicity Of Hypophosphorous Acid:
Hypophosphorous acid is non-combustible.
But when contacts with the hole H agent, it will cause fire. When meets oxidizing agent, violent reaction and combustion can proceed.
When it is heated to high, it can decompose into highly toxic phosphine gas, or even explode.

Hypophosphorous acid is corrosive.
Hypophosphorous acid is often added into soft drinks, and because it is not absorbed.
So the risk is small, but particularly strong hypophosphite hurt gastrointestinal.

Accidentally Hypophosphorous acid splashes into the eyes or contacts skin, plenty of water is used to washed.
Production operators should wear protective clothing and other protective clothing.
Production equipment should be sealed, workshop should be ventilated well.

Hazards Of Hypophosphorous Acid:
Hypophosphorous acid is corrosive to the skin, eyes, and mucous membranes.
Contact with concentrated solutions can cause burns, irritation, and tissue damage.
Proper protective equipment, such as gloves and safety goggles, should be worn when handling this chemical.

Inhalation of hypophosphorous acid vapors or mists can irritate the respiratory tract and lead to coughing, shortness of breath, and respiratory discomfort.
Work in well-ventilated areas, and use appropriate respiratory protection if necessary.
Hypophosphorous acid is a reducing agent, which means it can react vigorously with oxidizing agents and materials.

Hypophosphorous acid can decompose, especially when exposed to heat and air.
This decomposition can release phosphine gas (PH3), which is highly toxic and flammable.
Spills of hypophosphorous acid can have environmental consequences, it may contaminate soil and water, leading to adverse effects on aquatic life and the environment.

Synonyms Of Hypophosphorous Acid:
14097-15-5
phosphenous acid
Hypophosphite ion
Hypophosphorus acid
hydroxyphosphanone
Phosphine oxide, hydroxy-
Phosphinic acid, ion(1-)
15460-68-1
UNII-238U65NZ04
DTXSID4043808
NSC-41904
238U65NZ04
68412-69-1
UNII-6A37X7BT86
EINECS 270-204-4
EINECS 270-206-5
hydroxidooxidophosphorus
dihydridodioxophosphate(1-)
dihydridodioxidophosphate(1-)
[P(O)OH]
CHEMBL2105054
DTXCID2023808
CHEBI:29198
CHEBI:36363
DTXSID50165673
HYPOPHOSPHOROUS ACID [MI]
ACVYVLVWPXVTIT-UHFFFAOYSA-M
GQZXNSPRSGFJLY-UHFFFAOYSA-N
6A37X7BT86
NSC41904
PH2O2(-)
HYPOPHOSPHOROUS ACID [WHO-DD]
Hypophosphorous Acid, Phosphinic Acid
[PH2O2](-)
FT-0626449
Phosphinic acid, for synthesis, 49.5-50.5%
J-521481
Q3305467
Q27116796
Q27117120
Phosphinic acid, puriss. p.a., 49.5-50.5% (alkalimetric)
Phosphinic acid, puriss., meets analytical specification of NF, 30-32%