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| | METHYLPHOSPHONIC ACID Chemical Properties |
| 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) |
| | METHYLPHOSPHONIC ACID Usage And Synthesis |
| Preparation | In the preparation of methylphosphonic acid, triethyl phosphite is first subjected to the Michel-Albuzov reaction to generate a pentavalent phosphorus center: CH3Cl + P(OC2H5)3 → CH3PO(OC2H5)2 + C2H5Cl The resulting dialkylphosphonate reacts with trimethylchlorosilane, and then the siloxophosphonate is hydrolyzed to produce the desired product. CH3PO(OC2H5)2 + 2 Me3SiCl → CH3PO(OSiMe3)2 + 2 C2H5Cl CH3PO(OSiMe3)2 + 2H2O → CH3PO(OH)2 + 2 HOSiMe3 | | 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.] |
| | METHYLPHOSPHONIC ACID Preparation Products And Raw materials |
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