On the acidity and reactivity of HNO in aqueous solution and biological systems.
The gas phase and aqueous thermochemistry and reactivity of nitroxyl (nitrosyl hydride, HNO) were elucidated with multiconfigurational self-consistent field and hybrid density functional theory calculations and continuum solvation methods. The pK(a) of HNO is predicted to be 7.2 +/- 1.0, considerably different from the value of 4.7 reported from pulse radiolysis experiments. The ground-state triplet nature of NO(-) affects the rates of acid-base chemistry of the HNO/NO(-) couple. HNO is highly reactive toward dimerization and addition of soft nucleophiles but is predicted to undergo negligible hydration (K(eq) = 6.9 x 10(-5)). HNO is predicted to exist as a discrete species in solution and is a viable participant in the chemical biology of nitric oxide and derivatives.
Bartberger
M D
MD
Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90995-1569, USA.
Fukuto
J M
JM
Houk
K N
KN
D019281:Dimerization; D006863:Hydrogen-Ion Concentration; D009589:Nitrogen Oxides / Q000737:chemistry*; D012996:Solutions; D014867:Water
D009589:Nitrogen Oxides; D012996:Solutions; D014867:Water; C039900:nitroxyl