Nitrosonium tetrafluoroborate

Nitrosonium tetrafluoroborate, also called nitrosyl tetrafluoroborate, is a chemical compound with the chemical formula NOBF₄. This colourless solid is used in organic synthesis as a nitrosating agent.^[1]

Nitrosonium tetrafluoroborate

Names
IUPAC name nitrosonium tetrafluoroborate
Other names nitrosyl tetrafluoroborate
Identifiers
CAS Number	14635-75-7 Y
3D model (JSmol)	Interactive image
ChemSpider	9312255 N
ECHA InfoCard	100.035.148
PubChem CID	151929
UNII	B99S282SUJ Y
CompTox Dashboard (EPA)	DTXSID101015532
InChI InChI=1S/BF4.NO/c2-1(3,4)5;1-2/q-1;+1 N Key: KGCNVGDHOSFKFT-UHFFFAOYSA-N N
SMILES [B-](F)(F)(F)F.N#[O+]
Properties
Chemical formula	BF4NO
Molar mass	116.81 g·mol−1
Appearance	colourless crystalline solid
Density	2.185 g cm−3
Melting point	250 °C (482 °F; 523 K) (sublimes)
Solubility in water	decomposes
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references

NOBF₄ is the nitrosonium salt of fluoroboric acid, and is composed of a nitrosonium cation, [NO]⁺, and a tetrafluoroborate anion, [BF₄]⁻.

Reactions

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.^[2]

Nitrosonium tetrafluoroborate may be used to prepare metal salts of the type [M^II(CH₃CN)_x][BF₄]₂ (M = Cr, Mn, Fe, Co, Ni, Cu). The nitrosonium cation acts as the oxidizer, itself being reduced to nitric oxide gas:^[3]

M + 2NOBF₄ + xCH₃CN → [M(CH₃CN)_x](BF₄)₂ + 2NO

With ferrocene the ferrocenium tetrafluoroborate is formed.^[4]

In its infrared spectrum of this salt, ν_NO is a strong peak at 2387 cm⁻¹.^[5]

References

1. "A15806 Nitrosonium tetrafluoroborate, 98%". Alfa Aesar website. Retrieved 2010-09-04.
2. Lee, K. Y.; Kuchynka, D. J.; Kochi, Jay K. (1990). "Redox equilibria of the nitrosonium cation and of its nonbonded complexes". Inorganic Chemistry. 29 (21): 4196–4204. doi:10.1021/ic00346a008.
3. Heintz, Robert A.; Smith, Jennifer A.; Szalay, Paul S.; Weisgerber, Amy; Dunbar, Kim R. (August 2004). "11. Homoleptic Transition Metal Acetonitrile Cations with Tetrafluoroborate or Trifluoromethanesulfonate Anions". Inorg. Synth. 33: 75–83. doi:10.1002/0471224502.ch2. ISBN 978-0-471-46075-6.
4. Roger M. Nielson; George E. McManis; Lance K. Safford; Michael J. Weaver (1989). "Solvent and electrolyte effects on the kinetics of ferrocenium-ferrocene self-exchange. A reevaluation". J. Phys. Chem. 93 (5): 2152. doi:10.1021/j100342a086.
5. Sharp, D. W. A.; Thorley, J. (1963). "670. The Infrared Spectrum of the Nitrosonium Ion". Journal of the Chemical Society (Resumed): 3557. doi:10.1039/JR9630003557.