10102-03-1Relevant articles and documents
Heterogeneous kinetics of the uptake of ClONO2 on NaCl and KBr
Caloz, Francois,Fenter, Frederick F.,Rossi, Michel J.
, p. 7494 - 7501 (1996)
The uptake kinetics of ClONO2 on NaCl (reaction 1) and on KBr (reaction 2) have been studied in a low-pressure, Teflon-coated Knudsen reactor at room temperature. The initial uptake coefficient for both reactions has been measured as 0.23 ± 0.06 and 0.35 ± 0.06 for reactions 1 and 2, respectively, and is independent of reactant density in the range 1010-1013 molecules cm-3. The values of the uptake coefficients are independent of presentation of the salt substrates: identical results are obtained on powder, grains, single-crystal surfaces, and thin deposited salt layers. The only product of reaction 1 is Cl2. Reaction 2 initially produces Br2, followed by BrCl and Cl2. In our proposed mechanism, BrCl is the product of reaction 2, and secondary reactions between BrCl and the KBr substrate yield Br2 at short reaction times and Cl2 under prolonged exposure.
Metal oxidation with N2O5: The nitrosylium nitrates (NO)Cu(NO3)3, (NO)2[Zn(NO3) 4] and (NO)6[Ni4(NO3) 12](NO3)2·(HNO3)
Gagelmann, Steffen,Riess, Katja,Wickleder, Mathias S.
, p. 5160 - 5166 (2011)
The oxidation of copper, zinc and nickel by N2O5 led, respectively, to turquoise-coloured single crystals of (NO)Cu(NO 3)3 [monoclinic, P21/m, Z = 2, a = 465.90(5), b = 1111.7(1), c = 700.7(1) pm, β = 100.70(2)°, wR2 = 0.0566], light-yellow single crystals of (NO)2[Zn(NO 3)4] [orthorhombic, Fdd2, Z = 8, a = 1522.8(2), b = 2346.4(3), c = 596.18(7) pm, wR2 = 0.0452] and green single crystals of (NO)6[Ni4(NO3)12](NO 3)2·(HNO3) [orthorhombic, P2 12121, Z = 4, a = 1167.68(4), b = 1791.97(6), c = 1834.11(6) pm, wR2 = 0.0762]. In (NO)Cu(NO3) 3, the Cu2+ ion is coordinated by six oxygen atoms of monodentatenitrate groups in the form of a tetragonal distorted octahedron. The nitrate groups are connected to further copper ions leading to a two-dimensional network. In contrast, in (NO)2[Zn(NO3)4], the nitrate anions are coordinated to only one Zn2+, ion and the coordination polyhedron is a distorted octahedron. The complex nitrate (NO) 6[Ni4(NO3)12](NO3) 2·(HNO3) exhibits anionic ribbon chains according to ∞1{[Ni(NO3)1/1(NO 3)4/2]}22- with octahedrally coordinated Ni2+ ions as well as non-coordinating nitrate ions and HNO3 molecules. The thermal decomposition of the copper and zinc nitrates are multistep processes and lead to a mixture of Cu and Cu2O in the case of the copper compound and to ZnO for the zinc complex. Copyright
Infrared spectrum and theoretical study of the dinitrogen pentoxide molecule (N2O5) in solid argon
Bencivenni,Sanna,Schriver-Mazzuoli,Schriver
, p. 7836 - 7846 (1996)
Fourier Transform Infrared (FTIR) spectra of the covalent dinitrogen pentoxide molecule isolated in a solid argon matrix at 10 K are reported. The measured frequencies in the 200-4000 cm-1 region are in close agreement with gas phase values previously reported. An accurate and sophisticated ab initio study showed that the stable equilibrium structure, C2 symmetry, was in agreement with the structure previously determined by electron diffraction data.
Temperature-Dependent Ultraviolet Absorption Spectrum for Dinitrogen Pentoxide
Yao, Francis,Wilson, Ivan,Johnston, Harold
, p. 3611 - 3615 (1982)
The ultraviolet absorption cross sections for N2O5 are presented for wavelengths between 200 and 380 nm and for temperatures between 223 and 300 K.The absorption spectrum above 290 nm shows a pronounced temperature dependence.
Heterogeneous uptake of gaseous N2O5 by (NH4)2SO4, NH4HSO4, and H2SO4 aerosols
Kane, Sean M.,Caloz, Francois,Leu, Ming-Taun
, p. 6465 - 6470 (2001)
The heterogeneous uptake of gaseous N2O5 by ammonium sulfate [(NH4)2SO4], ammonium bisulfate [NH4HSO4], and sulfuric acid [H2SO4] aerosols as a function of relative humidity has been investigated at room temperature and atmospheric pressure. Ammonium-containing aerosols were generated by a constant-output atomizer and conditioned by passing through a diffusion dryer. Sulfuric acid aerosols were produced by the homogeneous reaction of SO3 and H2O in a borosilicate vessel. Addition of a dry or wet N2 flow controlled the relative humidity (RH) of these aerosol flows. Using a chemical ionization mass spectrometer (CIMS) for N2O5 concentration monitoring and a scanning mobility particle spectrometer (SMPS) for aerosol characterization, reaction probabilities (γ) in the range of 0.001 to 0.1 for the uptake of N2O5 were determined as a function of RH. The results are expressed as follows: γ[(NH4)2SO4] = 2.79 × 10-4 + 1.30 × 10-4 × (RH) - 3.43 × 10-6 × (RH)2 + 7.52 × 10-8 × (RH)3, γ[NH4HSO4] = 2.07 × 10-3 - 1.48 × 10-4 × (RH) + 8.26 × 10-6 × (RH)2, and γ[H2SO4] = 0.052 - 2.79 × 10-4 × (RH). We suggest that the water content and phase in the ammonium-containing aerosols control the reactivity of N2O5 while liquid-phase ionic reactions primarily dominate the uptake in sulfuric acid aerosols.
Nitrate radical quantum yield from peroxyacetyl nitrate photolysis
Flowers, Bradley A.,Angerhofer, Mark E.,Simpson, William R.,Nakayama, Tomoki,Matsumi, Yutaka
, p. 2552 - 2558 (2005)
Peroxyacetyl nitrate (PAN, CH3C(O)OONO2) is a ubiquitous pollutant that is primarily destroyed by either thermal or photochemical mechanisms. We have investigated the photochemical destruction of PAN using a combination of laser pulsed photolysis and cavity ring-down spectroscopic detection of the NO3 photoproduct. We find that the nitrate radical quantum yield from the 289 nm photolysis of PAN is φNO3PAN = 0.31 ± 0.08 (±2σ). The quantum yield is determined relative to that of dinitrogen pentoxide, which is assumed to be unity, under identical experimental conditions. The instrument design and experimental procedure are discussed as well as auxiliary experiments performed to further characterize the performance of the optical cavity and photolysis system.
Reactive uptake of N2O5 on aqueous H 2so4 solutions coated with 1-component and 2-component monolayers
Cosman,Bertram
, p. 4625 - 4635 (2008)
Reactive uptake of N2O5 on aqueous sulfuric acid solutions was studied in the presence of 1-component (octadecanol) and 2-component (octadecanol + phytanic acid) monolayers. In the 1-component monolayer experiments, the reactive uptake coefficient depended strongly on the molecular surface area of the surfactant. Also, the 1-component monolayer showed significant resistance to mass transfer even when the fractional surface coverage of the surfactant was less than 1. For example, a monolayer of 1-octadecanol with a fractional surface coverage of 0.75 decreased the reactive uptake coefficient by a factor of 10. This is consistent with previous studies. In the 2-component monolayer experiments, the reactive uptake coefficient depended strongly on the composition of the monolayer. When the monolayer contained only straight-chain molecules (1-octadecanol), the reactive uptake coefficient decreased by a factor of 42 due to the presence of the monolayer. However, when the monolayer contained 0.20 mole fraction of a branched surfactant (phytanic acid) the reactive uptake coefficient only decreased by a factor of 2. Hence, a small amount of branched surfactant drastically changes the overall resistance to reactive uptake. Also, our results show that the overall resistance to reactive uptake of 2-component monolayers can be predicted reasonably accurately by a model that assumes the resistances to mass transfer can be combined in parallel.
Kinetics of ClONO2 reactive uptake on ice surfaces at temperatures of the upper troposphere
Fernandez, Miguel A.,Hynes, Robert G.,Cox, Richard A.
, p. 9986 - 9996 (2005)
The reactive uptake kinetics of ClONO2 on pure and doped water-ice surfaces have been studied using a coated wall flow tube reactor coupled to an electron impact mass spectrometer. Experiments have been conducted on frozen film ice surfaces in the temperature range 208-228 K with P ClONO2 ≤ 10-6 Torr. The uptake coefficient (γy) of ClONO2 on pure ice was time dependent with a maximum value of γmax ～0.1. On HNO3-doped ice at 218 K the γmax was 0.02. HOCl formation was detected in both experiments. On HCl-doped ice, uptake was gas-phase diffusion limited (γ > 0.1) and gas-phase Cl2 was formed. The uptake of HCl on ice continuously doped with HNO3 was reversible such that there was no net uptake of HCl once the equilibrium surface coverage was established. The data were well described by a single site 2-species competitive Langmuir adsorption isotherm. The surface coverage of HCl on HNO3-doped ice was an order of magnitude lower than on bare ice for a given temperature and PHCl. ClONO2 uptake on this HCl/HNO3-doped ice was studied as a function of PHClHci. γmax was no longer gas-phase diffusion limited and was found to be linearly dependent on the surface concentration of HCl. Under conditions of low HCl surface concentration, hydrolysis of ClONO2 and reaction with HCl were competing such that both Cl2 and HOCl were formed. A numerical model was used to simulate the experimental results and to aid in the parametrization of ClONO2 reactivity on cirrus ice clouds in the upper troposphere.
Rate Constants for Reactions between Atmospheric Reservoir Species. 1. HCl
Leu, Ming-Taun,Hatakeyama, Shiro,Hsu, Kuang-Jung
, p. 5778 - 5784 (1989)
The kinetics of the reactions of HCl with ClONO2, N2O5, O3, and HO2NO2 have been investigated by using a large-volume static reactor and a Fourier transform spectrometer (FTIR) at 296 K.The upper limits for the homogenous gas-phase reaction rates of the ClONO2 + HCl, N2O5 + HCl, O3 + HCl, and HO2NO2 + HCl reactions were found to be 8.4 x 10-21, 8.4 x 10-21, 4.7 x 10-24, and 9.0 x 10-22 (all in unit of cm3 s-1), respectively.The heterogeneous nature of the ClONO2 + HCl and N2O5 + HCl reactions are characterized in terms of the Langmuir-Rideal mechanism.The yields of HNO3 were be observed to be 0.94 +/- 0.14 and 1.10 +/- 0.12 for the ClONO2 + HCl and N2O5 + HCl reactions, respectively, and the yield of ClNO2 was found to be 0.84 +/- 0.10 for the N2O5 + HCl reaction.The quoted errors represent one standard deviation of the measurement.In addition, an upper limit of 1.6 x 10-19 cm3 s-1 at 296 K for the reaction of NO3 with HCl was also obtained in this study.These results may be important in the elucidation of the role played by heterogeneous reactions in the development of the springtime Antarctic ozone depletion over the past decade.
A Fourier Transform Infrared Study of the Rate Constant of the Homogeneous Gas-Phase Reaction N2O5 + H2O and Determination of Absolute Infrared Band Intensities of N2O5 and HNO3
Hjorth, J.,Ottobrini, G.,Cappellani, F.,Restelli, G.
, p. 1565 - 1568 (1987)
N2O5 was reacted with water vapor in large FEP-Teflon bags and its decay followed by samplig in a White gas cell using infrared Fourier transform spectroscopy.A rate constant for the homogeneous N2O5 + H2O gas-phase reaction at 296 +/- 2 K and 740 Torr total pressure equel to (1.48 +/- 0.42)E-21 cm3/molecule*s was observed.Critical analysis of the results suggested that the true homogeneous rate constant might be lower.The measured HNO3 absolute intensities of the overlapping band systes $v5, 2$v9 and $v5 + $v9 - $v9 (840-930/cm) and $v3,$v4 (1270-1350/cm) were 2.21E-17 and 4.29E-17 cm/molecule, respectively.
