7803-49-8Relevant articles and documents
An experimental and theoretical study of the vibrationally mediated photodissociation of hydroxylamine
Luckhaus, David,Scott, Jacqueline L.,Crim, F. Fleming
, p. 1533 - 1541 (1999)
We present a detailed investigation of the photodissociation of hydroxylamine following direct single-photon and vibrationally mediated two-photon excitation below 42 000 cm-1. In all cases the lowest dissociation channel [NH2(X 2B1)+OH(X 2Π)] dominates. Single-photon dissociation at 240 nm releases most of the excess energy (20 550 cm-1) into relative translation (53%) and NH2 internal energy (40%, mostly vibrational). OH carries little internal energy (7%), most of it in the form of rotational excitation. Torsional excitation during the dissociation step leads to rotational alignment of the OH fragments and a preferential population of the Π(A′) component of the lambda doublet. Both are lost after isoenergetic two-photon excitation via O-H stretching overtones of NH2OH, also leading to higher internal excitation of the NH2 fragments (～50%) at the expense of relative translation. At lower total excitation energies the relative translation takes up an increasing fraction of the total excess energy (≥80% at 5820 cm-1 of excess energy). The results are discussed in terms of ab initio calculations using complete active space second-order perturbation theory with augmented triple-ζ basis sets for the lowest excited singlet states. One- and two-dimensional potential functions explain the OH product state distributions observed in different experiments in terms of the geometry relaxation of NH2OH upon electronic excitation. Crossing between the lowest excitated A′ and A′ singlet states in the Franck-Condon region leads to a barrier of ～0.5 eV to dissociation in S1, which dominates the photodissociation dynamics.
Kinetic and mechanistic studies on the reactions of the reduced vitamin B12 complex cob(I)alamin with nitrite and nitrate
Plymale, Noah T.,Dassanayake, Rohan S.,Hassanin, Hanaa A.,Brasch, Nicola E.
, p. 913 - 921 (2012)
The kinetics of the reactions between cob(I)alamin [Cbl(I)] and nitrite and nitrate have been studied by UV/Vis and stopped-flow spectroscopy. Enzyme-bound Cbl(I) is an important transient species in several B12-catalyzed enzyme reactions. Levels of nitrite and nitrate are elevated during oxidative stress, as a consequence of elevated nitric oxide levels. Although nitrite and nitrate are generally considered to be benign species, our studies show that nitrate and especially nitrite react rapidly with Cbl(I) at neutral pH conditions (kapp = 6.5×10-3 and 1.7×10 3 M-1 s-1, respectively, at pH 7, 25.0 °C). A reaction pathway is postulated for the reaction between Cbl(I) and (H)NO 2 involving a 2e- rate-determining step to form Cbl(III) and HNO. The latter species reacts further with Cbl(I), ultimately resulting in the oxidation of 4Cbl(I) by HNO2 to yield 4Cbl(II) and NH 2OH. The reaction between Cbl(I) and (H)NO3 results in the oxidation of 8Cbl(I) by (H)NO3 to give 8Cbl(II) and NH 4+ (pH 5-7). Kinetic studies show that nitrate and especially nitrite react rapidly with cob(I)alamin under biological pH conditions. Copyright
Electrocatalytic Multielectron Nitrite Reduction in Water by an Iron Complex
Stroka, Jesse R.,Kandemir, Banu,Matson, Ellen M.,Bren, Kara L.
, p. 13968 - 13972 (2020)
Catalytic reduction of nitrite by an iron complex in water near neutral pH to form hydroxylamine and ammonium is reported. The catalyst is an iron center coordinated by the pentadentate macrocycle 2,13-dimethyl-3,6,9,12,18-pentaazabicyclo[12.3.1]octadeca-1(18),2,12,14,16-pentaene (FeN5H2). Catalysis is observed by cyclic voltammetry at a half-wave potential of Ep/2 = -0.98 V vs Ag/AgCl (1 M KCl) when FeN5H2, nitrite, and a buffer (pH 7.2) are present. Controlled potential electrolysis of FeN5H2 and nitrite in pH 7.2 buffer at -0.98 V produces hydroxylamine (faradaic efficiency > 90%). FeN5H2 catalyzes ammonium production by disproportionation of hydroxylamine with concomitant formation of nitrous oxide and dinitrogen. These results are a rare example of multielectron electrocatalytic nitrite reduction by an iron complex near neutral pH.
THE FORMATION OF HYDROXYLAMINE BY INSERTION OF THE NH(1Δ) RADICAL INTO THE O-H BOND OF WATER
Kawai, Jun,Tsunashima, Shigeru,Sato, Shin
, p. 823 - 826 (1983)
The photolysis of hydrogen azide was examined in water.The main products were nitrogen and hydroxylamine.Hydroxylamine formed was converted into acetoxime by the reaction with acetone which was added after irradiation.The amount of acetoxime was analyzed
A feature of reaction of 1,1′-diacetylferrocene with dimethylformamide dimethyl acetal leading to a new strategy of the synthesis of asymmetrical 1,1′-disubstituted ferrocene
Moskalenko,Boeva,Boev
, p. 529 - 534 (2011)
The reaction of 1,1′-diacetylferrocene with the dimethylformamide dimethyl acetal proceeds regioselectively to afford [1-acetyl-1′-(1- dimethylamino-3-oxoprop-1-en-3-yl)]ferrocene, based on which new approaches to the synthesis of 1,1′-disubstituted unsymmetrical ferrocene derivatives via the reaction with nucleophilic reagents hydrazine hydrate, hydroxylamine, and amidines were developed.
Versatility and trends in the interaction between Pd(ii) and peptide hydroxamic acids
Ozsváth, András,Farkas, Etelka,Diószegi, Róbert,Buglyó, Péter
, p. 8239 - 8249 (2019)
Primary and secondary di- and tripeptide hydroxamic acids, Ala-Ala-NHOH, Ala-Ala-N(Me)OH, Ala-Gly-Gly-NHOH and Ala-Gly-Gly-N(Me)OH were synthesized and their interaction with Pd(ii) (as a Pt(ii) model but with faster ligand exchange reactions) was studied in aqueous solution in the presence of the Cl- competitor ion by pH-potentiometric and 1H NMR methods. To the best of our knowledge, this is the first detailed solution study on Pd(ii)-peptide hydroxamate systems revealing that, except for Ala-Gly-Gly-NHOH, the other three ligands act not only as coordination compounds, but also the hydrolysis of the coordinated ligands and formation of the protonated hydroxylamine and Pd(ii) complexes of the corresponding peptides under acidic conditions occurred. The hydrolysis was rather slow with Ala-Gly-Gly-N(Me)OH (more than one week), and just a bit faster with Ala-Ala-NHOH, so speciation studies could also be performed successfully on the systems containing one of the latter two ligands. This was, however, hindered for the Pd(ii)-Ala-Ala-N(Me)OH system, where, in addition to the quite fast hydrolysis of the ligand, the reduction of Pd(ii) to elementary metal by the N(Me)-hydroxylamine formed was also observed. Speciation studies with Ala-Gly-Gly-NHOH revealed the predominance of a very stable 4N-donor complex, (NH2, 2Namide, Nhydr.) over a wide pH range. This ligand is also capable of binding the metal ion excess with the hydroxymate (O,O) set in dinuclear species. The formation of this latter type of complex is hindered with the secondary analogue, Ala-Gly-Gly-N(Me)OH, where, in addition to the 3N donor atoms, the hydroxamate-O is also involved in the coordination of the most stable complex. However, the formation of mixed hydroxo species at high pH and a bis-complex in a rather slow process with (NH2, Namide)2 bonding mode in the presence of ligand excess was proven. Although the 3N coordination (NH2, Namide, Nhydx) results in a highly stable complex with the dipeptide derivative, Ala-Ala-NHOH, the fourth coordination site remains free for accepting an NH2 moiety from the excess ligand, or a hydroxide ion at high pH. Likewise, the hydroxymate (O,O) set remains free to bind the metal ion excess in a trinuclear species. The results of this study may also contribute to the design and synthesis of novel Pt(ii) complexes with anticancer potential.
Reaction of acetylferrocene with dimethylformamide dimethyl acetal and some transformations of the reaction product
Moskalenko,Boeva,Boev
, p. 521 - 528 (2011)
1-Dimethylamino-3-ferrocenyl-3-oxoprop-1-ene was synthesized by the reaction of acetylferrocene with dimethylformamide dimethyl acetal. Its reactivity in the reactions with mononucleophilic (sodium salts of phenol, thiophenol, benzenesulfinate, diethylphosphorous acid) and binucleophilic reagents (hydrazine hydrate, hydroxylamine, amidines, 1,2-diaminobenzene, 2-aminophenol, 2-aminothiophenol) and methyl iodide was studied. As a result, we obtained new ferrocene-containing α-keto-unsaturated compounds and heterocycles of pyrazole, isoxazole, pyrimidine, and benzazepine series. In the reaction with CH3I formed ferrocenoylacetylene which in the presence of dicarbonyl-bis(triphenylphosphine)nickel catalyst easily trimerized to give a mixture of 1,2,4- and 1,3,5-triferrocenoylbenzene.
Thermodynamic and kinetic analysis of isothermal microcalorimetric data: Applications to consecutive reaction schemes
Gaisford, Simon,Hills, Andrew K.,Beezer, Anthony E.,Mitchell, John C.
, p. 39 - 45 (1999)
Recent developments have led to a general procedure that allows the analysis of isothermal microcalorimetric data to determine both kinetic and thermodynamic information. Such an analysis means that isothermal microcalorimetry is a powerful technique with which to gain information on a wide range of reactions. Previously, the method of analysis has, principally, been applied to simple, two-state, solution phase reactions. It is the purpose of the data presented here to show how such an analysis may be applied to solution phase reactions that follow more complex, consecutive reaction pathways using, as a model and example, the acid catalyzed hydrolysis of potassium hydroxylamine trisulfonate.
Application of an immobilized ionic liquid for the preparation of hydroxylamine via hydrolysis of cyclohexanone oxime
Wang, Shuangyu,Liu, Jiaqi,Cheng, Peng,Li, Zhihui,Zhang, Dongsheng,Yang, Qiusheng,Zhao, Xinqiang,Wang, Yanji
, p. 742 - 750 (2021/02/05)
Preparation of hydroxylamine via hydrolysis of cyclohexanone oxime was studied over porous SiO2 supported acid ionic liquid catalyst. The catalyst [SPIPTES]CF3SO3@SiO2 was prepared through sol-gel method and characterized by elemental analysis, IR and TG, etc. Various parameters such as reaction temperature and time, catalyst amount were investigated systematically. The optimized reaction conditions investigated were catalyst:cyclohexanone oxime (mass ratio) 4 : 1, conducted at 60 °C for 1 h. Since the present hydrolysis reaction is controlled by thermodynamics, the conversion of cyclohexanone oxime could not be very high. However, reasonable result was achieved under the optimized reaction conditions. Cyclohexanone oxime conversion was 38.41 % and NH2OH yield was 37.65 %. Additionally, combining experiments with density functional theory calculations, a possible catalyst structure and reaction pathway involved protonated cyclohexanone oxime mechanism was proposed for the present hydrolysis in this study.
Electrochemical Nitric Oxide Reduction on Metal Surfaces
Bagger, Alexander,Rossmeisl, Jan,Wan, Hao
supporting information, p. 21966 - 21972 (2021/09/02)
Electrocatalytic denitrification is a promising technology for removing NOx species (NO3?, NO2? and NO). For NOx electroreduction (NOxRR), there is a desire for understanding the catalytic parameters that control the product distribution. Here, we elucidate selectivity and activity of catalyst for NOxRR. At low potential we classify metals by the binding of *NO versus *H. Analogous to classifying CO2 reduction by *CO vs. *H, Cu is able to bind *NO while not binding *H giving rise to a selective NH3 formation. Besides being selective, Cu is active for the reaction found by an activity-volcano. For metals that does not bind NO the reaction stops at NO, similar to CO2-to-CO. At potential above 0.3 V vs. RHE, we speculate a low barrier for N coupling with NO causing N2O formation. The work provides a clear strategy for selectivity and aims to inspire future research on NOxRR.
