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1.
SHAOLIANG ZHANG RAFAL STREKOWSKI ANNE MONOD LOÏC BOSLAND CORNELIUS ZETZSCH 《国际化学动力学杂志》2014,46(9):554-566
A flash photolysis–resonance fluorescence technique was used to investigate the kinetics of the OH(X2Π) radical and O(3P) atom‐initiated reactions with CHI3 and the kinetics of the O(3P) atom‐initiated reaction with C2H5I. The reactions of the O(3P) atom with CHI3 and C2H5I were studied over the temperature range of 296 to 373 K in 14 Torr of helium, and the reaction of the OH (X2Π) radical with CHI3 was studied at T = 298 K in 186 Torr of helium. The experiments involved time‐resolved resonance fluorescence detection of OH (A2Σ+ → X2Π transition at λ = 308 nm) and of O(3P) (λ = 130.2, 130.5, and 130.6 nm) following flash photolysis of the H2O/He, H2O/CHI3/He, O3/He, and O3/C2H5I/He mixtures. A xenon vacuum UV (VUV) flash lamp (λ > 120 nm) served as a photolysis light source. The OH radicals were produced by the VUV flash photolysis of water, and the O(3P) atoms were produced by the VUV flash photolysis of ozone. Decays of OH radicals and O(3P) atoms in the presence of CHI3 and C2H5I were observed to be exponential, and the decay rates were found to be linearly dependent on the CHI3 and C2H5I concentrations. Measured rate coefficients for the reaction of O(3P) atoms with CHI3 and C2H5I are described by the following Arrhenius expressions (units are cm3 s?1): kO+C2H5I(T) = (17.2 ± 7.4) × 10?12 exp[?(190 ± 140)K/T] and kO+CHI3(T) = (1.80 ± 2.70) × 10?12 exp[?(440 ± 500)K/T]; the 298 K rate coefficient for the reaction of the OH radical with CHI3 is kOH+CHI3(298 K) = (1.65 ± 0.06) × 10?11 cm3 s?1. The listed uncertainty values of the Arrhenius parameters are 2σ‐standard errors of the calculated slopes by linear regression. 相似文献
2.
A novel binuclear praseodymium(III) complex with N-(2-propionyl)salicyloylhydrazone (C10H10N2O4, H3L) and p-hydroxybenzoic acid (C7H6O3, Phba) was prepared in a H2O-C2H5OH mixed solution, and the crystal structure of [Pr2(H2L)2(Phba)4(H2O)2] · 2H2O (I) was determined by X-ray single crystal diffractometry. Complex I crystallizes in the monoclinic system, space group P21/c, a = 1.1050(4), b = 1.9534(7), c = 1.2376(4) ?, β = 94.955(7)°, and Z = 4. In the structure each Pr3+ ion lies in a single capped square antiprism geometry coordinated by carboxyl O and acyl O atoms and azomethine N atom of
one ligand (H2L− form), which coordinates via the keto form, four carboxyl O atoms from two Phba, and O atoms of two water molecules. In each
molecule, two tridentate ligands were coordinated by the H2L− form, and each Pr3+ ion was chelated by the carboxyl group from Phba. The carboxyl groups of H2L− and other two Phba were coordinated via μ2-bridging form and bidentate bridging form, respectively. Complex I and ligands Phba and H3L were also searched for biological activity against Valsa mali by the growth rate method. The result showed that the inhibitory
rate of ligands Phba and H3L is better than complex I, especially Phba. 相似文献
3.
Identification of peroxo groups in supramolecular layered structures as probed by Raman spectroscopy
T. A. Tripol’skaya I. V. Pokhabova P. V. Prikhodchenko G. P. Pilipenko E. A. Legurova N. A. Chumaevskii 《Russian Journal of Inorganic Chemistry》2009,54(3):464-466
Peroxide-containing supramolecular structures prepared by reacting lithium aluminum layered double hydroxides (Li-Al LDHs)
with concentrated hydrogen peroxide solutions were characterized by Raman spectroscopy. These compounds were formulated as
[LiAl2(OH)6](OH) · H2O2 · H2O(I) and [LiAl2(OH)6](OOH) · H2O2 · H2O(II). The frequencies 830 and 849 cm−1 in the spectra of compounds I and II were assigned to O—C stretching vibrations in two nonequivalent peroxo groups. The band
at 866 cm−1 in compound II was assigned to O—O vibrations in the hydroperoxo group (OOH)−. Proceeding from calculated strength factors, we inferred that the O—O bond in the hydroperoxo group of compound II is stronger
than in the H2O2 solvating group.
Original Russian Text ? T.A. Tripol’skaya, I.V. Pokhabova, P.V. Prikhodchenko, G.P. Pilipenko, E.A. Legurova, N.A. Chumaevskii,
2009, published in Zhurnal Neorganicheskoi Khimii, 2009, Vol. 54, No. 3, pp. 513–515. 相似文献
4.
The kinetics of the gas-phase reactions of the OH radical with (C2H5O)3PO and (CH3O)2P(S)Cl and of the reactions of NO3 radicals and O3 with (CH3O)2P(S)Cl have been studied at room temperature. Using a relative rate technique, the rate constants determined for the reactions of the OH radical with (C2H5O)3PO and (CH3O)2P(S)Cl at 296 ± 2 K and 740 torr total pressure of air were (5.53 ± 0.35) × 10?11 and (5.96 ± 0.38) × 10?11 cm3 molecule?1 s?1, respectively. Upper limits to the rate constants for the NO3 radical and O3 reactions with (CH3O)2P(S)Cl of <3 × 10?14 cm3 molecule?1 s?1 and <2 × 10?19 cm3 molecule?1 s?1, respectively, were obtained. These data are compared and discussed with previous literature data for organophosphorus compounds. 相似文献
5.
R. Atkinson J. Arey S. M. Aschmann E. C. Tuazon 《Research on Chemical Intermediates》1994,20(3-5):385-394
The formation yields of 1,2-epoxy-2-methyl-3-butene and 1,2-epoxy-3-methyl-3-butene have been measured from the reaction of O3 with isoprene at room temperature and one atmosphere total pressure of N2 and air diluents, with and without cyclohexane to scavenge the OH radicals formed in this reaction system. In addition, a relative rate method was used to determine a rate constant for the gas-phase reaction of O3 with 1,2-epoxy-2-methyl-3-butene of (2.5 ± 0.7) x 10-18 cm3 molecules-1 s-1 at 296 ± 2 K. Our data show that the epoxide yields in N2 and air diluents are the same, with formation yields of 1,2-epoxy-2-methyl-3-butene of 0.028 ± 0.007 and of 1,2-epoxy-3-methyl-3-butene of 0.011 ± 0.004. These data further show that the epoxides arise from the primary O3 reaction with isoprene, and not via the formation of O(3P) atoms from the O3 - isoprene reaction followed by reaction of these O(3P) atoms with isoprene. 相似文献
6.
During the etching of AZ 1350 photoresist in O2 and O2/CF4 discharges, ground-state concentrations of atoms (O, F, and H), and small radicals (OH, HO2, RO2) were measured in the discharge afterglow by EPR spectroscopy. In the case of CF4/O2 discharges, the dependence of O and F atom concentrations on the etch time reflects both surfäce oxidation and fluorination reactions in accordance with existing etch models. In the case of high-rate resist etching in pure O2 discharges, high concentrations of product radicals (H, OH and HO2) were detected and compared with resist free O2/H2O discharges. Kinetic modeling of the afterglow reactions reveals that the mean lifetime and, accordingly, the diffusion length of the etchant species O(3P) is drastically reduced in rapid reactions with OH and HO2. The results are used to simulate both etch homogeneity and the loading effect in a simple etch model. 相似文献
7.
V. L. Lobachev L. M. Dyatlenko G. P. Zimtseva 《Theoretical and Experimental Chemistry》2010,46(3):182-189
It was found that in a wide range of pH in the presence of boric acid the oxidation of diethyl sulfide (Et2S) with hydrogen peroxide in an i-PrOH–H2O medium occurs with the participation of H2O2, HOO–, monoperoxo-(B(OH)3OOH–), and diperoxoborates (B(OH)2(OOH)2−). The stability constants of peroxoborates and the rate constants for the reactions of H2O2, HOO−, B(OH)3(OOH)2−, and B(OH)2(OOH)2− with Et2S under these conditions were determined. 相似文献
8.
Summary Complexes of chromium(II) with diphenylphosphinate, Cr(O2PPh2)2 · H2O, diphenylphosphate Cr{O2P(OPh)2} · 1/2H2O, phenylphosphinate, Cr(O2PHPh)2 · 2H2O, phenyl-phosphonate, Cr(O3PPh) · H2O, and monofluorophosphate, Cr{O2P(OH)F}2 · H2O, are high-spin. From their reflectance spectra and antiferromagnetic behaviour the last three are believed to be three-dimensional polymers with R2PO
2
–
bridges in which some O atoms bridge two Cr atoms, leading to magnetic interaction. The other complexes show only weak magnetic interaction, and the reflectance spectra of Cr(O2PPh2)2 and its hydrate indicate that both contain planar CrO4 units. It is therefore believed to be a linear polymer with the Cr atoms well separated by double R2PO
2
–
bridges. The reflectance spectrum of Cr{O2P(OPh)2}2 suggests additional weak coordination of O atoms from adjacent polymer chains. 相似文献
9.
I. I. Seifullina L. Kh. Minacheva E. A. Chebanenko E. E. Martsinko V. S. Sergienko A. V. Churakov 《Russian Journal of Inorganic Chemistry》2011,56(12):1886-1893
Bis(citrato)hydroxogermanic(IV) acid was obtained for the first time in the complex [H5O2][Ge(H2Cit)(H2.5Cit)(OH)]2 · 2CH3COOH · 2H2O (H4Cit is citric acid). The complex was characterized by chemical analysis, X-ray powder diffraction, TGA, and IR spectroscopy.
Complex I was studied by X-ray crystallography. The crystals are triclinic; a = 10.0651(4) ?, b = 10.1918(4) ?, c = 10.5838(4) ?, α = 85.0110(10)°, β = 85.2170(10)°, γ = 86.7670(10)°, V = 1076.50(7) ?3, Z = 1, space group P[`1]P\bar 1, R1 = 0.0353 for 5709 reflections with I > 2σ(I). Complex I is composed of centrosymmetric dimeric complex anions [Ge2(H2Cit)2(H2.5Cit)2(OH)2]−, dioxonium cations [H5O2]+, and acetic acid and water molecules of crystallization. The coordination polyhedron of the Ge atom is a trigonal bipyramid.
Its equatorial plane comprises two O atoms of the deprotonated alcohol groups of two ligands H2Cit (A) and H2.5Cit (B) and the O atom of the terminal OH group (Ge-O, 1.7585–1.7754 ?; OeqGe(1)Oeq, 116.26°–127.64°). The axial positions are occupied by the carboxy O atom of the deprotonated carboxylate group of the α
branch of ligand A (α-Ge-O(C)(carb), 1.8882(12) ?)) and the carbonyl O atom of the hemiprotonated acetate α branch of ligand
B (α-Ge-O(C) 1.9615(12) ?, O(1)Ge(1)O(8) 170.47(5)°). In structure I, the complex dianion, the cation, and acetic acid and water molecules are united through hydrogen bonds into a three-dimensional
framework. 相似文献
10.
Crystals of novel heterepoly complexes (HPC) Na0.5Cs2 − x
[H0.5 − x
M
x
II
XIII(OH)6Mo6O18] · 7−8H2O (MII = Fe, Mn; XIII = Cr, Al) are synthesized. Crystal structures of the complexes Na0.5Cs2 − x
[H0.5 − x
FexCr(OH)6Mo6O18] · 7H2O (I) (x = 0.19) and Na0.5Cs2 − x
[H0.5 − x
MnxAl(OH)6Mo6O18] · 8H2O (II) (x = 0.22) are determined (space group Pbcn, Z = 8, a = 23.023(4) Å, b = 22.064(4) Å, c = 11.606(3) Å, V = 5895.66 Å3 for I and a = 22.972(9) Å, b = 22.002(8) Å, c = 11.543(5) Å, V = 5834.18 Å3 for II, respectively). The [XIII(OH)6Mo6O18]3− ligands were found to be coordinated in monodentate fashion to M atoms due to the participation of a terminal O atom of the
cis-MoO2 group in coordination with the Fe and Mn atoms, which was confirmed by IR data.
__________
Translated from Koordinatsionnaya Khimiya, Vol. 31, No. 9, 2005, pp. 663–676.
Original Russian Text Copyright ? 2005 by Gavrilova, Molchanov. 相似文献
11.
A quasi-classical trajectory (QCT) calculation with the fourth-order explicit symplectic algorithm for the N(4S) + O2(X3Σg−) → NO(X2Π) + O(3P) reaction has been performed by employing the ground and first-excited potential energy surfaces (PESs). Since the translational
temperature considered is up to 5000 K, the larger relative translational energy and the higher vibrational and rotational
level of O2 molecule have been taken into account. The affect of the relative translational energy, the vibrational and rotational level
of O2 molecule in the reaction cross-sections of the ground and first-excited PESs has been discussed in a extensive range. And
we exhibit the dependence of microscopic rate constants on the vibrational and rotational level of O2 molecule at T = 4000 K. The thermal rate constants at the translational temperature betweem 300 and 5000 K have been evaluated and the
corresponding Arrhenius curve has been fitted for reaction (1). It is found by comparison that the thermal rate constants
determined in this work have a better agreement with the experimental data and provide a more valid theoretical reference. 相似文献
12.
Xuean Chen Yinghua Zhao Jianlong Zuo Weiqiang Xiao 《Journal of solid state chemistry》2006,179(12):3911-3918
Two new hydrated borates, Zn8[(BO3)3O2(OH)3] and Pb[B5O8(OH)]·1.5H2O, have been prepared by hydrothermal reactions at 170 °C. Single-crystal X-ray structural analyses showed that Zn8[(BO3)3O2(OH)3] crystallizes in a non-centrosymmetric space group R32 with a=8.006(2) Å, c=17.751(2) Å, Z=3 and Pb[B5O8(OH)]·1.5H2O in a triclinic space group P1¯ with a=6.656(2) Å, b=6.714(2) Å, c=10.701(2) Å, α=99.07(2)°, β=93.67(2)°, γ=118.87(1)°, Z=2. Zn8[(BO3)3O2(OH)3] represents a new structure type in which Zn-centered tetrahedra are connected via common vertices leading to helical ribbons ∞1[Zn8O15(OH)3]17− that pack side by side and are further condensed through sharing oxygen atoms to form a three-dimensional ∞3[Zn8O11(OH)3]9− framework. The boron atoms are incorporated into the channels in the framework to complete the final structure. Pb[B5O8(OH)]·1.5H2O is a layered compound containing double ring [B5O8(OH)]2− building units that share exocyclic oxygen atoms to form a two-dimensional layer. Symmetry-center-related layers are stacked along the c-axis and held together by interlayer Pb2+ ions and water molecules via electrostatic and hydrogen bonding interactions. The IR spectra further confirmed the existence of both triangular BO3 and OH groups in Zn8[(BO3)3O2(OH)3], and BO3, BO4, OH groups as well as guest water molecules in Pb[B5O8(OH)]·1.5H2O. 相似文献
13.
The kinetics of hydroquinone-inhibited oxidation of acrylic acid and methyl methacrylate was studied volumetrically by measuring
the oxygen uptake in the presence of an initiator (azobisisobutyronitrile) at T = 333 K and P
O
2 = 1 and 0.21 atm. The oxidation of acrylic acid inhibited by 4-methoxyphenol was studied under the same conditions for comparison.
The rate constants of the reactions of the peroxyl radicals of acrylic acid (∼CH2CH(COOH)O2·) and methyl methacrylate (∼CH2CMe(COOMe)O2·) with hydroquinone (HOC6H4OH) (1.20 × 105 and 7.16 × 104 l mol−1 s−1, respectively) and of the reaction of peroxyl radicals of acrylic acid with 4-methoxyphenol (p-CH3OC6H4OH) (3.25 × 104 l mol−1 s−1) were measured. The stoichiometric inhibition factors f were determined. The reaction between the semiquinone radical and oxygen, O2 + HOC6H4O·, plays an important role, decreasing the factor f and the efficiency of the inhibition effect of hydroquinone. The rate constants of this reaction were calculated from kinetic
data: k = 5.72 × 102 (in acrylic acid) and 4.60 × 102 l mol−1 s−1 (in methyl methacrylate). 相似文献
14.
The relative enthalpies, ΔHo (0) and ΔHo (298.15), of stationary points (four minimum and three transition structures) on the •O3H potential energy surface were calculated with the aid of the G3MP2B3 as well as the CCSD(T)–CBS (W1U) procedures from which
we earlier found mean absolute deviations (MAD) of 3.9 kJ mol−1 and 2.3 kJ mol−1, respectively, between experimental and calculated standard enthalpies of the formation of a set of 32 free radicals. For
CCSD(T)-CBS (W1U) the well depth from O3 + H• to trans-•O3H, ΔHowell(298.15) = −339.1 kJ mol−1, as well as the reaction enthalpy of the overall reaction O3 + H•→O2 + •OH, ΔrHo(298.15) = −333.7 kJ mol−1, and the barrier of bond dissociation of trans-•O3H → O2 + •OH, ΔHo(298.15) = 22.3 kJ mol−1, affirm the stable short-lived intermediate •O3H. In addition, for radicals cis-•O3H and trans-•O3H, the thermodynamic functions heat capacity Cop(T), entropy So (T), and thermal energy content Ho(T) − Ho(0) are tabulated in the range of 100 − 3000 K. The much debated calculated standard enthalpy of the formation of the trans-•O3H resulted to be ΔfHo(298.15) = 31.1 kJ mol −1 and 32.9 kJ mol −1, at the G3MP2B3 and CCSD(T)-CBS (W1U) levels of theory, respectively. In addition, MR-ACPF-CBS calculations were applied
to consider possible multiconfiguration effects and yield ΔfHo(298.15) = 21.2 kJ mol −1. The discrepancy between calculated values and the experimental value of −4.2 ± 21 kJ mol−1 is still unresolved.
Note added in proof: Yu-Ran Luo and J. Alistair Kerr, based on the discussion in reference 12, recently presented an experimental
value of ΔfHo(298.15) = 29.7 ± 8.4 kJ mol−1 in the 85th edition of the CRC Handbook of Chemistry and Physics (in progress). 相似文献
15.
由摩尔比分别为1:2和1:8的NiCl2·6H2O和Na2B4O7·10H2O作为反应物, 合成两种非晶态镍硼酸盐, 同时通过水热法合成β-Ni(OH)2. 化学分析和热重-微商热重法(TG-DTG)分析结果确定两种非晶态镍硼酸盐的分子组成分别为NiO·0.8B2O3·4.5H2O和NiO·B2O3·3H2O. 激光拉曼(Raman)实验结果表明镍硼酸盐样品中主要存在的硼氧阴离子为B3O3(OH)52-和B2O(OH)62-. 同步辐射扩展X射线吸收精细结构(EXAFS)方法对样品进行结构解析, 通过数据拟合给出样品中Ni 原子周围近邻配位原子种类、配位数以及原子间距离. 用不同晶体结构作为标准对两种非晶态镍硼酸盐进行拟合的结果表明, 样品中Ni 原子周围局域结构与Ni3B2O6晶体(ICSD No.31387)中的吻合较好. Ni 原子周围配位原子为O、B和Ni, 对于NiO·0.8B2O3·4.5H2O, 配位数分别为5.7、3.8和3.8, 配位距离分别为0.208、0.263 和0.311 nm; 对于NiO·B2O3·3H2O, 配位数分别为6.0、4.0 和4.0, 配位距离分别为0.207、0.262和0.310 nm. 相似文献
16.
O. P. Charkin N. M. Klimenko D. O. Charkin S. H. Lin 《Russian Journal of Inorganic Chemistry》2007,52(8):1248-1261
The electronic and geometric structures and the energetic characteristics of a series of monomeric MC34H32N4O
4
0,+
and dimeric (MC34H32N4O4)
2
0,+
molecules, heme analogues and their positively charged ions with 3d-metal atoms M = Ti, V, Cr, and Mn, have been calculated by the density functional theory B3LYP method with the Gen−1 = 6−31G*(Fe) + 6−31G(C, H, N, O) and Gen−2 = 6−311+G*(Fe) + 6−31G*(C, H, N, O) basis sets. The computation results are compared with the analogous calculated data on the heme dimers (heme)
2
0,+
. Computations show that for the (MC34H32N4O4)
2
0,+
dimers, high-spin states are preferable. In these dimers, the rings are linked with each other by a pair of M-carbonyl bridges
M⋯Ob=C(OH) and a pair of hydrogen bridges OHb⋯N. The calculated energies of dissociation D of the dimers into monomers point to a rather high stability of the dimers at the beginning of the 3d series (D ∼ 2.3–3.6 eV for M = Ti, V), which decreases rapidly as the atomic number of M increases (D ∼ 0.5 eV for M = Cr and ∼0.4 eV for (heme)2). The positive ions (MC34H32N4O4)
2
+
are ∼0.8–1.0 eV are more stable to dissociation than their neutral congeners (MC34H32N4O4)2. The trends in the behavior of the energetic and structural characteristics of the dimers (distances R(M—N), displacements of M atoms from the porphyrin ring plane, parameters of the carbonyl and hydrogen bridges, character
of ring distortions, etc.), as well as in the spin density distribution between the metal atoms and the rings in the monomers
MC34H32N4O4 and dimers (MC34H32N4O4)2 caused by their ionization and going along the 3d series, are examined. In the mixed dimer (FeC34H32N4O4)(VC34H32N4O4), the rings are linked by only one strong carbonyl bridge V⋯Ob=C(OH), with some contribution made by the neighboring hydrogen bridge. The dissociation energy of this mixed dimer into monomers
is close to a half of the dissociation energy of the “symmetric” dimer (VC34H32N4O4)2.
Original Russian Text ? O.P. Charkin, N.M. Klimenko, D.O. Charkin, S.H. Lin, 2007, published in Zhurnal Neorganicheskoi Khimii,
2007, Vol. 52, No. 8, pp. 1332–1346. 相似文献
17.
Karim Adil Amor Ben Ali Minh Trung Dang Marc Leblanc 《Journal of fluorine chemistry》2007,128(4):404-412
The environment of H3O+, H2O, HF and F− species (non-bonded to metals) is considered in fluoride metalates which crystallise from the (Al(OH)3, Cr(OH)3, FeF3, ZrF4, Ta2O5)-tren-HFaq·-ethanol systems (microwave heating at 190 °C during 1 h). The presence of (H3O)(H2O)6+ clusters or H3O+ cations, of isolated or associated H2O molecules, of (HF2)− and F− anions is evidenced. The thermal stability of the solids depends strongly on the nature of the hydrogen-bonded species associated with the preceding cations or anions and on the formation of water ribbons or layers. 相似文献
18.
采用化学共沉淀方法从磷酸铁锂废料中提取FePO4·2H2O,并研究了回收过程中杂质形成的机理。在热力学计算基础上绘制了298和363 K时Fe-P-Li-H2O体系的电势(φ)-pH图,结果表明当pH≤5.0时,Fe(OH)3相可以自发地转成FePO4·2H2O相,从而得到高纯的FePO4·2H2O。但实验结果发现当溶液中铁、磷的物质的量之比(nFe∶nP)为1∶1,合成pH为1.5~2.2时得到的FePO4·2H2O中存在Fe(OH)3杂质,这是因为在共沉淀过程中少量Fe3+以Fe(OH)3快速沉淀,而陈化时Fe(OH)3相转化速率慢,因此FePO4·2H2O中含有Fe(OH)3 相似文献
19.
We have developed a technique for generating high concentrations of gaseous OH radicals in a reaction chamber. The technique, which involves the UV photolysis of O3 in the presence of water vapor, was used in combination with the relative rate method to obtain rate constants for reactions of OH radicals with selected species. A key improvement of the technique is that an O3/O2 (3%) gas mixture is continuously introduced into the reaction chamber, during the UV irradiation period. An important feature is that a high concentration of OH radicals [(0.53–1.2) × 1011 radicals cm?3] can be produced during the irradiation in continuous, steady‐state experiment. Using the new technique in conjunction with the relative rate method, we obtained the rate constant for the reaction of CHF3 (HFC‐23) with OH radicals, k1. We obtained k1(298 K) = (3.32 ± 0.20) × 10?16 and determined the temperature dependence of k1 to be (0.48 ± 0.13) × 10?12 exp[?(2180 ± 100)/T] cm3 molecule?1 s?1 at 253–328 K using CHF2CF3 (HFC‐125) and CHF2Cl (HCFC‐22) as reference compounds in CHF3–reference–H2O gas mixtures. The value of k1 obtained in this study is in agreement with previous measurements of k1. This result confirms that our technique for generating OH radicals is suitable for obtaining OH radical reaction rate constants of ~10?16 cm3 molecule?1 s?1, provided the rate constants do not depend on pressure. In addition, it also needed to examine whether the reactions of sample and reference compound with O3 interfere the measurement when selecting this technique. © 2003 Wiley Periodicals, Inc. Int J Chem Kinet 35: 317–325, 2003 相似文献
20.
Theoretical Studies on Mechanism and Rate Constant of Gas Phase Hydrolysis of Glyoxal Catalyzed by Sulfuric Acid
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Ming-qiang Huang Shun-you Caia Ying-min Liao Wei-xiong Zhao Chang-jin Hu Zhen-ya Wang Wei-jun Zhang 《化学物理学报(中文版)》2016,29(3):335-343
The gas phase hydration of glyoxal (HCOCHO) in the presence of sulfuric acid (H2SO4) were studied by the high-level quantum chemical calculations with M06-2X and CCSD(T) theoretical methods and the conventional transition state theory (CTST). The mechanism and rate constant of the ve di erent reaction paths are consid-ered corresponding to HCOCHO+H2O, HCOCHO+H2O H2O, HCOCHO H2O+H2O, HCOCHO+H2O H2SO4 and HCOCHO H2O+H2SO4. Results show that H2SO4 has a strong catalytic ability, which can signi cantly reduce the energy barrier for the hydration reaction of glyoxal. The energy barrier of hydrolysis of glyoxal in gas phase is lowered to 7.08 kcal/mol from 37.15 kcal/mol relative to pre-reactive complexes at the CCSD(T)/6-311++G(3df, 3pd)//M06-2X/6-311++G(3df, 3pd) level of theory. The rate constant of the H2SO4 catalyzed hydrolysis of glyoxal is 1.34×10-11cm3/(molecule s), about 1013 higher than that involving catalysis by an equal number of water molecules, and is greater than the reaction rate of glyoxal reaction with OH radicals of 1.10×10-11cm3/(molecule s) at the room temperature, indicating that the gas phase hydrolysis of glyoxal of H2SO4 catalyst is feasible and could compete with the reaction glyoxal+OH under certain atmospheric condi-tions. This study may provide useful information on understanding the mechanistic features of inorganic acid-catalyzed hydration of glyoxal for the formation of oligomer 相似文献