 | |
 Antimony, Sb Hydrogen, H | |
| Names | |
|---|---|
| IUPAC name Stibane | |
| Other names Antimony trihydride Hydrogen antimonide | |
| Identifiers | |
3D model (JSmol) | |
| ChEBI | |
| ChemSpider |
|
| ECHA InfoCard | 100.149.507 |
| EC Number |
|
| 795 | |
| RTECS number |
|
| UNII | |
| UN number | 2676 |
| |
| |
| Properties | |
| SbH3 | |
| Molar mass | 124.784 g/mol |
| Appearance | Colourless gas |
| Odor | unpleasant, likehydrogen sulfide |
| Density | 5.48 g/L, gas |
| Melting point | −88 °C (−126 °F; 185 K) |
| Boiling point | −17 °C (1 °F; 256 K) |
| slightly soluble | |
| Solubility in ethanol | soluble[1] |
| Vapor pressure | >1 atm (20°C)[2] |
| Conjugate acid | Stibonium |
| Structure | |
| Trigonal pyramidal | |
| Hazards | |
| Occupational safety and health (OHS/OSH): | |
Main hazards | Extremely toxic, flammable and highly reactive |
| GHS labelling: | |
   | |
| Danger | |
| H220,H330,H370 | |
| P210,P260,P264,P270,P307+P311,P321,P377,P381,P403,P405,P501 | |
| NFPA 704 (fire diamond) | |
| Flash point | Flammable gas |
| Lethal dose or concentration (LD, LC): | |
LCLo (lowest published) | 100 ppm (mouse, 1 hr) 92 ppm (guinea pig, 1 hr) 40 ppm (dog, 1 hr)[3] |
| NIOSH (US health exposure limits): | |
PEL (Permissible) | TWA 0.1 ppm (0.5 mg/m3)[2] |
REL (Recommended) | TWA 0.1 ppm (0.5 mg/m3)[2] |
IDLH (Immediate danger) | 5 ppm[2] |
| Related compounds | |
Related compounds | Ammonia Phosphine Arsine Bismuthine Triphenylstibine |
Except where otherwise noted, data are given for materials in theirstandard state (at 25 °C [77 °F], 100 kPa). | |
Stibine (IUPAC name:stibane) is achemical compound with the formulaSbH3. Apnictogen hydride, this colourless, highly toxic gas is the principalcovalent hydride ofantimony, and a heavy analogue ofammonia. The molecule is pyramidal with H–Sb–H angles of 91.7° and Sb–H distances of 170.7pm (1.707Å). The smell of this compound from usual sources (like from reduction of antimony compounds) is reminiscent ofarsine, i.e. garlic-like.
SbH3 is generally prepared by the reaction of Sb3+ sources with H− equivalents:[4]
Alternatively, sources of Sb3− react with protonic reagents (even water) to also produce this unstable gas:
The chemical properties of SbH3 resemble those forAsH3.[5] Typical for a heavy hydride (e.g. AsH3, H2Te, SnH4), SbH3 is unstable with respect to its elements. The gas decomposes slowly at room temperature but rapidly at 200 °C:
The decomposition isautocatalytic and can be explosive.
SbH3 is readilyoxidized by O2 or even air:
SbH3 exhibits no basicity, but it can be deprotonated:
The saltNaSbH2 is called sodium stibinide, and contains the stibinide anionSbH−2.
Stibine is used in thesemiconductor industry todope silicon with small quantities ofantimony via the process ofchemical vapour deposition (CVD). It has also been used as a silicon dopant in epitaxial layers. Reports claim the use of SbH3 as afumigant but its instability and awkward preparation contrast with the more conventional fumigantphosphine.
As stibine (SbH3) is similar toarsine (AsH3); it is also detected by theMarsh test. This sensitive test detects arsine generated in the presence ofarsenic.[5] This procedure, developed circa 1836 byJames Marsh, treats a sample with arsenic-freezinc and dilutesulfuric acid: if the sample contains arsenic, gaseous arsine will form. The gas is swept into a glass tube and decomposed by means of heating around 250 – 300 °C. The presence of arsenic is indicated by formation of a deposit in the heated part of the equipment. The formation of a black mirror deposit in the cool part of the equipment indicates the presence ofantimony.
In 1837Lewis Thomson andPfaff independently discovered stibine. It took some time before the properties of the toxic gas could be determined, partly because a suitable synthesis was not available. In 1876 Francis Jones tested several synthesis methods,[6] but it was not before 1901 whenAlfred Stock determined most of the properties of stibine.[7][8]
SbH3 is an unstable flammable gas. It is highly toxic, with anLC50 of 100 ppm in mice.
The toxicity of stibine is distinct from that of otherantimony compounds, but similar to that ofarsine.[9] Stibine binds to thehaemoglobin of red blood cells, causing them to be destroyed by the body. Most cases of stibine poisoning have been accompanied by arsine poisoning, although animal studies indicate that their toxicities are equivalent. The first signs of exposure, which can take several hours to become apparent, areheadaches,vertigo, andnausea, followed by the symptoms ofhemolytic anemia (high levels of unconjugatedbilirubin),hemoglobinuria, andnephropathy.
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