Silver tetrafluoroborate
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| Names | |
|---|---|
| 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] | |
 | |
| 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).
Infobox references | |
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]
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.
References
- 1 2 Goreshnik, Evgeny; Mazej, Zoran (October 2005). "X-ray single crystal structure and vibrational spectra of AgBF4". Solid State Sciences. 7 (10): 1225–1229. doi:10.1016/j.solidstatesciences.2005.06.007.
- ↑ Sigma-Aldrich Co., Silver tetrafluoroborate.
- 1 2 3 "Silver tetrafluoroborate - SDS". documents.thermofisher.com. Revision Number 7. ThermoFisher Scientific. 19 December 2025 [7 March 2012]. Retrieved 31 May 2026.
- ↑ Wistrand, Lars-G.; Kerekes, Angela D.; Sannigrahi, Mousumi (2005). "Silver Tetrafluoroborate". Encyclopedia of Reagents for Organic Synthesis. doi:10.1002/047084289X.rs028.pub2. ISBN 0-471-93623-5.
- ↑ Chalker, Justin M.; Thompson, Amber L.; Davis, Benjamin (2010). "Safe and Scalable Preparation of Barluenga's Reagent". Organic Syntheses. 87: 288. doi:10.15227/orgsyn.087.0288.
- ↑ Lemal, D. M; Fry, A. J. (1961-01-01). "The preparation of silver fluoroborate: a warning". Tetrahedron Letters. 2 (21): 775–6. doi:10.1016/S0040-4039(01)99266-4. ISSN 0040-4039.
- ↑ N. G. Connelly, W. E. Geiger (1996). "Chemical Redox Agents for Organometallic Chemistry". Chemical Reviews. 96 (2): 877–910. doi:10.1021/cr940053x. PMID 11848774.