Linked Life Data

12032284

Source:http://linkedlifedata.com/resource/pubmed/id/12032284

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
11
pubmed:dateCreated
2002-5-28
pubmed:abstractText
The thermodynamic properties of aqueous nitroxyl (HNO) and its anion (NO(-)) have been revised to show that the ground state of NO(-) is triplet and that HNO in its singlet ground state has much lower acidity, pKa((1)HNO/(3)NO(-)) approximately 11.4, than previously believed. These conclusions are in accord with the observed large differences between (1)HNO and (3)NO(-) in their reactivities toward O(2) and NO. Laser flash photolysis was used to generate (1)HNO and (3)NO(-) by photochemical cleavage of trioxodinitrate (Angeli's anion). The spin-allowed addition of (3)O(2) to (3)NO(-) produced peroxynitrite with nearly diffusion-controlled rate (k = 2.7 x 10(9) M(-1) x s(-1)). In contrast, the spin-forbidden addition of (3)O(2) to (1)HNO was not detected (k << 3 x 10(5) M(-1) x s(-1)). Both (1)HNO and (3)NO(-) reacted sequentially with two NO to generate N(3)O as a long-lived intermediate; the rate laws of N(3)O formation were linear in concentrations of NO and (1)HNO (k = 5.8 x 10(6) M(-1) x s(-1)) or NO and (3)NO(-) (k = 2.3 x 10(9) M(-1) x s(-1)). Catalysis by the hydroxide ion was observed for the reactions of (1)HNO with both O(2) and NO. This effect is explicable by a spin-forbidden deprotonation by OH(-) (k = 4.9 x 10(4) M(-1) x s(-1)) of the relatively unreactive (1)HNO into the extremely reactive (3)NO(-). Dimerization of (1)HNO to produce N(2)O occurred much more slowly (k = 8 x 10(6) M(-1) x s(-1)) than previously suggested. The implications of these results for evaluating the biological roles of nitroxyl are discussed.
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/12032284-10320662, http://linkedlifedata.com/resource/pubmed/commentcorrection/12032284-11042174, http://linkedlifedata.com/resource/pubmed/commentcorrection/12032284-11226215, http://linkedlifedata.com/resource/pubmed/commentcorrection/12032284-11275480, http://linkedlifedata.com/resource/pubmed/commentcorrection/12032284-11461912, http://linkedlifedata.com/resource/pubmed/commentcorrection/12032284-1956043, http://linkedlifedata.com/resource/pubmed/commentcorrection/12032284-1961756, http://linkedlifedata.com/resource/pubmed/commentcorrection/12032284-7526387, http://linkedlifedata.com/resource/pubmed/commentcorrection/12032284-8240347, http://linkedlifedata.com/resource/pubmed/commentcorrection/12032284-8962079, http://linkedlifedata.com/resource/pubmed/commentcorrection/12032284-9576846
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0027-8424
pubmed:author
pubmed:issnType
Print
pubmed:day
28
pubmed:volume
99
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
7340-5
pubmed:dateRevised
2009-11-18
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Nitroxyl and its anion in aqueous solutions: spin states, protic equilibria, and reactivities toward oxygen and nitric oxide.
pubmed:affiliation
Chemistry Department and Radiation and Solid-State Laboratory, New York University, New York 10003, USA. vs5@nyu.edu
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't