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1.
Ole J. Nielsen Matthew S. Johnson Timothy J. Wallington Lene K. Christensen Jesper Platz 《国际化学动力学杂志》2002,34(5):283-291
Pulse radiolysis techniques were used to measure the gas phase UV absorption spectra of the title peroxy radicals over the range 215–340 nm. By scaling to σ(CH3O2)240 nm = (4.24 ± 0.27) × 10?18, the following absorption cross sections were determined: σ(HO2)240 nm = 1.29 ± 0.16, σ(C2H5O2)240 nm = 4.71 ± 0.45, σ(CH3C(O)CH2O2)240 nm = 2.03 ± 0.22, σ(CH3C(O)CH2O2)230 nm = 2.94 ± 0.29, and σ(CH3C(O)CH2O2)310 nm = 1.31 ± 0.15 (base e, units of 10?18 cm2 molecule?1). To support the UV measurements, FTIR‐smog chamber techniques were employed to investigate the reaction of F and Cl atoms with acetone. The F atom reaction proceeds via two channels: the major channel (92% ± 3%) gives CH3C(O)CH2 radicals and HF, while the minor channel (8% ± 1%) gives CH3 radicals and CH3C(O)F. The majority (>97%) of the Cl atom reaction proceeds via H atom abstraction to give CH3C(O)CH2 radicals. The results are discussed with respect to the literature data concerning the UV absorption spectra of CH3C(O)CH2O2 and other peroxy radicals. © 2002 Wiley Periodicals, Inc. Int J Chem Kinet 34: 283–291, 2002 相似文献
2.
Products of the gas-phase reactions of OH radicals with O,O-diethyl methylphosphonothioate [(C2H5O)2P(S)CH3, DEMPT] and O,O,O-triethyl phosphorothioate [(C2H5O)3PS, TEPT] have been investigated at room temperature and atmospheric pressure of air using in situ atmospheric pressure ionization mass spectrometry (API-MS) and, for the TEPT reaction, gas chromatography and in situ Fourier transform infrared (FT-IR) spectroscopy. Combined with products quantified previously by gas chromatography, the products observed were: from the DEMPT reaction, (C2H5O)2P(O)CH3 (21+/-4% yield) and C2H5OP(S)(CH3)OH or C2H5OP(O)(CH3)SH (presumed to be C2H5OP(O)(CH3)SH by analogy with the TEPT reaction); and from the TEPT reaction, (C2H5O)3PO (54-62% yield), SO2 (67+/-10% yield), CH3CHO (22-40% yield) and, tentatively, (C2H5O)2P(O)SH. The FT-IR analyses showed that the formation yields of HCHO, CO, CO2, peroxyacetyl nitrate [CH3C(O)OONO2], organic nitrates, and acetates from the TEPT reaction were <5%, 3+/-1%, <7%, <2%, 5+/-3%, and 3+/-2%, respectively. Possible reaction mechanisms are discussed. 相似文献
3.
The reactions of CH3 radicals with O(3P) and O2 have been studied at 295 K in a gas flow reactor sampled by a mass spectrometer. For the reaction between CH3 and O, conditions were such that [O] » [CH3] and the methyl radicals decayed under pseudo-first-order conditions giving a rate coefficient of (1.14 ± 0.29) × 10?10 cm3/s. The reaction between CH3 and O2 was studied in separate experiments in which CH3 decayed under pseudo-first-order conditions. In this case, the rate coefficient obtained increased with increasing concentration of the helium carrier gas. This was varied over the range of 2.5–25 × 1016 cm?3, resulting in values for the apparent two-body rate coefficient ranging from 1 × 10?14 to 5.2 × 10?14 cm3/s. No evidence was found for the production of HCHO by a direct two-body process involving CH3 + O2, and an upper limit of 3 × 10?16 cm3/s was placed on the rate coefficient for this reaction. The experimental results for the apparent two-body rate coefficient exhibit the curvature one would expect for an association reaction in the fall-off region. Calculations used to extrapolate these measurements to the low-pressure limit yield a value for k0 of (3.4 ± 1.1) × 10?31 cm6/s, which is more than a factor of 2 higher than previous estimates. 相似文献
4.
The potential energy surfaces of H-atom reactions with CH(3)CH(2)O and CH(3)CHOH, two major radicals in the decomposition and oxidation of ethanol, have been studied at the CCSD(T)/6-311+G(3df,2p) level of theory with geometric optimization carried out at the BH&HLYP/6-311+G(3df,2p) level. The direct hydrogen abstraction channels and the indirect association/decomposition channels from the chemically activated ethanol molecule have been considered for both reactions. The rate constants for both reactions have been calculated at 100-3000 K and 10(-4) Torr to 10(3) atm Ar pressure by microcanonical VTST/RRKM theory with master equation solution for all accessible product channels. The results show that the major product channel of the CH(3)CH(2)O + H reaction is CH(3) + CH(2)OH under atmospheric pressure conditions. Only at high pressure and low temperature, the rate constant for CH(3)CH(2)OH formation by collisonal deactivation becomes dominant. For CH(3)CHOH + H, there are three major product channels; at high temperatures, CH(3)+CH(2)OH production predominates at low pressures (P < 100 Torr), while the formation of CH(3)CH(2)OH by collisional deactivation becomes competitive at high pressures and low temperatures (T < 500 K). At high temperatures, the direct hydrogen abstraction reaction producing CH(2)CHOH + H(2) becomes dominant. Rate constants for all accessible product channels in both systems have been predicted and tabulated for modeling applications. The predicted value for CH(3)CHOH + H at 295 K and 1 Torr pressure agrees closely with available experimental data. For practical modeling applications, the rate constants for the thermal unimolecular decomposition of ethanol giving key accessible products have been predicted; those for the two major product channels taking place by dehydration and C-C breaking agree closely with available literature data. 相似文献
5.
《Journal of organometallic chemistry》1987,323(1):C5-C9
The solution obtained by reduction of [(triphos)CO(μ-Cl)2Co(triphos)]+2 (triphos = CH3C(CH2PPh2)3) with Na/Hg reacts with CO2, CS2 and SO2 to give (triphos)Co(O2CO), (triphos)Co(S2CO), and (triphos)Co(O2SO), respectively. The molecular structure of the last has been established by X-ray difraction. 相似文献
6.
Jens Sehested Lene K. Christensen Ole J. Nielsen Merete Bilde Timothy J. Wallington William F. Schneider John J. Orlando Geoffrey S. Tyndall 《国际化学动力学杂志》1998,30(7):475-489
Pulse radiolysis was used to study the kinetics of the reactions of CH3C(O)CH2O2 radicals with NO and NO2 at 295 K. By monitoring the rate of formation and decay of NO2 using its absorption at 400 and 450 nm the rate constants k(CH3C(O)CH2O2+NO)=(8±2)×10−12 and k(CH3C(O)CH2O2+NO2)=(6.4±0.6)×10−12 cm3 molecule−1 s−1 were determined. Long path length Fourier transform infrared spectrometers were used to investigate the IR spectrum and thermal stability of the peroxynitrate, CH3C(O)CH2O2NO2. A value of k−6≈3 s−1 was determined for the rate of thermal decomposition of CH3C(O)CH2O2NO2 in 700 torr total pressure of O2 diluent at 295 K. When combined with lower temperature studies (250–275 K) a decomposition rate of k−6=1.9×1016 exp (−10830/T) s−1 is determined. Density functional theory was used to calculate the IR spectrum of CH3C(O)CH2O2NO2. Finally, the rate constants for reactions of the CH3C(O)CH2 radical with NO and NO2 were determined to be k(CH3C(O)CH2+NO)=(2.6±0.3)×10−11 and k(CH3C(O)CH2+NO2)=(1.6±0.4)×10−11 cm3 molecule−1 s−1. The results are discussed in the context of the atmospheric chemistry of acetone and the long range atmospheric transport of NOx. © John Wiley & Sons, Inc. Int J Chem Kinet: 30: 475–489, 1998 相似文献
7.
Based on an FTIR-product study of the photolysis of mixtures containing Br2? CH3CHO and Br2? CH3CHO? HCHO in 700 torr of N2, the rate constant for the reaction Br + CH3CHO → HBr + CH3CO was determined to be 3.7 × 10?12 cm3 molecule?1 s?1. In addition, the selective photochemical generation of Br at λ > 400 nm in mixtures containing Br2? CH3CHO? 14NO2 (or 15NO2)? O2 was shown to serve as a quantitative preparation method for the corresponding nitrogen-isotope labeled CH3C(O)OONO2 (PAN). From the dark-decay rates of 15N-labeled PAN in large excess 14NO2, the rate constant for the unimolecular reaction CH3C(O)OO15NO2 → CH3C(O)OO + 15NO2 was measured to be 3.3 (±0.2) × 10?4 s?1 at 297 ± 0.5 K. 相似文献
8.
Khamaganov V Karunanandan R Rodriguez A Crowley JN 《Physical chemistry chemical physics : PCCP》2007,9(31):4098-4113
The formation of CH(3) in the 248 or 266 nm photolysis of acetone (CH(3)C(O)CH(3)), 2-butanone (methylethylketone, MEK, CH(3)C(O)C(2)H(5)) and acetyl bromide (CH(3)C(O)Br) was examined using the pulsed photolytic generation of the radical and its detection by transient absorption spectroscopy at 216.4 nm. Experiments were carried out at room temperature (298 +/- 3 K) and at pressures between approximately 5 and 1500 Torr N(2). Quantum yields for CH(3) formation were derived relative to CH(3)I photolysis at the same wavelength in back-to-back experiments. For acetone at 248 nm, the yield of CH(3) was greater than unity at low pressures (1.42 +/- 0.15 extrapolated to zero pressure) confirming that a substantial fraction of the CH(3)CO co-product can dissociate to CH(3) + CO under these conditions. At pressures close to atmospheric the quantum yield approached unity, indicative of almost complete collisional relaxation of the CH(3)CO radical. Measurements of increasing CH(3)CO yield with pressure confirmed this. Contrasting results were obtained at 266 nm, where the yields of CH(3) (and CH(3)CO) were close to unity (0.93 +/- 0.1) and independent of pressure, strongly suggesting that nascent CH(3)CO is insufficiently activated to decompose on the time scales of these experiments at 298 K. In the 248 nm photolysis of CH(3)C(O)Br, CH(3) was observed with a pressure independent quantum yield of 0.92 +/- 0.1 and CH(3)CO remained below the detection limit, suggesting that CH(3)CO generated from CH(3)COBr photolysis at 248 nm is too highly activated to be quenched by collision. Similar to CH(3)C(O)CH(3), the photolysis of CH(3)C(O)C(2)H(5) at 248 nm revealed pressure dependent yields of CH(3), decreasing from 0.45 at zero pressure to 0.19 at pressures greater than 1000 Torr with a concomitant increase in the CH(3)CO yield. As part of this study, the absorption cross section of CH(3) at 216.4 nm (instrumental resolution of 0.5 nm) was measured to be (4.27 +/- 0.2) x 10(-17) cm(2) molecule(-1) and that of C(2)H(5) at 222 nm was (2.5 +/- 0.6) x 10(-18) cm(2) molecule(-1). An absorption spectrum of gas-phase CH(3)C(O)Br (210-305 nm) is also reported for the first time. 相似文献
9.
Rate constants for the reactions of OH radicals and NO3 radicals with O,O-diethyl methylphosphonothioate [(C(2)H(5)O)(2)P(S)CH(3); DEMPT] and O,O,O-triethyl phosphorothioate [(C(2)H(5)O)(3)PS; TEPT] have been measured using relative rate methods at atmospheric pressure of air over the temperature range 296-348 K for the OH radical reactions and at 296 +/- 2 K for the NO(3) radical reactions. At 296 +/- 2 K, the rate constants obtained for the OH radical reactions (in units of 10(-11) cm(3) molecule(-1) s(-1)) were 20.4 +/- 0.8 and 7.92 +/- 0.27 for DEMPT and TEPT, respectively, and those for the NO(3) radical reactions (in units of 10(-15) cm(3) molecule(-1) s(-1)) were 2.01 +/- 0.20 and 1.03 +/- 0.10, respectively. Upper limits to the rate constants for the reactions of O(3) with DEMPT and TEPT of <6 x 10(-20) cm(3) molecule(-1) s(-1) were determined in each case. Rate constants for the OH radical reactions, measured relative to k(OH + alpha-pinene) = 1.21 x 10(-11) e(436/T) cm(3) molecule(-1) s(-1), resulted in the Arrhenius expressions k(OH + DEMPT) = 1.08 x 10(-11) e(871+/-25)/T cm(3) molecule(-1) s(-1) and k(OH + TEPT) = 8.21 x 10(-13) e(1353+/-49)/T cm(3) molecule(-1) s(-1) over the temperature range 296-348 K, where the indicated errors are two least-squares standard deviations and do not include the uncertainties in the reference rate constant. Diethyl methylphosphonate was identified and quantified from the OH radical and NO(3) radical reactions with DEMPT, with formation yields of 21 +/- 4%, independent of temperature, from the OH radical reaction and 62 +/- 11% from the NO(3) radical reaction at 296 +/- 2 K. Similarly, triethyl phosphate was identified and quantified from the OH radical and NO(3) radical reactions with TEPT, with formation yields of 56 +/- 9%, independent of temperature, from the OH radical reaction and 78 +/- 15% from the NO(3) radical reaction at 296 +/- 2 K. 相似文献
10.
T. J. Wallington J. C. Ball A. M. Straccia M. D. Hurley E. W. Kaiser M. Dill W. F. Schneider M. Bilde 《国际化学动力学杂志》1996,28(8):627-635
The kinetics and mechanism of the gas-phase reaction of Cl atoms with CH2CO have been studied with a FTIR spectrometer/smog chamber apparatus. Using relative rate methods the rate of reaction of Cl atoms with ketene was found to be independent of total pressure over the range 1–700 torr of air diluent with a rate constant of (2.7 ± 0.5) × 10−10 cm3 molecule−1 s−1 at 295 K. The reaction proceeds via an addition mechanism to give a chloroacetyl radical (CH2ClCO) which has a high degree of internal excitation and undergoes rapid unimolecular decomposition to give a CH2Cl radical and CO. Chloroacetyl radicals were also produced by the reaction of Cl atoms with CH2ClCHO; no decomposition was observed in this case. The rates of addition reactions are usually pressure dependent with the rate increasing with pressure reflecting increased collisional stabilization of the adduct. The absence of such behavior in the reaction of Cl atoms with CH2CO combined with the fact that the reaction rate is close to the gas kinetic limit is attributed to preferential decomposition of excited CH2ClCO radicals to CH2Cl radicals and CO as products as opposed to decomposition to reform the reactants. As part of this work ab initio quantum mechanical calculations (MP2/6-31G(d,p)) were used to derive ΔfH298(CH2ClCO) = −(5.4 ± 4.0) kcal mol−1. © 1996 John Wiley & Sons, Inc. 相似文献
11.
Six product channels have been found in the association reaction of CN + CH2CO, and a variety of possible complexes and saddle points along the minimum energy reaction paths have been characterized at the UMP2(full)/6‐31G(d) level. The dominant reaction channels are the production of CH2CN + CO and CH2NC + CO. The isomerization and dissociation reactions of the major products of CH2CN and CH2NC have been investigated using the G2MP2 level. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2006 相似文献
12.
A kinetic study of the reactions of H atoms with CH3SH and C2H5SH has been carried out at 298 K by the discharge flow technique with EPR and mass spectrometric analysis of the species. The pressure was 1 torr. It was found: k1 = (2.20 ± 0.20) × 10?12 for the reaction H + CH3SH (1) and k2 = (2.40 ± 0.16) × 10?12 for the reaction H + C2H5SH (2). Units are cm3 molecule?1 s?1. A mass spectrometric analysis of the reaction products and a computer simulation of the reacting systems have shown that reaction (1) proceeds through two mechanisms leading to the formation of CH3S + H2 (1a) and CH3 + H2S (1b). 相似文献
13.
The kinetics of the reactions CH3O + Cl → H2CO + HCl (1) and CH3O + ClO → H2CO + HOCl (2) have been studied using the discharge-flow techniques. CH3O was monitored by laser-induced fluorescence, whereas mass spectrometry was used for the detection or titration of other species. The rate constants obtained at 298 K are: k1 = (1.9 ± 0.4) × 10−11 cm3 molecule−1 s−1 and k2 = (2.3 ± 0.3) × 10−11 cm3 molecule−1 s−1. These data are useful to interpret the results of the studies of the reactions of CH3O2 with Cl and ClO which, at least partly, produce CH3O radicals. © 1996 John Wiley & Sons, Inc. 相似文献
14.
Hao Sun Yi‐Zhen Tang Zhan‐Liang Wang Xiu‐Mei Pan Ze‐Sheng Li Rong‐Shun Wang 《International journal of quantum chemistry》2005,105(5):527-532
A detailed theoretical survey of the potential energy surface (PES) for the CH2CO + O(3P) reaction is carried out at the QCISD(T)/6‐311+G(3df,2p)//B3LYP/6‐311+G(d,p) level. The geometries, vibrational frequencies, and energies of all stationary points involved in the reaction are calculated at the B3LYP/6‐311+G(d,p) level. More accurate energy information is provided by single‐point calculations at the QCISD(T)/6‐311+G(3df,2p) level. Relationships of the reactants, transition states, intermediates, and products are confirmed by the intrinsic reaction coordinate (IRC) calculations. The results suggest that P1(CH2+CO2) is the most important product. This study presents highlights of the mechanism of the title reaction. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005 相似文献
15.
Le Crâne JP Villenave E Hurley MD Wallington TJ Ball JC 《The journal of physical chemistry. A》2005,109(51):11837-11850
The kinetics and mechanism of the reactions of Cl atoms and OH radicals with CH3CH2CHO were investigated at room temperature using two complementary techniques: flash photolysis/UV absorption and continuous photolysis/FTIR smog chamber. Reaction with Cl atoms proceeds predominantly by abstraction of the aldehydic hydrogen atom to form acyl radicals. FTIR measurements indicated that the acyl forming channel accounts for (88 +/- 5)%, while UV measurements indicated that the acyl forming channel accounts for (88 +/- 3)%. Relative rate methods were used to measure: k(Cl + CH3CH2CHO) = (1.20 +/- 0.23) x 10(-10); k(OH + CH3CH2CHO) = (1.82 +/- 0.23) x 10(-11); and k(Cl + CH3CH2C(O)Cl) = (1.64 +/- 0.22) x 10(-12) cm3 molecule(-1) s(-1). The UV spectrum of CH3CH2C(O)O2, rate constant for self-reaction, and rate constant for cross-reaction with CH3CH2O2 were determined: sigma(207 nm) = (6.71 +/- 0.19) x 10(-18) cm2 molecule(-1), k(CH3CH2C(O)O2 + CH3CH2C(O)O2) = (1.68 +/- 0.08) x 10(-11), and k(CH3CH2C(O)O2 + CH3CH2O2) = (1.20 +/- 0.06) x 10(-11) cm3 molecule(-1) s(-1), where quoted uncertainties only represent 2sigma statistical errors. The infrared spectrum of C2H5C(O)O2NO2 was recorded, and products of the Cl-initiated oxidation of CH3CH2CHO in the presence of O2 with, and without, NO(x) were identified. Results are discussed with respect to the atmospheric chemistry of propionaldehyde. 相似文献
16.
Eskola AJ Wojcik-Pastuszka D Ratajczak E Timonen RS 《Physical chemistry chemical physics : PCCP》2006,8(12):1416-1424
The kinetics of the reactions of CH2Br and CH2I radicals with O2 have been studied in direct measurements using a tubular flow reactor coupled to a photoionization mass spectrometer. The radicals have been homogeneously generated by pulsed laser photolysis of appropriate precursors at 193 or 248 nm. Decays of radical concentrations have been monitored in time-resolved measurements to obtain the reaction rate coefficients under pseudo-first-order conditions with the amount of O2 being in large excess over radical concentrations. No buffer gas density dependence was observed for the CH2I + O2 reaction in the range 0.2-15 x 10(17) cm(-3) of He at 298 K. In this same density range the CH2Br + O2 reaction was obtained to be in the third-body and fall-off area. Measured bimolecular rate coefficient of the CH2I + O2 reaction is found to depend on temperature as k(CH2I + O2)=(1.39 +/- 0.01)x 10(-12)(T/300 K)(-1.55 +/- 0.06) cm3 s(-1)(220-450 K). Obtained primary products of this reaction are I atom and IO radical and the yield of I-atom is significant. The rate coefficient and temperature dependence of the CH2Br + O2 reaction in the third-body region is k(CH2Br + O2+ He)=(1.2 +/- 0.2)x 10(-30)(T/300 K)(-4.8 +/- 0.3) cm6 s(-1)(241-363 K), which was obtained by fitting the complete data set simultaneously to a Troe expression with the F(cent) value of 0.4. Estimated overall uncertainties in the measured reaction rate coefficients are about +/-25%. 相似文献
17.
The kinetics of the reaction of CH3O with NO and the branching ratio for HCHO product formation, obtained as ΓHCHO = (Rate of HCHO formation) / (Rate of CH3O decay), have been studied using a discharge flow reactor. Laser induced fluorescence has been used to monitor the decay of the CH3O radical and the build-up of the HCHO product. Overall rate constants and product branching ratios were measured at room temperature over the pressure range of 0.72–8.5 torr He. Three reaction mechanisms were considered which differed in the routes of HCHO formation: (i) direct disproportionation; (ii) via an energized collision complex; or (iii) both reaction routes. It has been shown that data on the pressure dependence of the overall rate constant are not sufficient to distinguish between these mechanisms. In addition, an accurate value of Γ is required. Analysis of the available experimental data provided 0.0 and about 0.1 as the lower and upper limit for Γ, respectively. Since the rate constants derived for CH3ONO formation were not sensitive to the value assumed for Γ, k = (1.69 ± 0.69) × 10?29 cm6 molecule?2 s?1 and k = (2.45 ± 0.31) × 10?11 cm3 molecule?1 s?1 could be derived. The rate constant obtained for formaldehyde formation when extrapolated to zero pressure is k = (3.15 ± 0.92) × 10?12 cm3 molecule?1 s?1. © 1994 John Wiley & Sons, Inc. 相似文献
18.
Solvent-free Synthesis of Tetramethylammonium Salts: Synthesis and Characterization of [N(CH3)4]2[C2O4], [N(CH3)4][CO3CH3], [N(CH3)4][NO2], [N(CH3)4][CO2H], and [N(CH3)4][O2C(CH2)2CO2CH3] A general procedure to synthesize tetramethylammonium salts is presented. Several tetramethylammonium salts were prepared in a crystalline state by solvent-free reaction of trimethylamine and different methyl compounds at mild conditions: [N(CH3)4]2[C2O4] (cubic; a = 1 114.8(3) pm), [N(CH3)4][CO3CH3] (P21/n; a = 813.64(3), b = 953.36(3), c = 1 131.3(4) pm, β = 90.03(1)°), [N(CH3)4][NO2] (Pmmn; a = 821.2(4), b = 746.5(3), c = 551.5(2) pm), [N(CH3)4][CO2H] (Pmmn; a = 792.8(7), b = 791.7(3), c = 563.3(4) pm) and [N(CH3)4][O2C(CH2)2CO2CH3] (P21; a = 731.1(2), b = 826.4(3), c = 1 025.2(3) pm, β = 110.1(1)°). The tetramethylammonium salts were characterized by IR-spectroscopy and X-ray diffraction. The crystal structures of the methylcarbonate and the nitrite are described. 相似文献
19.
The rate constants for the reaction of CN with N2O and CO2 have been measured by the laser dissociation/laser-induced fluorescence (two-laser pump-probe) technique at temperatures between 300 and 740 K. The rate of CN + N2O was measurable above 500 K, with a least-squares averaged rate constant, k = 10−11.8±0.4 exp(−3560 ± 181/T) cm3/s. The rate of CN + CO2, however, was not measurable even at the highest temperature reached in the present work, 743 K, with [CO2] ⩽ 1.9 × 1018 molecules/cm3. In order to rationalize the observed kinetics, quantum mechanical calculations based on the BAC-MP4 method were performed. The results of these calculations reveal that the CN + N2O reaction takes place via a stable adduct NCNNO with a small barrier of 1.1 kcal/mol. The adduct, which is more stable than the reactants by 13 kcal/mol, decomposes into the NCN + NO products with an activation energy of 20.0 kcal/mol. This latter process is thus the rate-controlling step in the CN + N2O reaction. The CN + CO2 reaction, on the other hand, occurs with a large barrier of 27.4 kcal/mol, producing an unstable adduct NCOCO which fragments into NCO + CO with a small barrier of 4.5 kcal/mol. The large overall activation energy for this process explains the negligibly low reactivity of the CN radical toward CO2 below 1000 K. Least-squares analyses of the computed rate constants for these two CN reactions, which fit well with experimental data, give rise to for the temperature range 300–3000 K. 相似文献