Trimethylphosphine oxide
| Names | |
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| IUPAC name
Dimethylphosphorylmethane[1]
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Other names
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| Identifiers | |
3D model (JSmol)
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| Abbreviations | TMPO |
| ChEMBL | |
| ChemSpider | |
| ECHA InfoCard | 100.010.577 |
| EC Number |
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PubChem CID
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| UNII | |
CompTox Dashboard (EPA)
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| Properties | |
| (CH3)3PO | |
| Molar mass | 92.078 g·mol−1 |
| Appearance | White crystalline solid[2] |
| Odor | Odorless[2] |
| Density | 0.9 g/cm3[3] |
| Melting point | 140–141 °C (284–286 °F; 413–414 K)[2] |
| Boiling point | 193.7 °C (380.7 °F; 466.8 K)[3] |
| Soluble | |
| Solubility | Soluble in polar organic solvents.[3] |
| Structure | |
| Tetrahedral at P | |
| Hazards | |
| Occupational safety and health (OHS/OSH): | |
Main hazards
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Serious eye irritation and damage |
| GHS labelling: | |
| Warning | |
| H302, H315, H319, H335 | |
| P261, P264, P264+P265, P270, P271, P280, P301+P317, P302+P352, P304+P340, P305+P351+P338, P319, P321, P330, P332+P317, P337+P317, P362+P364, P403+P233, P405, P501 | |
| NFPA 704 (fire diamond) | |
| Flash point | 71 °C (160 °F)[3] |
| Related compounds | |
Related compounds
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Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references
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Trimethylphosphine oxide is an organophosphorus compound with the chemical formula (CH3)3PO. It forms highly hygroscopic, white, needle-shaped crystals.[4] It forms a dihydrate (CH3)3PO·2H2O.[5]
Synthesis
Trimethylphosphine oxide can be obtained by reaction between phosphoryl chloride and a Grignard reagent methylmagnesium chloride.[6][7]
- POCl3 + 3 CH3MgCl → (CH3)3PO + 3 MgCl2
Trimethylphosphine is easily oxidized by oxygen to trimethylphosphine oxide.[8]
Structure
Trimethylphosphine oxide molecule is tetrahedral at the phosphorus atom. It is a resonance between these two structures:[9]
- (CH3)3P+−O− ↔ (CH3)3P=O
The distances between atoms are as follows:[4]
The angles between atoms are as follows:[4]
- ∠C-P-O 112.3°
- ∠C-P-C 106.0°
- ∠P-C-H 109°
References
- ^ "Trimethylphosphine oxide". pubchem.ncbi.nlm.nih.gov.
- ^ a b c "Safety Data Sheet". ThermoFisher Scientific. 24 February 2024.
- ^ a b c d "TRIMETHYLPHOSPHINE OXIDE - Safety Data Sheet". www.chemicalbook.com.
- ^ a b c Wang, Hagbarth K. (1965). "The Molecular Structure of Trimethylphosphine Oxide" (PDF). Acta Chemica Scandinavica. 19: 879–882. doi:10.3891/acta.chem.scand.19-0879 (inactive 18 February 2026).
{{cite journal}}: CS1 maint: DOI inactive as of February 2026 (link) - ^ Urlep, M.; Cerkovnik, J.; Lozinšek, M. (2023). "Trimethylphosphine oxide dihydrate". IUCrData. 8 (Pt 4) x230314. Bibcode:2023IUCrD...830314U. doi:10.1107/S2414314623003140. PMC 10162029. PMID 37151205.
- ^ "TRIMETHYLPHOSPHINE OXIDE synthesis - chemicalbook". www.chemicalbook.com.
- ^ "Method for synthesizing trimethylphosphine oxide". 2015.
- ^ Schmidbaur, H. (January 17, 1978). "Trimethylphosphonium Methylide (Trimethyl Methylenephosphorane)". Inorganic Syntheses. Vol. 18. John Wiley & Sons, Ltd. pp. 135–140. doi:10.1002/9780470132494.ch23. ISBN 978-0-471-03393-6 – via Wiley Online Library.
- ^ Albright, Thomas A.; Freeman, Walter J.; Schweizer, Edward E. (November 1, 1975). "Nuclear magnetic resonance studies. IV. Carbon and phosphorus nuclear magnetic resonance of phosphine oxides and related compounds". The Journal of Organic Chemistry. 40 (23): 3437–3441. doi:10.1021/jo00911a030 – via ACS Publications.