Arsinide
Chemical compound
From Wikipedia, the free encyclopedia
An arsinide, arsanide, dihydridoarsenate(1−) or arsanyl compound is a chemical derivative of arsine, where one hydrogen atom is replaced with a metal or cation. The arsinide ion has formula AsH−2. It can be considered as a ligand with name arsenido or arsanido. Few chemists study arsanyl compounds, as they are both toxic and unstable.[1] The IUPAC names are arsanide and dihydridoarsenate(1−). For the ligand the name is arsanido. The neutral −AsH2 group is termed arsanyl.
| Names | |
|---|---|
| IUPAC name
Arsanide | |
Other names
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| Identifiers | |
3D model (JSmol) |
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| ChEBI | |
| ChemSpider | |
| 217243 | |
| |
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| Properties | |
| AsH2− | |
| Molar mass | 76.938 g·mol−1 |
| 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).
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Formation
Alkali metal arsinides can form by bubbling arsine through a liquid ammonia solution of alkali metal such as sodium, potassium or alkaline earth metal such as calcium.[2]
Arsinides are also formed when arsine reacts with thin layers of alkali metals.[3]
The arsine may reduce some compounds to metals, so for example an attempt to make an indium arsinide results in metallic indium.[1]
Reactions
When heated, metal hydrogen arsinide and metal dihydrogen arsinide compounds lose hydrogen to become a metal arsenide:
- NaAsH2 → NaAs + H2[3]
With lithium dihydrogen arsinide LiAsH2, it can also lose arsine AsH3 to become dilithium hydrogen arsinide Li2AsH:
- 2 LiAsH2 → Li2AsH + AsH3[3]
These reactions take place even at room temperature, and result in a discolouration of the original chemical.[3]
Sodium dihydrogen arsinide NaAsH2 reacts with alkyl halides RX (where X = F, Cl, Br, I, and R is alkyl) to make dialkylarsine AsHR2. Potassium dihydrogen arsinide KAsH2 reacts with alkyl halides to make trialkylarsine AsR3.[4]
Sodium dihydrogen arsinide NaAsH2 reacts with diethyl carbonate (CH3CH2O)2CO to yield the 2-arsaethynolate [OCAs]− ion, (analogous with cyanate [OCN]− ion) which can be crystallised with the sodium ion Na+ and 18-crown-6.[5]
Arsinides react with water to yield arsine AsH3:
- KAsH2 + H2O → KOH + AsH3[6]
Potassium dihydrogen arsinide KAsH2 reacts with halobenzenes C6H5X, where X = Cl, Br, I (chlorobenzene C6H5Cl, bromobenzene C6H5Br, iodobenzene C6H5I) to produce benzene C6H6, tetraphenyldiarsine (C6H5)2As−As(C6H5)2 and triphenylarsine As(C6H5)3.[7]
Potassium dihydrogen arsinide KAsH2 reacts with a silyl halide, e.g. chlorosilane SiH3Cl, producing trisilylarsine.[8]
Potassium dihydrogen arsinide KAsH2 reacts with H2As−BH2·N(CH3)3 and a crown ether resulting in [K(C12H24O6)]+[H2As−BH2−AsH2]−.[9]
List
| Formula | Name | Crystal system | Space group | Unit cell (Å) | Volume | Density | Comment | ref |
|---|---|---|---|---|---|---|---|---|
| LiAsH2 | Lithium arsanide | [3] | ||||||
| Li2AsH | Dilithium arsanide | decomposition at 0°C | [3] | |||||
| LiAsH2·2NH3 | [3] | |||||||
| LiAsH2·4NH3 | [3] | |||||||
| NaAsH2 | Sodium arsanide | white; decomposition at room temperature | [2] | |||||
| Na2AsH | Disodium arsanide | [3] | ||||||
| NaAsH2·2NH3 | [3] | |||||||
| NaAsH2·4NH3 | [3] | |||||||
| Li+[Al(AsH2)4]− | Lithium tetraarsanidoaluminate | [1] | ||||||
| (Dipp2Nacnac)Al(AsH2)2 Dipp2Nacnac=HC[C(Me)N(2,6-iPr2C6H3)]2 | [1] | |||||||
| IDipp⋅AlH2AsH2 IDipp=1,3-bis(2,6-diisopropylphenyl)imidazolin-2-ylidene) | monoclinic | I2/a | colourless | [10] | ||||
| IDipp⋅AlH(AsH2)2 | monoclinic | I2/a | a 18.3591 b 9.0485 c 34.4864 β 91.580° | [10] | ||||
| KAsH2 | Potassium arsanide | stable to 80°C; decomposition at 90°C | [2] | |||||
| Ca(AsH2)2 | Calcium arsanide | [2] | ||||||
| (Dipp2Nacnac)Ga(AsH2)2 | [1] | |||||||
| IDipp⋅GaH2AsH2 | monoclinic | I2/a | colourless | [10] | ||||
| IDipp⋅GaH(AsH2)2 | monoclinic | I2/a | a 18.465 b 9.1493 c 34.661 β 91.509° | [10] | ||||
| Th(TrenTRIPS)AsH2 | Th-As 3.065 Å | [11] | ||||||
| U(TrenTRIPS)AsH2 | U-As 3.004 Å | [11] | ||||||
Related
The hydrogen atoms in the arsinide anion may be substituted by organic or other groups which can then also produce ions, for example by methyl −CH3, like in potassium methyl arsinide (K+CH3AsH−),[12] or by trimethylsilyl −Si(CH3)3.[1] The doubly bonded ligand =AsH (or AsH2−) is called arsinidene.[11]