Nitrosonium tetrafluoroborate, also called nitrosyl tetrafluoroborate, is a chemical compound

Chemical compound

A chemical compound is a pure chemical substance consisting of two or more different chemical elements that can be separated into simpler substances by chemical reactions. Chemical compounds have a unique and defined chemical structure; they consist of a fixed ratio of atoms that are held together...

 with the chemical formula

Chemical formula

A chemical formula or molecular formula is a way of expressing information about the atoms that constitute a particular chemical compound....

 NOBF₄. This colourless solid finds use in organic synthesis

Organic synthesis

Organic synthesis is a special branch of chemical synthesis and is concerned with the construction of organic compounds via organic reactions. Organic molecules can often contain a higher level of complexity compared to purely inorganic compounds, so the synthesis of organic compounds has...

 as a nitrosating agent

Nitrosation

Nitrosation is a process of converting organic compounds into nitroso derivatives, i.e. compounds containing the R-NO functionality.-C-Nitroso compounds:C-Nitroso compounds, such as nitrosobenzene, are typically prepared by oxidation of hydroxylamines:...

.

NOBF₄ is the nitrosonium salt of fluoroboric acid

Fluoroboric acid

Fluoroboric acid is the chemical compound with the formula HBF4. It is the conjugate acid of tetrafluoroborate. It is available commercially as a solution in water and other solvents such as diethyl ether...

, and is composed of a nitrosonium

Nitrosonium

The nitrosonium ion is NO+, in which the nitrogen atom is bonded to an oxygen atom with a bond order of 3, and the overall diatomic species bears a positive charge. This ion is usually obtained as the following salts: NOClO4, NOSO4H , and NOBF4. The ClO and BF salts are slightly soluble in CH3CN...

 cation, [NO]⁺, and a tetrafluoroborate

Tetrafluoroborate

Tetrafluoroborate is the anion BF4−. This tetrahedral species is isoelectronic with tetrafluoromethane, CF4 and tetrafluoroammonium NF4+, and is valence isoelectronic with many stable and important species including the closely related anion perchlorate, ClO4−...

 anion, [BF₄]⁻.

Reactions

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: With ferrocene

Ferrocene

Ferrocene is an organometallic compound with the formula Fe2. It is the prototypical metallocene, a type of organometallic chemical compound consisting of two cyclopentadienyl rings bound on opposite sides of a central metal atom. Such organometallic compounds are also known as sandwich compounds...

 the ferrocenium tetrafluoroborate

Ferrocenium tetrafluoroborate

Ferrocenium tetrafluoroborate is an organometallic compound with the formula [Fe2]BF4. This salt is composed of the cation [Fe2]+ and the tetrafluoroborate anion . The related hexafluorophosphate is also a popular reagent with similar properties. The cation is often abbreviated Fc+...

is formed.

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