Peroxynitrous acid (HNO3) is a reactive nitrogen species (RNS). It is the conjugate acid of peroxynitrite (ONOO−). It has a pKa of approximately 6.8. It is formed in vivo from the diffusion-controlled reaction of nitrogen monoxide (ON•) and superoxide (O•−
2). It is an isomer of nitric acid and isomerises with a rate constant of k = 1.2 s−1, a process whereby up to 5% of hydroxyl and nitrogen dioxide radicals may be formed. It oxidises and nitrates aromatic compounds in low yield. The mechanism may involve a complex between the aromatic compound and ONOOH, and a transition from the cis- to the trans-configuration of ONOOH.[3] Peroxynitrous acid is also important in atmospheric chemistry.

References

  1. ^ N.Connelly and T. Damhus, IUPAC. Nomenclature of Inorganic Chemistry, RSC Publishing, Cambridge, 2005
  2. ^ "Peroxynitrous Acid - Compound Summary". PubChem Compound. USA: National Center for Biotechnology Information. 16 September 2004. Identification and Related Records. Retrieved 11 April 2012.
  3. ^ Koppenol, W. H.; Bounds, P. L.; Nauser, T.; Kissner, R.; Rüegger, H. (2012). "Peroxynitrous acid: controversy and consensus surrounding an enigmatic oxidant". Dalton Transactions. 41: 13779–13787.