PHOSPHORUS PENTOXIDE

Phosphorus pentoxide is a chemical compound with molecular formula P4O10 (with its common name derived from its empirical formula, P2O5). 
This white crystalline solid is the anhydride of phosphoric acid.
Phosphorus pentoxide is a powerful desiccant and dehydrating agent.

CAS Number:  1314-56-3 
EC number:  215-236-1
IUPAC Name: 2,4,6,8,9,10-Hexaoxa-1λ5,3λ5,5λ5,7λ5-tetraphosphatricyclo[3.3.1.13,7]decane 1,3,5,7-tetraoxide
Chemical Formula: P4O10

Other names: Tetraphosphorus decaoxide, 16752-60-6, Diphosphorus pentoxide, Phosphorpentoxid, P4O10, P2O5, 2,4,6,8,9,10-hexaoxa-1lambda5,3lambda5,5lambda5,7lambda5-tetraphosphatricyclo[3.3.1.13,7]decane 1,3,5,7-tetraoxide, Phosphorous pentoxide, Phosphor(V)-oxid, diphosphorous pentoxide, SCHEMBL1006, Phosphorus oxide (P4O10), TETRAPHOSPHORUSDECAOXIDE, CHEBI:37376, DTXSID701335584, P4 O10, (P2O5)2, Q369309, Phosphorus pentoxide, >=99.99% trace metals basis, tricyclo[3.3.1.1(3,7)]tetraphosphoxane 1,3,5,7-tetraoxide, 2,4,6,8,9,10-hexaoxa-1,3,5,7-tetraphosphatricyclo[3.3.1.1(3,7)]decane 1,3,5,7-tetraoxide

Phosphorus pentoxide crystallizes in at least four forms or polymorphs. 
The most familiar one, a metastable form (shown in the figure), comprises molecules of P4O10. 
Weak van der Waals forces hold these molecules together in a hexagonal lattice (However, in spite of the high symmetry of the molecules, the crystal packing is not a close packing). 
The structure of the P4O10 cage is reminiscent of adamantane with Td symmetry point group.

Phosphorus pentoxide is closely related to the corresponding anhydride of phosphorous acid, P4O6. 
Phosphorus pentoxide latter lacks terminal oxo groups. Its density is 2.30 g/cm3. 
Phosphorus pentoxide boils at 423 °C under atmospheric pressure; if heated more rapidly it can sublimate.
Phosphorus pentoxide form can be made by condensing the vapor of phosphorus pentoxide rapidly, and the result is an extremely hygroscopic solid.

Phosphorus pentoxide other polymorphs are polymeric, but in each case the phosphorus atoms are bound by a tetrahedron of oxygen atoms, one of which forms a terminal P=O bond involving the donation of Phosphorus pentoxide terminal oxygen p-orbital electrons to the antibonding phosphorus-oxygen single bonds. 
The macromolecular form can be made by heating the compound in a sealed tube for several hours, and maintaining the melt at a high temperature before cooling the melt to the solid.

The metastable orthorhombic "O"-form (density 2.72 g/cm3, melting point 562 °C) adopts a layered structure consisting of interconnected P6O6 rings, not unlike the structure adopted by certain polysilicates. 
The stable form is a higher density phase, also orthorhombic, the so-called O' form. 
Phosphorus pentoxide consists of a 3-dimensional framework, density 3.5 g/cm3. 
Phosphorus pentoxide remaining polymorph is a glass or amorphous form; it can be made by fusing any of the others.

Preparation
P4O10 is prepared by burning tetraphosphorus with sufficient supply of oxygen:
P4 + 5 O2 → P4O10

For most of the 20th century, phosphorus pentoxide was used to provide a supply of concentrated pure phosphoric acid. In the thermal process, the phosphorus pentoxide obtained by burning white phosphorus was dissolved in dilute phosphoric acid to produce concentrated acid.
Improvements in filter technology is leading to the "wet phosphoric acid process" taking over from the thermal process, obviating the need to produce white phosphorus as a starting material.
Phosphorus pentoxide dehydration of phosphoric acid to give phosphorus pentoxide is not possible as on heating metaphosphoric acid will boil without losing all its water.

Applications
Phosphorus pentoxide is a potent dehydrating agent as indicated by the exothermic nature of its hydrolysis:
P4O10 + 6 H2O → 4 H3PO4   (–177 kJ)

However, its utility for drying is limited somewhat by its tendency to form a protective viscous coating that inhibits further dehydration by unspent material. 
A granular form of P4O10 is used in desiccators.

Consistent with its strong desiccating power, P4O10 is used in organic synthesis for dehydration. 
Phosphorus pentoxide most important application is for the conversion of primary amides into nitriles:
P4O10 + RC(O)NH2 → P4O9(OH)2 + RCN

Phosphorus pentoxide indicated coproduct P4O9(OH)2 is an idealized formula for undefined products resulting from the hydration of P4O10.
Alternatively, when combined with a carboxylic acid, the result is the corresponding anhydride:
P4O10 + RCO2H → P4O9(OH)2 + [RC(O)]2O

Phosphorus pentoxide "Onodera reagent", a solution of P4O10 in DMSO, is employed for the oxidation of alcohols.
This reaction is reminiscent of the Swern oxidation.

The desiccating power of P4O10 is strong enough to convert many mineral acids to their anhydrides.
Examples: HNO3 is converted to N2O5;  H2SO4 is converted to SO3;  HClO4 is converted to Cl2O7; CF3SO3H is converted to (CF3)2S2O5.

Agriculture
Phosphorus pentoxide compound can be used as crop fertilizer.

Related phosphorus oxides
Between the commercially important P4O6 and P4O10, phosphorus oxides are known with intermediate structures.

On observation it will be seen that double bonded oxygen in at 1,2 position or 1,3 position are identical and both positions have same steric hindrance. Cycle 12341 and ABCDA are identical.

Hazards
Phosphorus pentoxide itself is not flammable. Just like sulfur trioxide, it reacts vigorously with water and water-containing substances like wood or cotton, liberates much heat and may even cause fire due to the highly exothermic nature of such reactions. 
Phosphorus pentoxide is corrosive to metal and is very irritating – it may cause severe burns to the eye, skin, mucous membrane, and respiratory tract even at concentrations as low as 1 mg/m3.

General description
Phosphorus pentoxide is a deliquescent compound prepared by reacting phosphorus with air. 
Phosphorus pentoxide is a commonly used as dehydrating and condensing agent in organic synthesis.
Application
Phosphorus pentachloride has been used for the vaccum distillation of 1-methyl-2-pyrrolidinone (NMP), which was employed as mobile phase in a chromatographic analysis.

Phosphorus pentoxide may be used as one of the reaction components in the synthesis of dichlorine heptoxide (Cl2O7) and transition-metal phosphides (Ni2P, Co2P and MoP). 
P2O5 supported on alumina can be used for the solvent-free and microwave-assisted preparation of 1, 5-benzodiazepine analogs. P2O5/KX (X = Br, I) reagent system may be used for the transformation of alcohols into the corresponding alkyl iodides and bromides.

Phosphorus pentoxide/methanesulfonic acid (PPMA) may be used as a condensing agent and solvent for the synthesis of:
High molecular weight poly(benzoxazole)s via direct polycondensation of aromatic dicarboxylic acids containing phenyl ether structure with 3,3′-dihydroxybenzidine dihydrochloride.
Aromatic poly(phenylene ether ether ketone)s via direct self-polycondensation of 4-(4′-phenoxyphenoxy)benzoic acids.
1,3-1H-dibenzimidazole-benzene by the reaction of isophthalic acid with 1,2-diaminobenzene.

Inorganic acids and anhydrides thereof should first be diluted or hydrolyzed by stirring carefully into ice water and then neutralized (protective gloves, fume cupboard!) with sodium hydroxide solution (Cat. No. 105587). 
Before filling into container D, check the pH with pH universal indicator strips (Cat. No. 109535).
 
Fuming sulfuric acid should be carefully stirred dropwise into 40 % sulfuric acid (Cat. No. 109286). 
Ensure that plenty of ice is available for cooling! When sufficiently cool, treat the highly concentrated sulfuric acid as described above. 
Analogous to this procedure, other anhydrides can be converted into their corresponding acids. 
Acid gases (e.g. hydrogen halide, chlorine, phosgene, sulfur dioxide) can be introduced into dilute sodium hydroxide solution and after neutralization disposed of in container D.

Phosphorus pentoxide is a white, microcrystalline, light weight powder which is produced by the combustion of elemental phosphorus in an excess of oxygen. 
Phosphorus pentoxide is the anhydride of orthophosphoric acid, H3PO4. It is very hygroscopic and is converted by water to H3PO4 via intermediates. 
The reaction with water is very vigorous and proceeds with the evolution of a large amount of heat.

Due to its highly hygroscopic and microcrystalline character, the capability of flowing of P2O5 may vary in a certain range. 
Furthermore, the formation of soft agglomerates, which come apart under slight pressure, is not preventable.

Benefits
Wide variety of applications as a reagent in the chemical industry

What Is Phosphorus Pentoxide?
Phosphorus Pentoxide (P2O5) is a white soft powder chemical compound used in a wide variety of applications as a building block and a reagent in the chemical industry.

Phosphorus is a nonmetallic element that exists in three forms: elemental phosphorus, white phosphorus, and red phosphorus. 
White phosphorus, which is also referred to asyellow phosphorus, is widely used in munitions manufacturing, in fireworks, as an ingredient in methamphetamine production, and in fertilizers. 
Historically, it has also been used as a rodenticide. 
The autoignition temperature (the temperature at which spontaneous combustion can occur) is 30°C (86°F). 

When white phosphorus comes in contact with air at temperatures above the autoignition point, the phosphorus spontaneously oxidizes, forming phosphorus pentoxide. 
Phosphorus pentoxide can combine with small amounts of moisture in the air, forming phosphoric acid. 
In wounds, oxidation of phosphorus pentoxide will continue until it is removed through débridement, neutralized, or consumed.

Phosphorus pentoxide is a dehydrating agent often used as a dessicant for bacterial cultural extracts analyzed by gas-liquid chromatography.

This monograph for Phosphorus Pentoxide provides, in addition to common physical constants, a general description including typical appearance, applications, and aqueous solubility. 
The monograph also details the following specifications and corresponding tests for verifying that a substance meets ACS Reagent Grade specifications including: Assay, Insoluble Matter, Phosphorus Trioxide, Ammonium, and Heavy Metals.

Product Description
We feel immensely pleased to manufacture and supply an exclusive gamut of Phosphorus Pentoxide (P2O5). 
This product is provided to the clients in the following:

Specification:
Appearance: White Power
Physical State: White Hygroscopic Powder

Features:
Exact composition
No foreign particles
Effectiveness

Phosphorus Pentoxide (Phosphorus(V) Oxide) is a dehydrating agent used in organic synthesis, primarily in converting primary amides into nitriles and mineral acids into their anhydrides.

Phosphorus pentoxide is a phosphorous oxide. Phosphorus pentoxide is used as a strong drying and dehydrating agent. 
Many reactions that require the removal of a water molecule can utilize P2O5 such as the dehydration of amides to nitriles. 
Phosphorus pentoxide is primarily used in making optical glass and heat-insulating glass. In addition, phosphorus pentoxide is a key ingredient to produce pharmaceuticals and pesticides in the pharma and agricultural industry.

Stored phosphorus pentoxide is going to be covered with polyphosphoric acid like a skin. If this "skin" is removed with a pair of tweezers you will again find a proper compond. 
"The-more-the-better"-user will often produce this kind of problem in desiccators, where a half pound of phosphorus pentoxid used as drying agent is soon without any effect, since it is separated from the scene by the "skin".

If you attempt to deactivate phosphorus pentoxide with water, you are penalised with lots of smoke, coughing, angry lab-neighbors and maybe also a broken glas container because phosphorus pentoxide reacts vigorously with water. 
Phosphorus pentoxide  is better to leave the compond standing alone in contact with air and wait until it is hydrolysed by air moisture. 
Phosphorus pentoxide  the powder has completely changed to a syrup, you may add riskless more water.
Batches which are completely decomposed are disposed in a separate bottle.

Phosphorus pentoxide a white, deliquescent, crystalline powder, P2O5, that, depending upon the amount of water it absorbs, forms orthophosphoric acid, metaphosphoric acid, or pyrophosphoric acid, produced by the burning of phosphorus in dry air: used in the preparation of phosphoric acids, as a drying and dehydrating agent, and in organic synthesis.

Application: Chip N type doping Phosphorus source of semiconductor, solar cells, raw materials of laser crystal growth , such as KDP, KTP, DKDP , can also be used for medicine, cosmetics production and preparation of high purity phosphoric acid.

Engineering Controls
Use a fume hood when working with phosphorus pentoxide. 
Ensure the fume hood has proper air flow by checking the flow rate on the control panel and / or using a smoke match or wipe to visualize flow.

We use phosphorus pentoxide when making 100% phosphoric acid which can be a messy affair. 
In this case, the fume hood is convenient to keep everything contained for easier cleanup, not for protection against fumes.

Administrative Controls
Tape a sign to the outside of the fume hood sash indicating that you are making phosphoric acid. 
Phosphorus pentoxide  process often takes more than one day.

Personal Protective Equipment (PPE)
Wear a lab coat, nitrile gloves, and eye protection

Keep container tightly closed when not in use.
Keep away from other sources of water but recognize that you are adding phosphorus pentoxide to 85% phosphoric acid (the other 15% is water) specifically to convert the solution water to phosphoric acid. 
As such, if you add it too quickly, the solution will steam and appear aggressive. 
If you spill powdered phosphorus pentoxide, it will quickly absorb water from the atmosphere leaving a puddle of phosphoric acid.

Description of first aid measures
General advice
Consult a physician. Show this safety data sheet to the doctor in attendance.Move out of dangerous area.

If inhaled
If breathed in, move person into fresh air. If not breathing, give artificial respiration. Consult a physician.

In case of skin contact
Take off contaminated clothing and shoes immediately. Wash off with soap and plenty of water. Take victim
immediately to hospital. Consult a physician.

In case of eye contact
Rinse thoroughly with plenty of water for at least 15 minutes and consult a physician.Continue rinsing eyes during transport to hospital.

If swallowed
Do NOT induce vomiting. Never give anything by mouth to an unconscious person. Rinse mouth with water. Consult a physician.

Most important symptoms and effects, both acute and delayed
The most important known symptoms and effects are described in the labelling (see section 2.2) and/or in section 11.

Also known as phosphorus anhydrous, phosphorus pentoxide (CAS: 1314-56-3) is a chemical compound that takes the form of a white crystalline solid. 
It is usually obtained by reacting phosphorus with excess dry air, followed by purification by sublimation.

Used as a chemical intermediate in the manufacture of flame retardants and pharmaceuticals, phosphorus pentoxide reacts vigorously or explosively with water to form phosphoric acids, which are irritating to the skin and mucous membranes.

Phosphorus pentoxide is often used in the pharmaceutical industry, but the compound is also used in coatings, dyes and other uses such as as a dehydrating agent.

Laboratory analysis of phosphorus pentoxide:
Expert in the field of chemical analysis, the Analytice company offers you to perform the determination of phosphorus pentoxide (CAS: 1314-56-3) in the air through a laboratory with ISO 17025 accreditation recognized by COFRAC (ILAC full member) for the phosphoric acid parameter in the working environment.

Water, magnesium oxide, chemically-active metals such as sodium & potassium, alkalis, amines [Note: Hydrolyzes in water (even in humid air) to form hydrochloric acid & phosphoric acid. Corrosive to metals.]

Stability:Stable under ordinary conditions of use and storage. Reacts violently with water to form phosphoric acid.
Hazardous Decomposition Products:Phosphorus oxides may form when heated to decomposition.
Hazardous Polymerization:Will not occur.
Incompatibilities:Ammonia, calcium oxide, chlorine trifluoride, hydrogen fluoride, oxygen difluoride, perchloric acid, perchloric acid and chloroform, potassium, propargyl alcohol, sodium, sodium carbonate, sodium hydroxide, water, and a mixture of water and organic material.
Conditions to Avoid:Moisture and incompatibles.

Whatever cannot be saved for recovery or recycling should be handled as hazardous waste and sent to a RCRA approved waste facility. 
Processing, use or contamination of this product may change the waste management options. State and local disposal regulations may differ from federal disposal regulations. 
Dispose of container and unused contents in accordance with federal, state and local requirements.

The XPS spectra of phosphorus pentoxide were collected with a VSW HA150, which is equipped with a monochromatic Al Kα x-radiation, a 16 channel multichannel detector, and an electrostatic hemispherical analyzer with a radius of 150 mm providing an instrument with exceptional capabilities. 
Monochromatic radiation provides a distinct clarity to the rich peak structure in the valence band region which shows significant differences from the phosphates. 
The valence band, survey, and P 2s, P 2p, O 1s, and C 1s core levels are reported.

(oxidant for the conversion of primary and secondary alcohols to aldehydes and ketones, respectively; avoids overoxidation to carboxylic acids; modified procedure gives very good yields with short reaction times at 0 °C with minimal formation of byproducts; inexpensive).

Form Supplied in: DMSO is a colorless liquid; widely available, including ‘anhydrous’ grades of DMSO packed under N2; P2O5 (more accurately P4O10) is a white crystalline solid; widely available.

Preparative Method: the active oxidant, formulated as Me2+:SO(P2O5)−, is generated in situ from the reaction of DMSO and P2O5 in the presence of the alcohol.

Purification: DMSO: distillation from CaH2 at 56–57 °C/5 mmHg2a or 83–85 °C/17 mmHg;2b storage over 3Å molecular sieves. P2O5: sublimation.

Phosphorus pentoxide is a powerful desiccant and dehydrating agent, reacting violently with water and releasing heat. 
Phosphorus pentoxide is used as a chemical intermediate and condensing agent for organic reactions. 
Phosphorus Pentoxide can be used in the manufacturer of phosphorus compounds including special phosphoric acid supported catalysts. 
In addition, phosphorus pentoxide can be used in the manufacturer of glass.

Phosphorus Pentoxide, Reagent, ACS is the anhydride of phosphoric acid and a powerful dehydrating and desiccant agent. 
Phosphorus pentoxide  is used extensively in organic synthesis as a dehydrating agent. 
As an ACS grade quality reagent, its chemical specifications are the de facto standards for chemicals used in many high-purity applications and typically designate the highest quality chemical available for laboratory use. 
Spectrum Chemical manufactured Reagent ACS grade products meet the toughest regulatory standards for quality and purity.

About this item
Phosphorus Pentoxide Chemical Label for Secondary Containers
Yellow and Black, 3" x 5" Pack of 25
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Laminated for Chemical and Solvent Resistance
OSHA Compliant GHS Safety Label

THE structure of two forms of phosphorus pentoxide was determined several years ago. 
Indications of the existence of a third form has been found in a study of the phase diagram by Hoeflake and Scheffer. 
Actually, in our former investigations we found occasionally a third kind of crystals, and we determined their cell dimensions and space group. 

However, we were not sure that these crystals were pure phosphorus pentoxide and not a reaction product with the glass wall, to which they adhere extremely firmly. 
Hill, Faust and Hendricks5 put the existence of a third form beyond doubt. 
They considered the modification as probably tetragonal (instead of orthorhombic, as found by us), as a result of optical investigation. 
According to their powder diagram data, however, it is certain that their crystals are identical with those described by us4.

Phosphorus along with calcium is an essential element in plant and animal growth, thus its principal source is organic ash (i.e. calcined cattle bones).
Phosphoric oxide is normally present in only trace amounts in ceramic materials.

Phosphorus pentoxide can act as a melter in middle to high fire, but its power-per-unit-added drops drastically beyond 5% additions.
Small amounts can produce colloidal opacity as in Chinese chun glazes. 
The depth of Sung glazes is attributed to phosphorus.

P2O5 is a glass network former like boric oxide and silicon dioxide. 
Phosphoric glass tends to show as a bluish flush in glazes. 
Phosphorus pentoxide does not enter the silica chain in the matrix. 
However, P2O5 by itself (with no SiO2 present in the matrix) is a glass former and the base of an entire class of glasses that can be doped with rare earths and metals for produce special purposes ranging from soluble medical implants to insoluble acid-resistance and even radiation resistance.

Phosphorus can vitrify porcelains without softening and is the key to translucency in bone china.
Phosphate ions are added to glaze frits as a color control agent during the melting of titania opacified frits.

P2O5 itself can crystallize in multiple forms. 
Phosphorus pentoxide  is known to influence the rate of nucleation and/or crystallization in Li2O and MgO low expansion glaze systems.
P2O5 combines with certain oxides of iron forms colorless compounds. 
Phosphorus pentoxide suggests that P2O5 could be used to allow the use of less pure materials in glazes and glass.

Phosphorite mineral Ca3(PO4)2 and Apatite 3Ca3(PO4)2 Ca(Cl,F)2 are the parent rocks of phosphate fertilizers. 
Phosphorus pentoxide  latter can thus be used to introduce phosphorus into glazes and frits.

Phosphorus Pentoxide is used as a strong drying and dehydrating agent such as the dehydration of amides to nitriles. 
Phosphorus pentoxide  is also used to manufacture optical glass, heat-insulating glass, pesticides and in the pharmaceutical industry.

Phosphorus pentoxide  objective of this research was to improve the fire-retardant properties of wood in one treatment using a phosphorus pentoxide–amine system. 
Phosphorus pentoxide and 16 amines including alkyl, halophenyl, and phenyl amines were compounded in N,N-dimethylformamide and the resulting solutions containing phosphoramides were reacted with wood. 
Phosphorus pentoxide  characteristics of phosphoramide-reacted wood were analyzed by FTIR, energy-dispersive X-ray analysis, and elemental analysis. 

Fire retardancy of phosphoramide-reacted woods was evaluated by DSC and thermogravimetric analysis (TGA). 
DSC demonstrated that the modification can lower the onset of an endotherm and decrease the heat of combustion and heat flow. 
TGA showed that most of the phosphoramide-reacted woods had higher char yields than that of wood impregnated with diammonium phosphate.