METHYLPHOSPHONIC ACID Property

Melting point:

105-107 °C(lit.)

Boiling point:

265.2±23.0 °C(Predicted)

Density 

1.495±0.06 g/cm3(Predicted)

vapor pressure 

0Pa at 20℃

storage temp. 

-20°C

solubility 

H2O: soluble2.88 g in 30 mL, clear, colorless

form 

Crystalline Powder

pka

pK1:2.38;pK2:7.74 (25°C)

color 

White to off-white

PH

0.9-1.4

Water Solubility 

Soluble in water and alcohol.

Sensitive 

Hygroscopic

λmax

λ: 260 nm Amax: ≤0.05
λ: 280 nm Amax: ≤0.04

BRN 

1739372

Stability:

Stable. Incompatible with strong oxidizing agents, strong bases.

LogP

-1.556 at 20℃

EPA Substance Registry System

Phosphonic acid, P-methyl- (993-13-5)

Safety

Hazard Codes 

C,T,F

Risk Statements 

22-34-39/23/24/25-23/24/25-11

Safety Statements 

26-36/37/39-45-36/37-16-7

RIDADR 

UN 3261 8/PG 2

WGK Germany 

3

F 

10

HazardClass 

8

PackingGroup 

II

HS Code 

29310099

Hazardous Substances Data

993-13-5(Hazardous Substances Data)

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Danger

Hazard statements

H314Causes severe skin burns and eye damage

Precautionary statements

P260Do not breathe dust/fume/gas/mist/vapours/spray.

P280Wear protective gloves/protective clothing/eye protection/face protection.

P303+P361+P353IF ON SKIN (or hair): Remove/Take off Immediately all contaminated clothing. Rinse SKIN with water/shower.

P305+P351+P338IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continuerinsing.

METHYLPHOSPHONIC ACID Chemical Properties,Usage,Production

Chemical Properties

white crystals or flakes

Uses

Organic synthesis.

Uses

Methylphosphonic acid is used to produce methyl-phosphonic acid dichloride by chlorination.

Definition

ChEBI: Methylphosphonic acid is a one-carbon compound that is phosphonic acid in which the hydrogen attached to the phosphorus is substituted by a methyl group. It is a one-carbon compound and a member of phosphonic acids. It is functionally related to a phosphonic acid. It is a conjugate acid of a methylphosphonate(1-).

Application

Methylphosphonic acid is used in the production of lubricant additives and for treating textiles.

Flammability and Explosibility

Not classified

Purification Methods

Methylphosphonic acid [993-13-5] M 96.0, m 104-106o, 105-107o, 108o, pK 1 2.12, pK 2 7.29. If it tests for Cl-, then add H2O and evaporate to dryness, repeat several times till free from Cl-. The residue solidifies to a wax-like solid. Alternatively, dissolve the acid in the minimum volume of H2O, add charcoal, warm, filter and evaporate to dryness in a vacuum over P2O5. [Kosolapoff J Am Chem Soc 75 3379 1953.] The di-Na salt is prepared from 24g of acid in 50mL of dry EtOH, and a solution of 23g Na dissolved in 400mL EtOH is added. A white precipitate is formed, but the mixture is refluxed for 30minutes to complete the reaction. Filter off the solid and recrystallise it from 50% EtOH. Dry the crystals in a vacuum desiccator. [Thompson J Chem Soc 3292 1952, Beilstein 4 IV 3498.]