20509-24-4Relevant articles and documents
Nickel-mediated N-N bond formation and N2O liberationvianitrogen oxyanion reduction
Beagan, Daniel M.,Cabelof, Alyssa C.,Carta, Veronica,Caulton, Kenneth G.,Gao, Xinfeng,Pink, Maren
, p. 10664 - 10672 (2021/08/20)
The syntheses of (DIM)Ni(NO3)2and (DIM)Ni(NO2)2, where DIM is a 1,4-diazadiene bidentate donor, are reported to enable testing of bis boryl reduced N-heterocycles for their ability to carry out stepwise deoxygenation of coordinated nitrate and nitrite, forming O(Bpin)2. Single deoxygenation of (DIM)Ni(NO2)2yields the tetrahedral complex (DIM)Ni(NO)(ONO), with a linear nitrosyl and κ1-ONO. Further deoxygenation of (DIM)Ni(NO)(ONO) results in the formation of dimeric [(DIM)Ni(NO)]2, where the dimer is linked through a Ni-Ni bond. The lost reduced nitrogen byproduct is shown to be N2O, indicating N-N bond formation in the course of the reaction. Isotopic labelling studies establish that the N-N bond of N2O is formed in a bimetallic Ni2intermediate and that the two nitrogen atoms of (DIM)Ni(NO)(ONO) become symmetry equivalent prior to N-N bond formation. The [(DIM)Ni(NO)]2dimer is susceptible to oxidation by AgX (X = NO3?, NO2?, and OTf?) as well as nitric oxide, the latter of which undergoes nitric oxide disproportionation to yield N2O and (DIM)Ni(NO)(ONO). We show that the first step in the deoxygenation of (DIM)Ni(NO)(ONO) to liberate N2O is outer sphere electron transfer, providing insight into the organic reductants employed for deoxygenation. Lastly, we show that at elevated temperatures, deoxygenation is accompanied by loss of DIM to form either pyrazine or bipyridine bridged polymers, with retention of a BpinO?bridging ligand.
Lewis Acid Activation of the Ferrous Heme-NO Fragment toward the N-N Coupling Reaction with NO to Generate N2O
Abucayon, Erwin G.,Khade, Rahul L.,Powell, Douglas R.,Zhang, Yong,Richter-Addo, George B.
supporting information, p. 4204 - 4207 (2018/04/05)
Bacterial NO reductase (bacNOR) enzymes utilize a heme/non-heme active site to couple two NO molecules to N2O. We show that BF3 coordination to the nitrosyl O-atom in (OEP)Fe(NO) activates it toward N-N bond formation with NO to generate N2O. 15N-isotopic labeling reveals a reversible nitrosyl exchange reaction and follow-up N-O bond cleavage in the N2O formation step. Other Lewis acids (B(C6F5)3 and K+) also promote the NO coupling reaction with (OEP)Fe(NO). These results, complemented by DFT calculations, provide experimental support for the cis:b3 pathway in bacNOR.
Isotopic Evidence for Direct Conversion of NO to NH3 in the Absence of O2 over V2O5/TiO2 and α-Cr2O3 Selective Catalytic Reduction Catalysts
Duffy, Bronwyn L.,Curry-Hyde, H. Edward,Cant, Noel W.,Nelson, Peter F.
, p. 1729 - 1732 (2007/10/02)
The products of the reaction between (15)NO and (14)NH3 over V2O5/TiO2 and α-Cr2O3 catalysts in the absence of oxygen have been determined by mass spectrometry and Fourier transform infrared spectroscopy.With both catalysts (14)N(15)N comprises approximat
Kinetic, isotopic, and 15N NMR study of N-hydroxybenzenesulfonamide decomposition: An HNO source reaction
Bonner, Francis T.,Ko, Younghee
, p. 2514 - 2519 (2008/10/08)
Decomposition of N-hydroxybenzenesulfonamide (C6H5SO2NHOH) in alkaline solution to yield N2O and sulfinate (C6H5SO2-) is first order in C6H5SO2NHO-, with rate constant = 2.44 (±0.23) × 10-4 s-1 at 25°C, ΔH? = 94.1 kJ mol-1, and ΔS? = 6.64 J K-1 mol-1. The reaction occurs via reversible release of HNO (and/or its conjugate NO-), followed by rapid dimerization of the intermediate to form N2O. It is shown by 15N tracer methods that this species and the NO- intermediate formed in trioxodinitrate decomposition are capable of codimerization, showing them to be in the same (singlet) electronic state. Protonation of C6H5SO2NHO- brings about a 15N NMR shift of -28.6 ppm. The free acid and its basic anion exhibit identical, large NOEF values (-4.16), showing that the dissociable hydrogen in C6H5SO2NHOH is bound to oxygen rather than to nitrogen, despite contrary literature reports.
Mechanism of the Catalytic Reduction of Nitric Oxide by Ammonia over Cobalt-Amine Complexes in Na-Y Zeolite
Naito, Shuichi,Tamaru, Kenzi
, p. 315 - 319 (2007/10/02)
The mechanism of the NO-NH3 reaction over Co(en)2(NO2)3 complex (en=ethylenediamine), ion exchanged into Na-Y zeolite, was studied extensively and compared with that by the same complex in an aqueous solution, which has been reported previously.At room temperature, the catalytically active species are similar in both media, exhibiting similar reaction mechanisms.Ammonia treatment of the catalyst at 363 K caused the reduction of cobalt cation to CoII with the removal of NO2 groups.The catalytic behavior of this CoII(en)-Y zeolite was compared to that of CoII(NH3)-Y zeolite, prepared by a conventional cation-exchange method.During the No-NH3 reaction, mononitrosyl and dinitrosyl intermediate species were much more stable in Co(NH3) zeolite than Co(en)-Y zeolite, resulting in different reaction orders and kinetic isotope effects.It is demonstrated that a zeolite cavity can be a microreactor, where residual water acts as a solvent to assist the stabilization of the catalytically active species.
