Trimethylphosphine
From Wikipedia, the free encyclopedia
| Trimethylphosphine | |
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| IUPAC name | Trimethylphosphine |
| Other names | trimethylphosphane |
| Identifiers | |
| CAS number | [594-09-2] |
| Properties | |
| Molecular formula | C3H9P |
| Molar mass | 76.07 g/mol |
| Appearance | Colorless liquid, Pyrophoric |
| Density | 0.735 g/cm3 liquid |
| Melting point |
-86 °C |
| Boiling point |
38-39 °C |
| Solubility in water | low |
| Solubility in other solvents | most organic solvents |
| Structure | |
| Coordination geometry |
Trigonal pyramidal |
| Dipole moment | 1.19 Debye |
| Hazards | |
| Main hazards | toxic |
| R-phrases | 11-36/37/38 |
| S-phrases | 9-16-26-36/37/39 |
| Related compounds | |
| Related compounds | NMe3 PH3 PPh3 |
| Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references |
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Trimethylphosphine is the chemical compound with the formula P(CH3)3, commonly abbreviated PMe3. This colorless liquid has a strongly unpleasant odour, which characteristic of alkylphosphines. It is a pyramidal molecule with C3v symmetry, similar to ammonia (NH3) and phosphine (PH3). As a ligand, its cone angle is 118°.[1]
PMe3 is prepared using Grignard reagents:[2]
- 3 CH3MgBr + P(OC6H5)3 → P(CH3)3 + 3 MgBrOC6H5
The synthesis is conducted in a dibutyl ether, from which the more volatile PMe3 can be distilled.
[edit] Coordination chemistry
Trimethylphosphine is a highly basic ligand that forms complexes with most metals. The synthesis of an illustrative example is shown:
- PMe3 + Fe(CO)5 → Fe(CO)4PMe3 + CO
Its complex with silver iodide, AgI(PMe3) is a weighable, air stable compound that releases PMe3 upon heating.
[edit] Safety
PMe3 is potentially pyrophoric, as well as toxic.
[edit] References
- ^ G. L. Miessler and D. A. Tarr “Inorganic Chemistry” 3rd Ed, Pearson/Prentice Hall publisher, ISBN 0-13-035471-6.
- ^ Leutkens, Jr., M. L.; Sattelberger, A. P.; Murray, H. H.; Basil, J. D.; Fackler, Jr., J. P. (1990). "Trimethylphosphine". Inorganic Syntheses 28: 305–310. doi:.
