Sodium tetrafluoroborate Property

Melting point:

384 °C

Density 

2.47 g/mL at 25 °C(lit.)

storage temp. 

Inert atmosphere,Room Temperature

solubility 

water: soluble(lit.)

form 

Powder, Crystals or Needles

Specific Gravity

2.47

color 

White to yellow to beige to brown

Water Solubility 

108 g/100 mL (26 ºC)

Sensitive 

Hygroscopic

Merck 

14,8617

Exposure limits

ACGIH: TWA 2.5 mg/m3
NIOSH: IDLH 250 mg/m3; TWA 2.5 mg/m3

Stability:

Moisture sensitive; do not store in glass (though the completely dry material does not etch glass). Incompatible with strong oxidizing agents.

CAS DataBase Reference

13755-29-8(CAS DataBase Reference)

EPA Substance Registry System

Borate(1-), tetrafluoro-, sodium (13755-29-8)

Safety

Hazard Codes 

C,Xi

Risk Statements 

34

Safety Statements 

45-36/37/39-25-26

RIDADR 

3260

WGK Germany 

1

RTECS 

ED2975000

F 

21

Hazard Note 

Irritant

TSCA 

Yes

HS Code 

2826 90 80

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Danger

Hazard statements

H314Causes severe skin burns and eye damage

Precautionary statements

P260Do not breathe dust/fume/gas/mist/vapours/spray.

P280Wear protective gloves/protective clothing/eye protection/face protection.

P303+P361+P353IF ON SKIN (or hair): Remove/Take off Immediately all contaminated clothing. Rinse SKIN with water/shower.

P305+P351+P338IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continuerinsing.

P363Wash contaminated clothing before reuse.

Sodium tetrafluoroborate Chemical Properties,Usage,Production

Description

Sodium tetrafluoroborate is an organic compound that has the molecular formula NaBF4. The compound is a salt that forms white or colorless water-soluble rhombic crystals. It is less soluble in organic solvents and readily soluble in water.

Preparation

Sodium tetrafluoroborate can be prepared by reacting tetrafluoroboric with sodium carbonate or hydroxide.
NaOH + HBF4 → NaBF4 + H2O
Na2CO3 + 2 HBF4 → 2 NaBF4 + H2O + CO2

Applications

Sodium tetrafluoroborate can be used as a catalyst for the synthesis of bis(indolyl)methanes via electrophilic substitution reaction of indoles with ketones and aldehydes. In the synthesis of ionic liquids such as trihexyl(tetradecyl)phosphonium tetrafluoroborat and 1-butyl-3-methylimidazolium tetrafluoroborate.
In the laboratory, sodium tetrafluoroborate may be used for the synthesis of boron fluoride. It may also be used in the synthesis of fluoroheterocyclic and fluoro-nucleic acids. The compound is also used in metal finishing, fluxes, and plating circuits.

Chemical Properties

white crystals or powder, crystallizes in the anhydrous form as clear, orthogonal, stubby prisms. Anhydrous NaBF4 does not etch glass. Readily soluble in water. Rhombic crystals, isodimorphous with NaClO4.

Uses

Sodium Tetrafluoroborate is used in various metal finishing and plating circuits.

Uses

Sodium tetrafluoroborate may be used for the laboratory synthesis of boron fluoride. It may be used for the synthesis of fluoro-nucleic acids and fluoroheterocyclic compounds.

Uses

Fluorinating agent, see Lawton, Levy, J. Am. Chem. Soc. 77, 6083 (1955).

General Description

Sodium tetrafluoroborate (NaBF₄) is colorless sodium salt and its crystals belong to the rhombic crystal system. It can be synthesized by reacting tetrafluoroboric acid with sodium carbonate or hydroxide.

Flammability and Explosibility

Not classified

Safety Profile

Moderately toxic by subcutaneous route. When heated to decomposition it emits toxic fumes of Fand Na2O.

Synthesis

Boric acid (6.2 g.) is added, with cooling, to 25 g. of 40% hydrofluoric acid contained in a Pt dish. The mixture is left standing for six hours at room temperature, then cooled with ice, and 5.3 g of dry Na2CO3 is added. The solution is then evaporated until crystallization starts. The salt can be recrystallized from water, whereby large, beautiful single crystals can be obtained. The NaBF4 is finally dried under vacuum.
2 H3BO3 + 8 HF + Na2CO3 = 2 NaBF4 + 7 H2O + CO2

Purification Methods

Crystallise the fluoroborate from hot water (50mL/g) by cooling to 0o. Alternatively, free it from insoluble material by dissolving it in a minimum amount of water; then fluoride ions are removed by adding concentrated lanthanum nitrate in excess. After removing lanthanum fluoride by centrifugation, the supernatant is passed through a cation-exchange column (Dowex 50, Na+-form) to remove any remaining lanthanum [Anbar & Guttman J Phys Chem 64 1896 1960]. It has also been recrystallised from anhydrous MeOH and dried in a vacuum at 70o for 16hours. Keep it dry as it is hygrosopic. [Delville et al. J Am Chem Soc 109 7293 1987.]