Phosphine
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| Names | |||
|---|---|---|---|
| IUPAC name
Phosphane
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| Other names
Hydrogen phosphide
Phosphamine Phosphorus trihydride Phosphorated hydrogen | |||
| Identifiers | |||
CAS Number
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3D model (JSmol)
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| ChEBI | |||
| ChemSpider | |||
| ECHA InfoCard | 100.029.328 | ||
| EC Number |
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Gmelin Reference
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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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InChI
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SMILES
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| Properties | |||
Chemical formula
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PH3 | ||
| Molar mass | 33.99758 g/mol | ||
| Appearance | Colourless gas | ||
| Odor | odorless as pure compound; fish-like or garlic-like commercially[1] | ||
| 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) | ||
Solubility in water
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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)[1] | ||
| Conjugate acid | Phosphonium (PH+4) | ||
Refractive index (nD)
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2.144 | ||
| Viscosity | 1.1×10−5 Pa⋅s | ||
| Structure | |||
Molecular shape
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Trigonal pyramidal | ||
Dipole moment
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0.58 D | ||
| Thermochemistry | |||
Heat capacity (C)
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37 J/mol⋅K | ||
Std molar
entropy (S⦵298) |
210 J/mol⋅K[2] | ||
Std enthalpy of
formation (ΔfH⦵298) |
5 kJ/mol[2] | ||
Gibbs free energy (ΔfG⦵)
|
13 kJ/mol | ||
| Hazards | |||
| GHS labelling: | |||
Pictograms
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| NFPA 704 (fire diamond) | |||
| Flash point | Flammable gas | ||
Autoignition
temperature |
38 °C (100 °F; 311 K) (see text) | ||
| Explosive limits | 1.79–98%[1] | ||
| Lethal dose or concentration (LD, LC): | |||
LD50 (median dose)
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3.03 mg/kg (rat, oral) | ||
LC50 (median concentration)
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11 ppm (rat, 4 hr)[3] | ||
LCLo (lowest published)
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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)[3] | ||
| NIOSH (US health exposure limits): | |||
PEL (Permissible)
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TWA 0.3 ppm (0.4 mg/m3)[1] | ||
REL (Recommended)
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TWA 0.3 ppm (0.4 mg/m3), ST 1 ppm (1 mg/m3)[1] | ||
IDLH (Immediate danger)
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50 ppm[1] | ||
| 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
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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.[4] They have the general formula PH3−nRn. Phosphanes are saturated phosphorus hydrides of the form PnHn+2, such as triphosphane.[5] Phosphine (PH3) is the smallest of the phosphines and the smallest of the phosphanes.
- ^ a b c d e f NIOSH Pocket Guide to Chemical Hazards. "#0505". National Institute for Occupational Safety and Health (NIOSH).
- ^ a b Zumdahl, Steven S. (2009). Chemical Principles (6th ed.). Houghton Mifflin. p. A22. ISBN 978-0-618-94690-7.
- ^ a b "Phosphine". Immediately Dangerous to Life or Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).
- ^ IUPAC, Compendium of Chemical Terminology, 5th ed. (the "Gold Book") (2025). Online version: (2006–) "phosphines". doi:10.1351/goldbook.P04553
- ^ IUPAC, Compendium of Chemical Terminology, 5th ed. (the "Gold Book") (2025). Online version: (2006–) "phosphanes". doi:10.1351/goldbook.P04548