7782-77-6Relevant articles and documents
The importance of NO+(H2O)4 in the conversion of NO+(H2O)n to H3O +(H2O)n: I. Kinetics measurements and statistical rate modeling
Eyet, Nicole,Shuman, Nicholas S.,Viggiano, Albert A.,Troe, Juergen,Relph, Rachael A.,Steele, Ryan P.,Johnson, Mark A.
, p. 7582 - 7590 (2011)
The kinetics for conversion of NO+(H2O)n to H3O+(H2O)n has been investigated as a function of temperature from 150 to 400 K. In contrast to previous studies, which show that the conversion goes completely through a reaction of NO +(H2O)3, the present results show that NO +(H2O)4 plays an increasing role in the conversion as the temperature is lowered. Rate constants are derived for the clustering of H2O to NO+(H2O)1-3 and the reactions of NO+(H2O)3,4 with H 2O to form H3O+(H2O)2,3, respectively. In addition, thermal dissociation of NO+(H 2O)4 to lose HNO2 was also found to be important. The rate constants for the clustering increase substantially with the lowering of the temperature. Flux calculations show that NO+(H 2O)4 accounts for over 99% of the conversion at 150 K and even 20% at 300 K, although it is too small to be detectable. The experimental data are complimented by modeling of the falloff curves for the clustering reactions. The modeling shows that, for many of the conditions, the data correspond to the falloff regime of third body association.
A convenient preparation of pentaaquanitrosylchromium(2+) sulfate: The crystal structure revisited
D?ssing, Anders,Frey, Anne Mette
, p. 1681 - 1684 (2006)
The complex pentaaquanitrolsylchromium(2+) sulfate, [Cr(OH 2)5(NO)]SO4 has been prepared in a high yield by the hydrolysis of [Cr(NCCH3)5(NO)](BF4) 2 in dilute sulfuric acid. Crystals of [Cr(OH2) 5(NO)]SO4·H2O have been grown and characterized by X-ray crystallography. Continuous photolysis of [Cr(NCCH 3)5(NO)]2+ in acetonitrile solution with 404 nm light results in a release of NO with the quantum yield Φ = 0.55 mol einstein-1 at 298 K with the resulting solvated Cr2+ ion being trapped by molecular dioxygen present in the solution.
Production processes of H(D) atoms in the reactions of NO(A2Σ+) with C2H2, C2H4, H2O, and their isotopic variants
Umemoto, Hironobu,Terada, Naoki,Tanaka, Kunikazu,Takayanagi, Toshiyuki,Kurosaki, Yuzuru,Yokoyama, Keiichi
, p. 39 - 47 (2000)
The production of H(D) atoms was identified in the reactions of NO(A2Σ+) with C2H2, C2H4, H2O, and their isotopic variants. By measuring the Doppler profiles, the translational energies of H(D) atoms were determined. As for C2H2 and H2O, around 1/4 of the NO(A2Σ+) energy is partitioned into the translational mode, while the ratio is around 1/7 for C2H4. Such a large partitioning of the available energy into the translational mode cannot be explained by a C-H(O-H) bond rupture after an energy transfer. Nitrogen compounds, such as ONC2H and HONO, must be produced as pair products. The measured translational energies are much larger than those statistically expected, suggesting that the intermediate species are short-lived. No large isotope effect was observed in the average translational energies or in the relative yields. Quantum effects, such as tunneling, do not play important roles. Ab initio molecular orbital calculations were carried out to characterize these reactive processes. (C) 2000 Elsevier Science B.V.
OH overtone spectra and intensities of pernitric acid
Fono, Lorien,Donaldson,Proos, Robert J.,Henry, Bryan R.
, p. 131 - 138 (1999)
The integrated absorption intensities of the 3νOH overtone transitions of the OH stretch of pernitric acid (HO2NO2) and nitric acid (HONO2) were measured in concentrated sulfuric acid (H2SO4) solution. As well, oscillator strengths for the OH overtones of isolated HO2NO2 were calculated ab initio. Both results indicate that the OH overtones of HO2NO2 have larger oscillator strengths than the corresponding transitions in HONO2 (1.3±0.5 times greater in H2SO4 solution; about 2 times greater according to the ab initio calculations). Overtone-induced photodissociation of HO2NO2 could play a role in HOx production at high solar zenith angles.
Fine tuning the reactivity of corrole-based catalytic antioxidants
Okun, Zoya,Gross, Zeev
, p. 8083 - 8090 (2012)
In order to determine the electronic factors that may affect the catalytic antioxidant activity of water-soluble metallocorroles a series of 10-aryl-5,15-pyridinium manganese(III) corroles was prepared. These complexes were examined regarding the effect of the C10 substituent on the MnIV/MnIII redox potentials, catalytic rate constants for decomposition of HOONO, prevention of tyrosine nitration, and superoxide dismutase activity. This structure-activity relationship investigation provides new insight regarding the mechanism by which manganese(III) corroles act as catalytic antioxidants. It also discloses the superiority of the C 10-anysil-substituted complex in all examined aspects.
Potential role of the nitroacidium ion on HONO emissions from the snowpack
Hellebust, Stig,Roddis, Tristan,Sodeau, John R.
, p. 1167 - 1171 (2007)
The effects of photolysis on frozen, thin films of water-ice containing nitrogen dioxide (as its dimer dinitrogen tetroxide) have been investigated using a combination of Fourier transform reflection - absorption infrared (FT-RAIR) spectroscopy and mass spectrometry. The release of HONO is ascribed to a mechanism in which nitrosonium nitrate (NO+NO3 -) is formed. Subsequent solvation of the cation leads to the nitroacidium ion, H2ONO+, i.e., protonated nitrous acid. The pathway proposed explains why the field measurement of HONO at different polar sites is often contradictory.
Crystal structure, optical, magnetic, and photochemical properties of the complex pentakis(dimethyl sulfoxide)nitrosylchromium(2+) hexafluorophosphate
Dethlefsen, Johannes W.,D?ssing, Anders,Kadziola, Anders
, p. 1585 - 1590 (2009)
The nitrosyl complex [Cr(dmso)5(NO)](PF6)2 (1) (dmso = dimethyl sulfoxide) has been prepared by the solvolysis of [Cr(NCCH3)5(NO)](PF6)2 in neat dmso. The optical absorption spec
Near-UV Absorption Cross Sections and Trans/Cis Equilibrium of Nitrous Acid
Bongartz, A.,Kames, J.,Welter, F.,Schurath, U.
, p. 1076 - 1082 (1991)
The A 1A'' X 1A' absorption spectrum of gaseous nitrous acid has been measured in the 300-400-nm range.Absolute cross sections were determined by a combination of gas-phase and wet chemical analysis.The cross sections of prominent bands are 25percent larger than the recommended values of Stockwell and Calvert.The influence of spectral resolution on absolute and differential absorption cross sections was also investigated.The integrated band area of the n?* transition yields an oscillator strength f = (8.90 +/- 0.36) x 10-4, less than the reported liquid phase value of 2 x 10-3.The equilibrium constant K = ptrans/pcis, base d on the assumption that the oscillator strength of the n?* transition is the same for both rotamers, was found to be 3.25 +/- 0.30 at 277 K.This yields an energy difference ΔE between trans- and cis-HONO of -2700 J mol-1 in the electronic ground state, and -6000 J mol-1 in the excited state.
Role of OH-stretch/torsion coupling and quantum yield effects in the first OH overtone spectrum of cis-cis HOONO
McCoy, Anne B.,Fry, Juliane L.,Francisco, Joseph S.,Mollner, Andrew K.,Okumura, Mitchio
, (2005)
The effects of OH-stretch/HOON torsion coupling and of quantum yield on the first OH overtone spectrum of cis-cis HOONO were investigated. The direct absorption spectrum of cis-cis HOONO was recorded by cavity ringdown spectroscopy in a discahrge flow cell. A single band of HOONO is observed at 6370 cm-1 and is assigned as the origin of the first OH overtone of cis-cis HOONO. The results show that the coupling of the OH stretch to the HOON torsion and quantum yield effects are primarily responsible for the features seen in the action spectrum.
Experimental and theoretical study of the reaction of HO- with NO
Doren, Jane M. Van,Viggiano, A. A.,Morris, Robert A.,Miller, Amy E. Stevens,Miller, Thomas M.,et al.
, p. 7940 - 7950 (1993)
Hydroxide ion (HO-) reacts with nitric oxide by slow reactive electron detachment with a rate coefficient ca. 4 x 10-12 cm3 s-1 at 298 K.The detachment process is presumably associative detachment forming nitrous acid and an electron.Observations, data analysis, and alternative explanations for these observations are discussed.The associative detachment reaction was also investigated theoretically through calculations of the geometries, relative energies, and normal-mode vibrational frequencies of the relevant species HO-, HO, NO, cis- and trans-HONO, and cis- and trans-HONO-.These calculations indicate that in the ion HONO-, the cis conformer is more stable, while in the neutral HONO, the trans conformer is more stable.The HO-NO bond in HONO, which is formed in this reaction, is much stronger than the HO--NO bond in HONO- with an energy of 198.7+/-1.8 kJ mol-1 for cis HONO and 52.2+/-5 kJ mol-1 for cis-HONO- at 0 K.HONO- is bound with respect to HONO.The adiabatic electron detachment energy resulting from detachment from cis-HONO- forming the same conformer of the neutral molecule cis-HONO is 0.29+/-0.05 eV.The HO-NO equilibrium bond distance in HONO- is considerably longer than that in HONO, with values of 1.750 and 1.640 Angstroem for trans- and cis- HONO-, respectively, and 1.429 and 1.392 Angstroem for trans- and cis-HONO, respectively.These geometric and energetic characteristics of HONO- and HONO are combined with calculations of relative energies of these species at nonequilibrium/distorted HO-NO bond lengths to give a qualitative picture of the potential energy curves for these species along the reaction coordinate.While no significant energy barrier to autodetachment of HONO- is present, the Franck-Condon wave function overlap for aitodetachment is small and is likely the reason for the observed inefficiency.The maximum calculated rate constant for associative detachment is 4 x 10-12 cm3 s-1, in good agreement with the observed value.
