Phosphine
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| Names | |||
|---|---|---|---|
| IUPAC name
Phosphane | |||
| Other names
Hydrogen phosphide Phosphamine Phosphorus trihydride Phosphorated hydrogen | |||
| Identifiers | |||
3D model (JSmol) |
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| ChEBI | |||
| ChemSpider | |||
| ECHA InfoCard | 100.029.328 | ||
| EC Number |
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| 287 | |||
PubChem CID |
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| RTECS number |
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| UNII | |||
| UN number | 2199 | ||
CompTox Dashboard (EPA) |
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| Properties | |||
| PH3 | |||
| Molar mass | 33.99758 g/mol | ||
| Appearance | Colourless gas | ||
| Odor | odorless as pure compound; fish-like or garlic-like commercially | ||
| Density | 1.379 g/L, gas (25 °C) | ||
| Melting point | −132.8 °C (−207.0 °F; 140.3 K) | ||
| Boiling point | −87.7 °C (−125.9 °F; 185.5 K) | ||
| 31.2 mg/100 ml (17 °C) | |||
| Solubility | Soluble in alcohol, ether, CS2 slightly soluble in benzene, chloroform, ethanol | ||
| Vapor pressure | 41.3 atm (20 °C) | ||
| Conjugate acid | Phosphonium (chemical formula PH+ 4) | ||
Refractive index (nD) |
2.144 | ||
| Viscosity | 1.1×10−5 Pa⋅s | ||
| Structure | |||
| Trigonal pyramidal | |||
| 0.58 D | |||
| Thermochemistry | |||
Heat capacity (C) |
37 J/mol⋅K | ||
Std molar entropy (S⦵298) |
210 J/mol⋅K | ||
Std enthalpy of formation (ΔfH⦵298) |
5 kJ/mol | ||
Gibbs free energy (ΔfG⦵) |
13 kJ/mol | ||
| Hazards | |||
| GHS labelling: | |||
| NFPA 704 (fire diamond) | |||
| Flash point | Flammable gas | ||
| 38 °C (100 °F; 311 K) (see text) | |||
| Explosive limits | 1.79–98% | ||
| Lethal dose or concentration (LD, LC): | |||
LD50 (median dose) |
3.03 mg/kg (rat, oral) | ||
LC50 (median concentration) |
11 ppm (rat, 4 hr) | ||
LCLo (lowest published) |
1000 ppm (mammal, 5 min) 270 ppm (mouse, 2 hr) 100 ppm (guinea pig, 4 hr) 50 ppm (cat, 2 hr) 2500 ppm (rabbit, 20 min) 1000 ppm (human, 5 min) | ||
| NIOSH (US health exposure limits): | |||
PEL (Permissible) |
TWA 0.3 ppm (0.4 mg/m3) | ||
REL (Recommended) |
TWA 0.3 ppm (0.4 mg/m3), ST 1 ppm (1 mg/m3) | ||
IDLH (Immediate danger) |
50 ppm | ||
| Safety data sheet (SDS) | ICSC 0694 | ||
| Related compounds | |||
Other cations |
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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 | |||
Phosphine (IUPAC name: phosphane) is a colorless, flammable, highly toxic compound with the chemical formula PH3, classed as a pnictogen hydride. Pure phosphine is odorless, but technical grade samples have a highly unpleasant odor like rotting fish, due to the presence of substituted phosphine and diphosphane (P2H4). With traces of P2H4 present, PH3 is spontaneously flammable in air (pyrophoric), burning with a luminous flame. Phosphine is a highly toxic respiratory poison, and is immediately dangerous to life or health at 50 ppm. Phosphine has a trigonal pyramidal structure.
Phosphines are compounds that include PH3 and the organophosphines, which are derived from PH3 by substituting one or more hydrogen atoms with organic groups. They have the general formula PH3−nRn. Phosphanes are saturated phosphorus hydrides of the form PnHn+2, such as triphosphane. Phosphine, PH3, is the smallest of the phosphines and the smallest of the phosphanes.