Tetrakis(hydroxymethyl)phosphonium chloride
| Tetrakis(hydroxymethyl)phosphonium chloride | |
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phosphonium_chloride.png) |
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Other names
Tetrahydroxymethylphosphonium chloride, THPC |
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| Identifiers | |
| CAS number | 124-64-1 |
| PubChem | 31298 |
| Properties | |
| Molecular formula | (HOCH2)4PCl |
| Molar mass | 190.56 g/mol |
| Appearance | cyrstalline |
| Density | 1.341 g/cm³ |
| Melting point |
150 °C (423 K) |
| Boiling point |
N/A |
| Solubility in water | N/A |
| Hazards | |
| R-phrases | R21 R25 R38 R41 R42/43 R51/53 |
| S-phrases | S22 S26 S36/37/39 S45 S60 S61 |
 (verify) (what is:  / ?)Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) |
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| Infobox references | |
Tetrakis(hydroxymethyl)phosphonium chloride (THPC) is an organophosphorus compound with the chemical formula [P(CH2OH)4]Cl. The cation P(CH2OH)4+ is four-coordinate, as is typical for phosphonium salts. THPC has applications as a precursor to fire-retardant materials.[1]
Contents |
Synthesis and reactions [edit]
THPC can be synthesized with high yield by treating phosphine with formaldehyde in the presence of hydrochloric acid.[1]
- PH3 + 4 H2C=O + HCl → [P(CH2OH)4]Cl
THPC is commonly used to prepare tris(hydroxymethyl)phosphine by treating it with aqueous sodium hydroxide.[2]
- [P(CH2OH)4]Cl + NaOH → P(CH2OH)3 + H2O + H2C=O + NaCl
Application in textiles [edit]
THPC has industrial importance in the production of crease-resistant and flame-retardant finishes on cotton textiles and other cellulosic fabrics.[3] A flame-retardant finish can be prepared from THPC by the Proban Process,[4] in which THPC is treated with urea. The urea condenses with the hydroxymethyl groups on THPC. The phosphonium structure is converted to phosphine oxide as the result of this reaction.[5]
- [P(CH2OH)4]Cl + NH2CONH2 → (HOCH2)2POCH2NHCONH2 + HCl + HCHO + H2 + H2O
This reaction proceeds rapidly, forming insoluble high molecular weight polymers. The resulting product is applied to the fabrics in a "pad-dry process." This treated material is then treated with ammonia and ammonia hydroxide to produce fibers that are flame-retardant.
THPC can condense with many other types of monomers in addition to urea. These monomers include amines, phenols, and polybasic acids and anhydrides.
Tris(hydroxymethyl)phosphine and its uses [edit]
Tris(hydroxymethyl)phosphine, which is derived from tetrakis(hydroxymethyl)phosphonium chloride, is an intermediate in the preparation of the water-soluble ligand 1,3,5-triaza-7-phosphaadamantane (PTA). This conversion is achieved by treating hexamethylenetetramine with formaldehyde and tris(hydroxymethyl)phosphine.[6]
Tris(hydroxymethyl)phosphine can also be used to synthesize the heterocycle, N-boc-3-pyrroline by ring-closing metathesis using Grubbs' catalyst (bis(tricyclohexylphosphine)benzylidineruthenium dichloride ). N-Boc-diallylamine is treated with Grubbs' catalyst, followed by tris(hydroxymethyl)phosphine. The carbon-carbon double bonds undergo ring closure, releasing ethylene gas, resulting in N-boc-3-pyrroline.[7] The hydroxymethyl groups on THPC undergo replacement reactions when THPC is treated with α,β-unsaturated nitrile, acid, amide, and epoxides. For example, base induces condensation between THPC and acrylamide with displacement of the hydroxymethyl groups. (Z = CONH2)
- [P(CH2OH)4]Cl + NaOH + 3CH2=CHZ → P(CH2CH2Z)3 + 4CH2O + H2O + NaCl
Similar reactions occur when THPC is treated with acrylic acid; only one hydroxymethyl group is displaced, however.[8]
References [edit]
- ^ a b Svara, Jürgen; Weferling, Norbert ; Hofmann, Thomas. Phosphorus Compounds, Organic. Ullmann's Encyclopedia of Industrial Chemistry. John Wiley & Sons, Inc, 2008 doi:10.1002/14356007.a19_545.pub2
- ^ M. Caporali, L. Gonsalvi, F. Zanobini, M. Peruzzini "Synthesis of the Water-Soluble Bidentate (P,N) Ligand PTN(Me)" Inorg. Syntheses, 2011, Vol. 35, p. 92–108. doi:10.1002/9780470651568.ch5
- ^ Weil, Edward D. ; Levchik, Sergei V. (2008). "Flame Retardants in Commercial Use or Development for Textiles". J. Fire Sci. 26 (3): 243–281. doi:10.1177/0734904108089485.
- ^ "Frequently asked questions: What is the PROBAN® process?". Rhodia Proban. Retrieved February 25, 2013.
- ^ Reeves, Wilson A.; Guthrie, John D. (1956). "Intermediate for Flame-Resistant Polymers-Reactions of Tetrakis(hydroxymethyl)phosphonium Chloride". Industrial Engineering Chemistry 48 (1): 64–67. doi:10.1021/ie50553a021.
- ^ Daigel, Donald J.; Decuir, Tara J.; Robertson, Jeffrey B.; Darensbourg, Donald J. (1998). "1,3,5-triaza-7phosphatricyclo[3.3.1.13.7]decane and derivatives". Inorg. Synth. Inorganic Syntheses 32: 40–42. doi:10.1002/9780470132630.ch6. ISBN 978-0-470-13263-0.
- ^ Ferguson, Marcelle L.; O’Leary, Daniel J.; Grubbs, Robert H. (2003), "Ring-Closing Metathesis Synthesis Of N-Boc-3-Pyrroline", Org. Synth. 80: 85
- ^ Vullo, W. J. (1966). "Hydroxymethyl Replacement Reactions of Tetrakis(hydroxymethyl)phosphonium Chloride". Ind. Eng. Chem. Prod. Res. Dev. 58 (4): 346–349. doi:10.1021/i360020a011.
