Nitrogen oxide

Nitrogen oxide may refer to a binary compound of oxygen and nitrogen, or a mixture of such compounds:

Charge-neutral

• Nitric oxide (NO), nitrogen(II) oxide, or nitrogen monoxide
• Nitrogen dioxide (NO₂), nitrogen(IV) oxide
• Nitrogen trioxide (NO₃), or nitrate radical
• Nitrous oxide (N₂O), nitrogen(0,II) oxide
• Dinitrogen dioxide (N₂O₂), nitrogen(II) oxide dimer
• Dinitrogen trioxide (N₂O₃), nitrogen(II,IV) oxide
• Dinitrogen tetroxide (N₂O₄), nitrogen(IV) oxide dimer
• Dinitrogen pentoxide (N₂O₅), nitrogen(V) oxide, or nitronium nitrate [NO₂]⁺[NO₃]⁻
• Nitrosylazide (N₄O), nitrogen(−I,0,I,II) oxide
• Nitryl azide (N₄O₂)
• Oxatetrazole (N₄O)
• Trinitramide (N(NO₂)₃ or N₄O₆), nitrogen(0,IV) oxide

Anions

• Nitroxide (O=N⁻)
• Nitrite (O=N−O⁻ or NO−2)
• Nitrate (NO−3)
• Peroxynitrite (O=N−O−O⁻ or NO−3)
• Peroxynitrate (O₂N−O−O⁻ or NO−4)
• Orthonitrate (NO3−4, analogous to phosphate PO3−4)
• Hyponitrite (⁻O−N=N−O⁻ or N₂O2−2)
• Trioxodinitrate or hyponitrate ([O₂NNO]²⁻ or [N₂O₃]²⁻)
• Nitroxylate ((⁻O−)₂N−N(−O⁻)₂ or N₂O4−4)
• Dinitramide (O₂N−N⁻−NO₂ or N₃O−4)

Cations

• Nitrosonium (N≡O⁺ or [NO]⁺)
• Nitronium (O=N⁺=O or [NO₂]⁺)

Atmospheric sciences

In atmospheric chemistry:

• NO_x (or NOx) refers to the sum of NO and NO₂.
• NO_y (or NOy) refers to the sum of NO_x and all oxidized atmospheric odd-nitrogen species (e.g. the sum of NO_x, HNO₃, HNO₂, etc.)
• NO_z (or NOz) = NO_y − NO_x

• 

  Nitric oxide, NO
• 

  Nitrogen dioxide, NO₂
• 

  Nitrous oxide, N₂O
• 

  Dinitrogen trioxide, N₂O₃
• 

  Dinitrogen tetroxide, N₂O₄
• 

  Dinitrogen pentoxide, N₂O₅
• 

  Trinitramide, N₄O₆

Stability

Due to relatively weak N–O bonding, all nitrogen oxides are unstable with respect to N₂ and O₂, which is the principle behind the catalytic converter and prevents the combustion of the atmosphere.

See also

• Nitrate
• Nitrogen oxide sensor
• Sulfur nitrides, which are valence isoelectronic with nitrogen oxides