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.
NOBF4 is the nitrosonium salt of fluoroboric acid, and is composed of a nitrosonium cation, +, and a tetrafluoroborate anion, −.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.
Nitrosonium tetrafluoroborate may be used to prepare metal salts of the type 2. The nitrosonium cation acts as the oxidizer, itself being reduced to nitric oxide gas:
With ferrocene the ferrocenium tetrafluoroborate is formed.
