title: Mechanism of pH-dependent decomposition of monoalkylamine diazeniumdiolates to form HNO and NO, deduced from the model compound methylamine diazeniumdiolate, density functional theory, and CBS-QB3 calculations.
abstract: Isopropylamine diazeniumdiolate, IPA/NO, the product of the reaction of isopropylamine and nitric oxide, NO, decomposes in a pH-dependent manner to afford nitroxyl, HNO, in the pH range of 13 to above 5, and NO below pH 7. Theoretical studies using B3LYP/6-311+G(d) density functional theory, the polarizable continuum and conductor-like polarizable continuum solvation models, and the high-accuracy CBS-QB3 method on the simplified model compound methylamine diazeniumdiolate predict a mechanism involving HNO production via decomposition of the unstable tautomer MeNN+(O-)NHO-. The production of NO at lower pH is predicted to result from fragmentation of the amide/NO adduct upon protonation of the amine nitrogen.
authors.affiliation: Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, USA.
authors.forename: Andrew S
authors.initials: AS
authors.lastname: Dutton
authors.forename: Christopher P
authors.initials: CP
authors.lastname: Suhrada
authors.forename: Katrina M
authors.initials: KM
authors.lastname: Miranda
authors.forename: David A
authors.initials: DA
authors.lastname: Wink
authors.forename: Jon M
authors.initials: JM
authors.lastname: Fukuto
authors.forename: K N
authors.initials: KN
authors.lastname: Houk
mesh_terms: D001372:Aza Compounds / Q000737:chemistry*; D001391:Azo Compounds / Q000737:chemistry*; D004563:Electrochemistry; D006863:Hydrogen-Ion Concentration; D008744:Methylamines / Q000737:chemistry*; D008956:Models, Chemical; D015394:Molecular Structure; D009569:Nitric Oxide / Q000737:chemistry*; D009589:Nitrogen Oxides / Q000737:chemistry*; D013816:Thermodynamics
chemical_list: D001372:Aza Compounds; D001391:Azo Compounds; D008744:Methylamines; D009589:Nitrogen Oxides; C452539:diazeniumdiolate; C518951:methylamine diazeniumdiolate; D009569:Nitric Oxide; C039900:nitroxyl