Nitrosonium tetrafluoroborate
| Names | |
|---|---|
| IUPAC name
Nitrosonium tetrafluoroborate
| |
| Other names
Azanylidyneoxidanium tetrafluoroborate
Nitrosium tetrafluoroborate Nitrosyl tetrafluoroborate | |
| Properties | |
| NOBF4 | |
| Molar mass | 116.81 g/mol |
| Appearance | Colorless crystalline solid |
| Odor | Odorless (dry air) Acidic (moisture) |
| Density | 2.185 g/cm3[1] |
| Melting point | 250 (decomposes) |
| Boiling point | Decomposes |
| Reacts | |
| Solubility | Reacts with alcohols Soluble in acetonitrile, conc. sulfuric acid Sparingly soluble in benzonitrile, liq. nitrosyl chloride[2] Insoluble in CCl4, dichloromethane, nitromethane |
| Vapor pressure | ~0 mmHg |
| Thermochemistry | |
| Hazards | |
| Safety data sheet | Sigma-Aldrich |
| Flash point | Non-flammable |
| Related compounds | |
| Related compounds
|
Nitronium tetrafluoroborate |
| Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
| Infobox references | |
Nitrosonium tetrafluoroborate, also called nitrosyl tetrafluoroborate, is a chemical compound with the chemical formula NOBF4, the nitrosonium salt of fluoroboric acid. This colourless solid is used in organic synthesis as a nitrosating agent.
Contents
Properties
Chemical
The dominant property of NOBF4 is the oxidizing power and electrophilic character of the nitrosonium cation. It forms colored charge transfer complexes with hexamethylbenzene and with 18-crown-6. The latter, a deep yellow species, provides a means to dissolve NOBF4 in dichloromethane.
Nitrosonium tetrafluoroborate reacts with aliphatic azides to yield the corresponding alkyl fluorides.
With ferrocene the ferrocenium tetrafluoroborate is formed.
Physical
Nitrosonium tetrafluoroborate is a colorless crystalline solid, that react with water.
Availability
Nitrosonium tetrafluoroborate is sold by chemical suppliers.
Preparation
Nitrosonium tetrafluoroborate can be prepared by adding perfectly dry hydrogen fluoride and nitrogen dioxide to boron trifluoride. Given the highly corrosive nature of the reagents used, this reaction is done in a chemical resistant polyethylene reactor. The reaction takes place is dry nitromethane, in a nitrogen atmosphere, at -20°C under continuous stirring. The yield of this reaction can reach 97%.[4] Dinitrogen pentoxide can be used instead, though the resulting yield is lower, at 89%.[5]
Another route involves reacting boron trifluoride with dry hydrogen fluoride and nitrosyl chloride, in liq. SO2, at -10°C, while stirring for 15-30 min. The final product is washed with dichloromethane. Yield is 96%.[6] One source indicates that hydrogen fluoride can be replaced with boron trioxide, and the yield will be the same.[7]
Injecting dry nitrogen dioxide in a solution of tetrafluoroboric acid will yield nitrosyl tetrafluoroborate, with nitric acid being produced as side product.[8]
Addition of dinitrogen trioxide to boron trifluoride, in nitrobenzene or liq. SO2 at 0 °C will also yield NOBF4.[9]
Projects
- Nitrosating agent
- Preparation of tetrafluoroborate compounds
- Synthesis of HNIW
Handling
Safety
Nitrosonium tetrafluoroborate reacts with water, it's corrosive and toxic.
Storage
In closed airtight bottles, at low temperature, in a dry medium. Schlenks flask may also be used if available.
Disposal
Should be added slowly to water to safely hydrolyze it, then neutralized with a base.
References
- ↑ Balz, G.; Mailaender, E.; Z. Anorg. Chem.; vol. 217; (1934); p. 161 - 169
- ↑ Yau, John; Mingos, D. Michael P.; Journal of the Chemical Society, Dalton Transactions: Inorganic Chemistry (1972-1999); (1997); p. 1103 - 1112
- ↑ Callanan, J.E.; Granville, N.W.; Green, N.H.; Staveley, L.A.K.; Weir, R.D.; White, M.A.; Journal of Chemical Physics; vol. 74; nb. 3; (1981); p. 1911 - 1915
- ↑ https://www.thieme-connect.de/products/ebooks/lookinside/10.1055/b-0035-111179
- ↑ Schmeiser, M.; Elischer, S.; Zeitschrift fuer Naturforschung; vol. 7b; (1952); p. 583
- ↑ Kuhn, S. J.; Canadian Journal of Chemistry; vol. 45; (1967); p. 3207 - 3209
- ↑ Woolf, A. A.; Journal of the Chemical Society; (1950); p. 1053 - 1056
- ↑ Voznesenskij, S. A.; Kurskij, P. P.; Zhurnal Obshchei Khimii; vol. 8; (1938); p. 524 - 528 ;
- ↑ Evans, J. C.; Rinn, H. W.; Kuhn, S. J.; Olah, G. A.; Inorganic Chemistry; vol. 3; (1964); p. 857 - 861
