20259-33-0Relevant academic research and scientific papers
Infrared spectra of (NO)2+, (NO)2-, and (NO)3- trapped in solid neon
Lugez, Catherine L.,Thompson, Warren E.,Jacox, Marilyn E.,Snis, Anders,Panas, Itai
, p. 10345 - 10358 (1999)
New studies of the infrared spectra of the products which result on codeposition at approximately 5 K of a Ne:NO sample with Ne atoms that have been excited in a microwave discharge have led to new and revised assignments for several ionic species. The appearance of the ν1 absorption of ONNO+ for several new species with asymmetric isotopic substitution, but for no symmetrically substituted species, confirms the trans ground-state configuration for ONNO+. The behavior of a neon-matrix product absorption at 1227.5 cm-1 parallels that of an argon-matrix absorption at 1221.0 cm-1 which has recently been assigned to trans-ONNO-. The identity of the carrier of a product absorption at 1424.1 cm-1, contributed by a vibration of two symmetrically equivalent NO groups, has not been definitively established. This absorption exhibits complex photodestruction behavior. Three absorptions are assigned to cis,cis-(NO)3-, which has C2v symmetry, with the aid of density functional calculations of the isotopic substitution pattern for the vibrational fundamentals of this species. Similar calculations of the isotopic substitution patterns for other structures result in poor agreement with the experiments. Photodestruction of cis,cis-(NO)3- trapped in solid neon yields the N2O...NO2- complex.
Non-Heme Diiron Model Complexes Can Mediate Direct NO Reduction: Mechanistic Insight into Flavodiiron NO Reductases
Dong, Hai T.,White, Corey J.,Zhang, Bo,Krebs, Carsten,Lehnert, Nicolai
supporting information, p. 13429 - 13440 (2018/10/20)
Flavodiiron nitric oxide reductases (FNORs), a common enzyme family found in various types of pathogenic bacteria, are capable of reducing nitric oxide (NO) to nitrous oxide (N2O) as a protective detoxification mechanism. Utilization of FNORs in pathogenic bacteria helps them survive and proliferate in the human body, thus causing chronic infections. In this paper, we present a new diiron model complex, [Fe2((Py2PhO2)MP)(OPr)2](OTf), with bridging propionate ligands (OPr-) that is capable of directly reducing NO to N2O in quantitative yield without the need to (super)reduce the complex. We first prepared the diferric precursor and characterized it by UV-vis, IR, NMR and M?ssbauer spectroscopies, cyclic voltammetry, and mass spectrometry. This complex can then conveniently be reduced to the diferrous complex using CoCp2. Even though this diferrous complex is highly reactive, we have successfully isolated and characterized this species using X-ray crystallography and various spectroscopic techniques. Most importantly, upon reacting this diferrous complex with NO gas, we observe quantitative formation of N2O via IR gas headspace analysis, the first demonstration of direct NO reduction by a non-heme diiron model complex. This finding directly supports recent mechanistic proposals for FNORs.
Over or under: hydride attack at the metal versus the coordinated nitrosyl ligand in ferric nitrosyl porphyrins
Abucayon,Khade,Powell,Shaw,Zhang,Richter-Addo
, p. 18259 - 18266 (2016/11/25)
Hydride attack at a ferric heme-NO to give an Fe-HNO intermediate is a key step in the global N-cycle. We demonstrate differential reactivity when six- and five-coordinate ferric heme-NO models react with hydride. Although Fe-HNO formation is thermodynamically favored from this reaction, Fe-H formation is kinetically favored for the 5C case.
Synchrotron XPS and desorption study of the NO chemistry on a stepped Pt surface
Weststrate,Bakker,Rienks,Vinod,Lizzit,Petaccia,Baraldi,Nieuwenhuys
, p. 1991 - 2001 (2008/10/09)
The interaction of NO with Pt(4 1 0) was studied using high-energy resolution fast XPS and temperature programmed desorption/reaction mass spectroscopy. LEED studies show that the surface in the clean state restructures, which results in the formation of some larger {1 0 0} terraces. STM measurements show, that most terraces are small, ~1 nm. Two different binding energy (BE) components were observed in the N 1s region of the core level spectra, both assigned to molecular forms of NO. NO dissociation starts between 350 and 400 K. This is a significantly higher temperature than previous literature reports suggested. This difference is thought to be caused by the restructuring of the surface used in our experiments. The reaction of NO with H2, NH3 and CO was also studied. The onset of these NO reduction reactions is determined by the NOad dissociation temperature (between 350 and 400 K) and NOad dissociation is the rate limiting step for all the reactions that were studied. Reaction with H2 yields NH3 below 600 K, but the selectivity shifts towards N2 at higher temperatures. We did not find any indication that reaction between NOad and NH3 ad proceeds via a special NO-NH3 intermediate. A new surface species was detected during the reaction between NO and CO, both in the N 1s and the C 1s spectrum. It is tentatively assigned to either CN or CNO. The reactivity of NO on Pt(4 1 0) is compared with the reactivity that was observed for Pt(1 0 0) and other noble metal surfaces, such as Pd and Rh.
