Silver tetrafluoroborate
Chemical compound
From Wikipedia, the free encyclopedia
Silver tetrafluoroborate is an inorganic compound with the molecular formula AgBF4. It is a white solid (although commercial samples often are gray) that dissolves in polar organic solvents as well as water.[4]
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| Names | |
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| IUPAC name
Silver tetrafluoridoborate(1–) | |
Other names
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| Identifiers | |
3D model (JSmol) |
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| ChemSpider | |
| ECHA InfoCard | 100.034.491 |
| EC Number |
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PubChem CID |
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| RTECS number |
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| UN number | 3260 |
CompTox Dashboard (EPA) |
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| Properties | |
| AgBF4 | |
| Molar mass | 194.67 g·mol−1 |
| Appearance | Beige powder |
| Density | 4.61 g/cm3 |
| Melting point | 71.5 °C (160.7 °F; 344.6 K) (monohydrate) |
| soluble | |
| Band gap | 3.16 eV |
| Structure[1] | |
| Orthorhombic | |
| Pnma | |
| mmm | |
a = 8.089±0.008 Å, b = 5.312±0.006 Å, c = 6.752±0.009 Å α = 90°, β = 90°, γ = 90° | |
Lattice volume (V) |
290.1 Å3 |
Formula units (Z) |
4 |
| Hazards | |
| GHS labelling:[2] | |
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| Danger | |
| H314 | |
| P260, P264, P280, P301+P330+P331, P303+P361+P353, P304+P340+P310, P305+P351+P338+P310, P363, P405, P501 | |
| NFPA 704 (fire diamond) | |
Threshold limit value (TLV) |
2.5 mg/m3[3] (TWA) |
| NIOSH (US health exposure limits):[3] | |
PEL (Permissible) |
2.5 mg/m3 (TWA) |
REL (Recommended) |
2.5 mg/m3 (TWA) |
IDLH (Immediate danger) |
250 mg/m3 |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Structure
According to X-ray crystallography, the solid compound consists of Ag+ centers bound to four fluoride sites of the BF−4.[1]
Preparation
Silver tetrafluoroborate can be prepared by several methods. A simple route entails dissolving silver carbonate (Ag2CO3) in aqueous tetrafluoroboric acid (HBF4).[5] It can also be produced by treating silver(I) fluoride (AgF) with boron trifluoride in nitromethane (CH3NO2) solution. The reaction between boron trifluoride (BF3) and a benzene suspension of silver oxide (Ag2O) is yet another route, one that exploits the solubility of the compound in benzene. This method however affords silver fulminate (AgCNO), a sensitive explosive.[6]
Laboratory uses
In the inorganic and organometallic chemistry laboratory, silver tetrafluoroborate, sometimes referred to "silver BF-4", is a used as a reagent to remove halide ligands and to oxidize electron-rich complexes. In dichloromethane, silver tetrafluoroborate is a moderately strong oxidant.[7] Similar to silver hexafluorophosphate (AgPF6), it is commonly used to replace halide anions or ligands with the weakly coordinating tetrafluoroborate anions. The abstraction of the halide is driven by the precipitation of the corresponding silver halide.
