| IUPAC name
| Other names
|Molar mass||104.85 g/mol|
|Appearance||White crystalline solid|
|Density||1.871 g/cm3 (15 °C)|
|Melting point||220–230 °C (428–446 °F; 493–503 K) (sublimes)|
| 10.85 g/100 ml (-2.7 °C)|
5.26 g/100 ml (-1.5 °C)
3.09 g/100 ml (-1.0 °C)
12.20 g/100 ml (0 °C)
25.0 g/100 ml (16 °C)
25.83 g/100 ml (25 °C)
44.09 g/100 ml (50 °C)
67.50 g/100 ml (75 °C)
98.93 g/100 ml (100 °C)
113.7 g/100 ml (108.5 °C)
|Solubility||Soluble in aq. NH3|
|Solubility in hydrogen fluoride||20% (0 °C)|
|Vapor pressure||~0 mmHg|
|Safety data sheet||Sigma-Aldrich|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Ammonium tetrafluoborate (NH4BF4) is a chemical compound, a primary source of the BF4− cation.
The BF4− anion is less nucleophilic and basic (and therefore more weakly coordinating) than nitrates, halides or even triflates. Thus, when using salts of BF4−, one can usually assume that the cation is the reactive agent and this tetrahedral anion is inert.
When heated to decomposition it emits very toxic fumes of hydrogen fluoride, nitrogen oxides and ammonia.
Ammonium tetrafluoborate is a colorless crystalline solid, soluble in water.
It is sold by chemical suppliers.
- H3BO3 + 4 HF → HBF4 + 3 H2O
- HBF4 + NH4HCO3 → NH4BF4 + H2O + CO2
- Preparation of arenediazonium tetrafluoroborates
- Inversion of chiral amines
- Dealumination of zeolites
- Isolate highly electrophilic cations
- Electrolyte useful for synthetic electrochemistry
- Source of fluoride
Ammonium tetrafluoroborate is toxic if ingested, as both boron and fluorides are harmful.
It is mentioned that it's corrosive to aluminium.
In closed bottles.
Best to try and recycle it.
- Roe, A., Org. React. 1949, 5, 193
- Moss, R. A.; Schueler, P. E.; Lee, T. B. K., Tetrahedron Lett. 1973, 2509. (b) Moss, R. A., J. Org. Chem. 1966, 31, 1082
- Association of American Railroads. Emergency Handling of Hazardous Materials in Surface Transportation. Washington, D.C.: Assoc. of American Railroads, Hazardous Materials Systems (BOE), 1987., p. 34