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1.
Manganese(II) is oxidized by ozone in acid solution, k=(1.5±0.2)×103 M−1 s−1 in HClO4 and k=(1.8±0.2)×103M−1 s−1 in H2SO4. The plausible mechanism is an oxygen atom transfer from O3 to Mn2+ producing the manganyl ion MnO2+, which subsequently reacts rapidly with Mn2+ to form Mn(III). No free OH radicals are involved in the mechanism. The spectrum of Mn(III) was obtained in the wave length range 200–310 nm. The activation energy for the initial reaction is 39.5 kJ/mol. Manganese(III) is reduced by hydrogen peroxide to Mn(II) with k(Mn(III)+H2O2)=2.8×103M−1 s−1 at pH 0–2. The mechanism of the reaction involving formation of the manganese(II)-superoxide complex and reaction of H2O2 with Mn(IV) species formed due to reversible disproportionation of Mn(III), is suggested. © 1998 John Wiley & Sons, Inc. Int J Chem Kinet 30: 207–214, 1998. 相似文献
2.
The kinetics of the reactions OH + Br2 → HOBr + Br (1) and OD + Br2 → DOBr + Br (3) have been studied in the temperature range 230–360 K and at total pressure of 1 Torr of helium using the discharge‐flow mass spectrometric method. The following Arrhenius expressions were obtained either from the kinetics of product formation (HOBr, DOBr) in excess of Br2 over OH and OD or from the kinetics of Br2 consumption in excess of OH and OD: k1 = (1.8 ± 0.3) × 10−11 exp [(235 ± 50)/T] and k3 = (1.9 ± 0.2) × 10−11 exp [(220 ± 25)/T] cm3 molecule−1 s−1. For the reaction channels of the title reactions: OH + Br2 → BrO + HBr and OD + Br2 → BrO + DBr, the upper limits of the branching ratios were found to be 0.03 and 0.02 at T = 320 K, respectively. © 1999 John Wiley & Sons, Inc. Int J Chem Kinet 31: 698–704, 1999 相似文献
3.
《Journal of Photochemistry》1986,32(3):341-349
The interaction between the ground and excited states of 1,4-bis[2-(5-phenyloxazolyl)]-benzene and bromomethanes such as CBr4, CHBr3 and CH2Br2 were investigated in benzene. Distinct complex formation was not observed either in the ground state or in the excited states. The excited singlet and triplet states are deactivated by these bromomethanes. The triplet yield is increased on the addition of CHBr3 or CH2Br2, whereas it is decreased on the addition of CBr4. The fluorescence quenching rate constants kq at 23 °C were determined to be 1.6 × 1010 M−1 s−1, 3.6 × 108M−1s−1 and 2.4 × 107M−1s−1 for CBr4, CHBr3 and CH2Br2 respectively. The rate constants kST′ of the enhanced intersystem crossing associated with the fluorescence quenching were evaluated from emission—absorption flash photolysis experiments as 3.0 × 108 M−1s−1, 1.9 × 108 M−1s−1 and 5.1 × 107 M−1s−1 for CBr4, CHBr3 and CH2Br2 respectively. kST′ increases with increasing number of bromine atoms contained in the quencher, so that the enhanced intersystem crossing is due to the external heavy-atom effect of the quencher. The apparent triplet yield for the quenching system depends not only on kST′ but also on the rates of the other non-radiative processes. This is the reason why the apparent triplet yield does not necessarily increase on fluorescence quenching by bromomethanes. 相似文献
4.
A laser photolysis–long path laser absorption (LP‐LPLA) experiment has been used to determine the rate constants for H‐atom abstraction reactions of the dichloride radical anion (Cl2−) in aqueous solution. From direct measurements of the decay of Cl2− in the presence of different reactants at pH = 4 and I = 0.1 M the following rate constants at T = 298 K were derived: methanol, (5.1 ± 0.3)·104 M−1 s−1; ethanol, (1.2 ± 0.2)·105 M−1 s−1; 1‐propanol, (1.01 ± 0.07)·105 M−1 s−1; 2‐propanol, (1.9 ± 0.3)·105 M−1 s−1; tert.‐butanol, (2.6 ± 0.5)·104 M−1 s−1; formaldehyde, (3.6 ± 0.5)·104 M−1 s−1; diethylether, (4.0 ± 0.2)·105 M−1 s−1; methyl‐tert.‐butylether, (7 ± 1)·104 M−1 s−1; tetrahydrofuran, (4.8 ± 0.6)·105 M−1 s−1; acetone, (1.41 ± 0.09)·103 M−1 s−1. For the reactions of Cl2− with formic acid and acetic acid rate constants of (8.0 ± 1.4)·104 M−1 s−1 (pH = 0, I = 1.1 M and T = 298 K) and (1.5 ± 0.8) · 103 M−1 s−1 (pH = 0.42, I = 0.48 M and T = 298 K), respectively, were derived. A correlation between the rate constants at T = 298 K for all oxygenated hydrocarbons and the bond dissociation energy (BDE) of the weakest C‐H‐bond of log k2nd = (32.9 ± 8.9) − (0.073 ± 0.022)·BDE/kJ mol−1 is derived. From temperature‐dependent measurements the following Arrhenius expressions were derived: k (Cl2− + HCOOH) = (2.00 ± 0.05)·1010·exp(−(4500 ± 200) K/T) M−1 s−1, Ea = (37 ± 2) kJ mol−1 k (Cl2− + CH3COOH) = (2.7 ± 0.5)·1010·exp(−(4900 ± 1300) K/T) M−1 s−1, Ea = (41 ± 11) kJ mol−1 k (Cl2− + CH3OH) = (5.1 ± 0.9)·1012·exp(−(5500 ± 1500) K/T) M−1 s−1, Ea = (46 ± 13) kJ mol−1 k (Cl2− + CH2(OH)2) = (7.9 ± 0.7)·1010·exp(−(4400 ± 700) K/T) M−1 s−1, Ea = (36 ± 5) kJ mol−1 Finally, in measurements at different ionic strengths (I) a decrease of the rate constant with increasing I has been observed in the reactions of Cl2− with methanol and hydrated formaldehyde. © 1999 John Wiley & Sons, Inc. Int J Chem Kinet 31: 169–181, 1999 相似文献
5.
The kinetics and mechanisms of the reactions of aluminium(III) with pentane-2,4-dione (Hpd), 1,1,1-trifluoro pentane-2,4-dione (Htfpd) and heptane-3,5-dione (Hhptd) have been investigated in aqueous solution at 25°C and ionic strength 0.5 mol dm−3 sodium perchlorate. The kinetic data are consistent with a mechanism in which aluminium(III) reacts with the β-diketones by two pathways, one of which is acid independent while the second exhibits a second-order inverse-acid dependence. The acid-independent pathway is ascribed to a mechanism in which [Al(H2O)6]3+ reacts with the enol tautomers of Hpd, Htfpd, and Hhptd with rate constants of 1.7(±1.3)×10−2, 0.79(±0.21), and 7.5(±1.6)×10−3 dm3 mol−1 s−1, respectively. The inverse acid pathway is consistent with a mechanism in which [Al(H2O)5(OH)]2+ reacts with the enolate ions of Hpd, Htfpd, and Hhptd with rate constants of 4.32(±0.18)×106, 5.84(±0.24)×103, and 1.67(±0.05)×107 dm3 mol−1 s−1, respectively. An alternative formulation involves a pathway in which [Al(H2O)4(OH)2]+ reacts with the protonated enol tautomers of the ligands. This gives rate constants of 2.79(±0.12)×104, 3.86(±0.16)×105, and 8.98(±0.25)×103 dm3 mol−1 s−1 for reaction with Hpd, Htfpd, and Hhptd, respectively. Consideration of the kinetic data reported here together with data from the literature, suggest that [Al(H2O)5(OH)]2+ reacts by an associative or associative-interchange mechanism. © 1998 John Wiley & Sons, Inc. Int J Chem Kinet 30: 257–266, 1998. 相似文献
6.
The kinetics of the title reactions have been studied using the discharge-flow mass spectrometic method at 296 K and 1 torr of helium. The rate constant obtained for the forward reaction Br+IBr→I+Br2 (1), using three different experimental approaches (kinetics of Br consumption in excess of IBr, IBr consumption in excess of Br, and I formation), is: k1=(2.7±0.4)×10−11 cm3 molecule−1s−1. The rate constant of the reverse reaction: I+Br2→Br+IBr (−1) has been obtained from the Br2 consumption rate (with an excess of I atoms) and the IBr formation rate: k−1=(1.65±0.2)×10−13 cm3molecule−1s−1. The equilibrium constant for the reactions (1,−1), resulting from these direct determinations of k1 and k−1 and, also, from the measurements of the equilibrium concentrations of Br, IBr, I, and Br2, is: K1=k1/k−1=161.2±19.7. These data have been used to determine the enthalpy of reaction (1), ΔH298°=−(3.6±0.1) kcal mol−1 and the heat of formation of the IBr molecule, ΔHf,298°(IBr)=(9.8±0.1) kcal mol−1. © 1998 John Wiley & sons, Inc. Int J Chem Kinet 30: 933–940, 1998 相似文献
7.
The kinetics of the reaction between BrO3− and sulfite was studied by measuring the concentrations of [Br−] and [H+] both in buffered and in unbuffered solutions. A mechanism was applied for simulation of the experimental observations. Rate constants k1=(0.027±0.004) M−1s−1 and k2=(85±5) M−1s−1 were determined for the following reactions: \halign{\hfill $#$\hfill &\hfill\qquad\qquad #\cr 3\ \rm HSO_{3}\!^{-}+BrO_{3}\!^{-}\longrightarrow 3\ SO_{4}\!^{2-}+Br^{-}+3\ H^{+}& (1)\cr 3\ \rm H_{2}SO_{3}(\hbox{or}\ SO_{2.}\hbox{aq})+BrO_{3}\!^{-}\longrightarrow 3\ SO_{4}\!^{2-}+Br^{-}+6\ H^{+}& (2)\cr } Rate constant k1 was obtained directly from the experimental results on unbuffered reactions, where Reaction (1) was predominant. Rate constant k2 was obtained by computer fitting of [Br−] to the experimental values for buffered reactions, where the rate of Reaction (2) was about four times higher than that of Reaction (1). © 1998 John Wiley & Sons, Inc. Int J Chem Kinet 30: 869–874, 1998 相似文献
8.
《International Journal of Radiation Applications and Instrumentation. Part C. Radiation Physics and Chemistry》1988,31(3):319-324
The decay of Br-2 in Ar-purged or N2O-saturated aqueous solutions of KBr (0.01-1.0 M) in the pH range 1–7 has been re-examined using the techniques of pulse radiolysis and computer simulation. The dependence of the rate constant for the intrinsic decay of Br-2 on ionic strength (controlled by KBr) has been established; the values of k (Br-2 + Br-2) are (1.9 ± 0.1) × 109, (2.2 ± 0.3) × 109 and (2.4 ± 0.3) × 109 M-1 s-1 in the presence of 0.01, 0.1 and 1.0 M KBr, respectively, independent of pH between 2 and 7. The computer simulation of the decay of Br-2 has also generated, for the latter species, ϵ = 10,000 ± 700 M-1 cm-1 at λmax = 360 nm; this value has been calculated without making any assumption concerning G(Br-2). For the reduction of Br-2 by H atoms, a value of k (H + Br-2) = (1.4 ± 0.3) × 1010 M-1 s-1 has been obtained in the presence of 0.01-1.0 M KBr, independent of pH between 1–4. For the reduction of Br-2 by e-aq at pH 7 (10-3 M phosphates) and μ = 0.1, a value of k (Br-2 + e-aq = (1.1 ± 0.2) × 1010 M-1 s-1 has been obtained. 相似文献
9.
《Chemical physics letters》1987,139(1):72-76
In the flash photolysis of SiBr4 both the absorption and the emission spectra corresponding to the B̃2Σ−X̃2Π transition of SiBr have been observed. A broad, structureless absorption band has also been detected in the 340–400 nm region which could be assigned to the hitherto unreported à 1B1−x̃ 1A1 transition of SiBr2. The decay of both absorption spectra followed first-order kinetics yielding the pseudo-first-order rate constants: k(SiBr)=2.6 × 104s−1 and k(SiBr2) = 8.9 × 103−1. Assuming that the principal reactions consuming these intermediates are SiBr+SiBr4→Si2Br5 and SiBr2+SiBr4→ Si2Br6, the second-order rate constants have the values k(SiBr)= 9.7×109 M−1s−1 and k(SiBr2)= 3.3×108M−1s−1. 相似文献
10.
The temperature dependence of the rate coefficients for the OH radical reactions with iso-propyl acetate (k1), iso-butyl acetate (k2), sec-butyl acetate (k3), and tert-butyl acetate (k4) have been determined over the temperature range 253–372 K. The Arrhenius expressions obtained are: k1=(0.30±0.03)×10−12 exp[(770±52)/T]; k2=(109±0.14)×10−12 exp[(534±79)/T]; k3=(0.73±0.08)×10−12 exp[(640±62)/T]; and k4=(22.2±0.34)×10−12 exp[−(395±92)/T] (in units of cm3 molecule−1 s−1). At room temperature, the rate constants obtained (in units of 10−12 cm3 molecule−1 s−1) were as follows: iso-propyl acetate (3.77±0.29); iso-butyl acetate (6.33±0.52); sec-butyl acetate (6.04±0.58); and tert-butyl acetate (0.56±0.05). Our results are compared with the previous determinations and discussed in terms of structure-activity relationships. © 1997 John Wiley & Sons, Inc. Int J Chem Kinet: 29: 683–688, 1997. 相似文献
11.
The presence of ceric and bromide ions catalyzes the isomerization of maleic acid (MA) to fumaric acid (FA) in aqueous sulfuric acid. A kinetic study of this bromine-catalyzed reaction was carried out. The reaction between ceric ion and maleic acid is first order with respect to Ce(IV). For [Ce(IV)]0=5.0×10?4 M, [H2SO4]0=1.2 M, μ=2.0 M (adjusted by NaClO4), and [MA]0=(0.5–1.0)M, the observed pseudo-first-order rate constant (k03) at 25° is k03=7.622×10?5 [MA]0/(1+0.205[MA]0). The reaction between ceric and bromide ions is first order with respect to Ce(IV). For [Ce(IV)]0=5.0×10?4 M, [H2SO4]0=1.2 M, μ=2.0 M, and [Br?]0=(0.025–0.150)M, the pseudo-first-order rate constant (k02) at 25° is k02= (4.313±0.095)x10?2[Br?]2+(2.060±0.119)x10?3[Br?]. The reaction of Ce(IV) with maleic acid and bromide ion is also first order with respect to Ce(IV). For [Ce(IV)]0=5.0×10?4 M, [MA]0=0.75 M, [H2SO4]0=1.2 M, μ=2.0 M, and [Br?]0= (0.025–0.150)M, the pseudo-first-order rate constant (k03) at 25° is k03= (5.286±0.045)x10?2[Br?]2+(3.568±0.056)x10?3[Br?]. For [Ce(IV)]0=5.0 × 10?4 M, [Br?]0=0.050 M, [H2SO4]0=1.2 M, μ=2.0 M, and [MA]0=(0.15–1.0)M at 25°, k03=(2.108×10?4+2.127×10?4[MA]0)/(1+0.205[MA]0). A mechanism is proposed to rationalize the results. The effect of temperature on the reaction rate was also studied. The energy barrier of Ce(IV)—Br? reaction is much less than that of Ce(IV)—MA reaction. Maleic and fumaric acids have very different mass spectra. The mass spectrum of fumaric acid exhibits a strong metastable peak at m/e 66.5. 相似文献
12.
《Chemical physics letters》1987,134(4):347-349
Reactions of CF2 carbene, generated by infrared CO2 laser photolysis of CHClF2, with Br2, Cl2 and H2 were investigated using infrared diode laser spectroscopy. Absolute rate constants at about 550 K for the reactions with Br2 and Cl2 were found to be (2.7 ± 0.9) × 10−15and (3.5 ± 1.3) × 10−15 cm3 molecule−1 s−1, respectively. No reaction was observed with H2. 相似文献
13.
Base hydrolysis reactions of [Cr(tmpa)(NCSe)]2O2+, [Cr(tmpa)(N3)]2O2+, [Cr2(tmpa)2(μ−O)(μ−PhPO4)]4+ and [Cr2(tmpa)2(μ−O)(μ−CO3)]2+ follow the pseudo‐first‐order relationship (excess OH−): kobsd=ko+kbQp[OH−]/(1+Qp[OH−]). For the CO32− complex, kb(60°C)=(1.50±0.03)×10−2 s−1; ΔH‡=61±2 kJ/mol, ΔS‡=−99±7 J/mol K; Qp(60°C)=(3.8±0.3)×101 M−1; ΔH°=67±2 kJ/mol, ΔS°=230±7 J/mol K (I=1.0 M). An isokinetic relationship among kOH(=kbQp) activation parameters for five (tmpa)CrOCr(tmpa) complexes shows that all follow essentially the same pathway. Activated complex formation is thought to require nucleophilic attack of coordinated OH− at the chromium‐leaving group bond in the kb step, accompanied by reattachment of a tmpa pyridyl arm displaced by OH− in the Qp preequilibrium. Abstraction of both thiocyanate ligands was observed upon mixing [Cr(tmpa)(NCS)]2O2+ with [Pd(CH3CN)4]2+ in CH3CN solution. The proposed mechanism requires rapid complexation of both reactant thiocyanate ligands by Pd(II) (Kp(25°C)=(4.5±0.2)×108 M−2; ΔH°=−32±6 kJ/mol, ΔS°=59±19 J/mol K) prior to rate‐limiting Cr NCS bond‐breaking (k2(25°C)=(1.17±0.02)×10−3 s−1; ΔH‡=98±2 kJ/mol, ΔS‡=27±5 J/mol K). Pd(II)‐assisted NCS− abstraction is not driven by weakening of the Cr( )NCS− bond through ligation of the sulfur atom to palladium, but rather by a favorable ΔS‡ resulting from the release of Pd(NCS)+ fragments and weak solvation of the activated complex in CH3CN solution. © 1999 John Wiley & Sons, Inc. Int J Chem Kinet 31: 351–356, 1999 相似文献
14.
Rate constants for the reactions of OH, NO3, and O3 with pinonaldehyde and the structurally related compounds 3-methylbutanal, 3-methylbutan-2-one, cyclobutyl-methylketone, and 2,2,3-trimethyl-cyclobutyl-1-ethanone have been measured at 300±5 K using on-line Fourier transform infrared spectroscopy. The rate constants obtained for the reactions with pinonaldehyde were: kOH=(9.1±1.8)×10−11 cm3 molecule−1 s−1, kNO3=(5.4±1.8)×10−14 cm3 molecule−1 s−1, and kO3=(8.9±1.4)×10−20 cm3 molecule−1 s−1. The results obtained indicate a chemical lifetime of pinonaldehyde in the troposphere of about two hours under typical daytime conditions, [OH]=1.6×106 molecule cm−3. © 1997 John Wiley & Sons, Inc. Int J Chem Kinet 29: 527–533, 1997. 相似文献
15.
G. S. Tyndall J. J. Orlando C. S. Kegley‐Owen T. J. Wallington M. D. Hurley 《国际化学动力学杂志》1999,31(11):776-784
Rate coefficients have been measured for the reactions of Cl atoms with methanol (k1) and acetaldehyde (k2) using both absolute (laser photolysis with resonance fluorescence) and relative rate methods at 295 ± 2 K. The measured rate coefficients were (units of 10−11 cm3 molecule−1 s−1): absolute method, k1 = (5.1 ± 0.4), k2 = (7.3 ± 0.7); relative method k1 = (5.6 ± 0.6), k2 = (8.4 ± 1.0). Based on a critical evaluation of the literature data, the following rate coefficients are recommended: k1 = (5.4 ± 0.9) × 10−11 and k2 = (7.8 ± 1.3) × 10−11 cm3 molecule−1 s−1 (95% confidence limits). The results significantly improve the confidence in the database for reactions of Cl atoms with these oxygenated organics. Rate coefficients were also measured for the reactions of Cl2 with CH2OH, k5 = (2.9 ± 0.6) × 10−11 and CH3CO, k6 = (4.3 ± 1.5) × 10−11 cm3 molecule−1 s−1, by observing the regeneration of Cl atoms in the absence of O2. Based on these results and those from a previous relative rate study, the rate coefficient for CH3CO + O2 at the high pressure limit is estimated to be (5.7 ± 1.9) × 10−12 cm3 molecule−1 s−1. © 1999 John Wiley & Sons, Inc. Int J Chem Kinet 31: 776–784, 1999 相似文献
16.
James B. Burkholder 《国际化学动力学杂志》1998,30(8):571-576
The room temperature rate coefficient for the reaction Br+Br2O→Br2+BrO (3) has been measured using the technique of pulse-laser photolysis with long-path transient absorption detection of the BrO reaction product. A value of k3=(2.0±0.5)×10−10 cm3 molecule−1 s−1 was determined. The photolysis products of Br2O at 308 nm were also examined. © 1998 John Wiley & Sons, Inc. Int J Chem Kinet 30: 571–576, 1998 相似文献
17.
Using a relative rate method, rate constants for the gas-phase reactions of 2-methyl-3-buten-2-ol (MBO) with OH radicals, ozone, NO3 radicals, and Cl atoms have been investigated using FTIR. The measured values for MBO at 298±2 K and 740±5 torr total pressure are: kOH=(3.9±1.2)×10−11 cm3 molecule−1 s−1, kO3=(8.6±2.9)×10−18 cm3 molecule−1 s−1, k=(8.6±2.9)×10−15 cm3 molecule−1 s−1, and kCl=(4.7±1.0)×10−10 cm3 molecule−1 s−1. Atmospheric lifetimes have been estimated with respect to the reactions with OH, O3, NO3, and Cl. The atmospheric relevance of this compound as a precursor for acetone is, also, briefly discussed. © 1998 John Wiley & Sons, Inc. Int J Chem Kinet: 30: 589–594, 1998 相似文献
18.
I. Morozov S. Gligorovski P. Barzaghi D. Hoffmann Y. G. Lazarou E. Vasiliev H. Herrmann 《国际化学动力学杂志》2008,40(4):174-188
Laser flash photolysis combined with competition kinetics with SCN? as the reference substance has been used to determine the rate constants of OH radicals with three fluorinated and three chlorinated ethanols in water as a function of temperature. The following Arrhenius expressions have been obtained for the reactions of OH radicals with (1) 2‐fluoroethanol, k1(T) = (5.7 ± 0.8) × 1011 exp((?2047 ± 1202)/T) M?1 s?1, (2) 2,2‐difluoroethanol, k2(T) = (4.5 ± 0.5) × 109 exp((?855 ± 796)/T) M?1 s?1, (3) 2,2,2‐trifluoroethanol, k3(T) = (2.0 ± 0.1) × 1011 exp((?2400 ± 790)/T) M?1 s?1, (4) 2‐chloroethanol, k4(T) = (3.0 ± 0.2) × 1010 exp((?1067 ± 440)/T) M?1 s?1, (5) 2, 2‐dichloroethanol, k5(T) = (2.1 ± 0.2) × 1010 exp((?1179 ± 517)/T) M?1 s?1, and (6) 2,2,2‐trichloroethanol, k6(T) = (1.6 ± 0.1) × 1010 exp((?1237 ± 550)/T) M?1 s?1. All experiments were carried out at temperatures between 288 and 328 K and at pH = 5.5–6.5. This set of compounds has been chosen for a detailed study because of their possible environmental impact as alternatives to chlorofluorocarbon and hydrogen‐containing chlorofluorocarbon compounds in the case of the fluorinated alcohols and due to the demonstrated toxicity when chlorinated alcohols are considered. The observed rate constants and derived activation energies of the reactions are correlated with the corresponding bond dissociation energy (BDE) and ionization potential (IP), where the BDEs and IPs of the chlorinated ethanols have been calculated using quantum mechanical calculations. The errors stated in this study are statistical errors for a confidence interval of 95%. © 2008 Wiley Periodicals, Inc. Int J Chem Kinet 40: 174–188, 2008 相似文献
19.
Yuri Bedjanian 《国际化学动力学杂志》2020,52(5):310-318
Kinetics of the reaction of Cl atoms with methanol has been investigated at 2 Torr total pressure of helium and over a wide temperature range 225-950 K, using a discharge flow reactor combined with an electron impact ionization quadrupole mass spectrometer. The rate constant of the reaction Cl + CH3OH → products (1) was determined using both absolute measurements under pseudo-first order conditions, monitoring the kinetics of Cl-atom consumption in excess of methanol and relative rate method, k1 = (5.1 ± 0.8) × 10−11 cm3 molecule−1 s−1, and was found to be temperature independent over the range T = 225-950 K. The rate constant of the reaction Cl + Br2 → BrCl + Br (3) was measured in an absolute way monitoring Cl-atom decays in excess of Br2: k3 = 1.64 × 10−10 exp(34/T) cm3 molecule−1 s−1 at T = 225-960 K (with conservative 15% uncertainty). The experimental data for k3 can also be adequately represented by the temperature independent value of k3 = (1.8 ± 0.3) × 10−10 cm3 molecule−1 s−1. The kinetic data from the present study are compared with previous measurements. 相似文献
20.
The kinetics of the gas-phase reactions of OH radicals, NO3 radicals, and O3 with indan, indene, fluorene, and 9,10-dihydroanthracene have been studied at 297 ± 2 K and atmospheric pressure of air. The rate constants, or upper limits thereof, for the O3 reactions were (in cm3 molecule−1 s−1 units): indan, < 3 × 10−19; indene, (1.7 ± 0.5) × 10−16, fluorene, < 2 × 10−19; and 9,10-dihydroanthracene, (9.0 ± 2.0) × 10−19. Using a relative rate method, the rate constants for the OH radical and NO3 radical reactions, respectively, were (in cm3 molecule−1 s−1 units): indan, (1.9 ± 0.5) × 10−11 and (6.6 ± 2.0) × 10−15; indene, (7.8 ± 2.0) × 10−11 and (4.1 ± 1.5) × 10−12; fluorene, (1.6 ± 0.5) × 10−11 and (3.5 ± 1.2) × 10−14; and 9,10-dihydroanthracene, (2.3 ± 0.6) × 10−11 and (1.2 ± 0.4) × 10−12. These kinetic data were used to assess the relative contributions of the various reaction pathways. © 1997 John Wiley & Sons, Inc. Int J Chem Kinet 29: 299–309, 1997. 相似文献