Theoretical Study of the Scattering Resonance State, Reaction Mechanism and Partial Potential Energy Surface of the F＋CH4→HF ＋CH3 Reaction

Many reactions with fluorine atoms have the important applications in the areas of theatmosphere and the chemical lasers, such as the reaction of fluorine atoms with methane. F( 2 P) CH 4 (X1A1)→HF(X1 Σ ) CH 3 (X 2 A′′2) ?H0300k=-32.3 kcal mol ?1 It…     

Quasi-Classical Trajectory Study of the Chemical Reaction Ca+CH3I

The Ca＋CH3I→CaI＋CH3 reaction system has been studied with the quasi-classical trajectory method on the extended Lond-Eyring-Polanyi-Sato（LEPS） potential energy surface. At collision energy Ecol=10.78 kJ/mol, the calculated results show that the CaI vibrational population peaks are located at v=2. The calculated cross section decreases slowly with the collision energy increasing. The angle product distributions tend toward backward scattering. The calculated （P2（J^1·K）） values deviate slightly from-0.5 and decrease with increasing collision energy. The Quasiclassical trajectory calculation（QCT） results are in reasonable agreement with experimental data. Moreover, the dynamics of the reaction has been discussed.     

Theoretical Study on the Reaction Mechanism of F2 ＋ 2HBr = 2HF ＋ Br2

1 INTRODUCTION The replacement reactions between halide and hy- drogen halide, or halide and halide are basic reac- tions in chemistry. Goldfinger et al. have speculated by experiment that the gas reaction between chlorine and hydrogen bromide might be a two-step intermo- lecular reaction[1, 2]. But gas reactions between other halides and hydrogen halides haven’t been reported experimentally so far. About theoretical investiga- tion, colinearity quantum mechanics, vibrational tran- sitio…     

Theoretical Studies of the Reaction Mechanisms of CH3S＋NO2

The potential energy surface for the CH3S NO2 reaction has been studied using the ab initio G3(MP2) method. A variety of possible complexes and saddle points along the minimum energy reaction paths have been characterized at UMP2 (full)/6-31G(d) level. The calculations reveal dominating reaction mechanisms of the title reaction: CH3S NO2 firstly produce intermediate CH3SONO,then break up into CH3SO NO. The results are valuable to understand the atmospheric sulfur compounds oxidation mechanism.     

Quasi-classical Trajectory Study of the Intramolecular Isotope Effect in the Reaction O（3p）＋H2/HD

Theoretical studies of the dynamics of the reactions O（3p）＋H2/HD（ν=0, j=0）→OH＋H have been performed with quasi-classical trajectory method （QCT） on an ab initio potential surface for the lowest triplet electronic state of H2O（aA＂）. The QCT-calculated integral cross sections are in good agreement with the earlier time-dependent quantum mechanics results. The state-resolved rotational distributions reveal that the product OH rotational distributions for O＋HD have a preference for populating highly internally excited states compared with the O＋H2 reaction. Distributions of differential cross sections show that directions of scattering are strongly dependent on the choice of quantum state. The polarization dependent generalized differential cross-sections and the distributions were calculated and a pronounced isotopic effect is revealed. The calculated results indicate that the product polarization is very sensitive to the mass factor.     

A Study of the Reaction Dynamics for the H+BrCH_3 System Using Quasi-classical Trajectory Theory

In the present paper, scattering probabilities and rate constants of different channels for the H + BrCH_3 reaction system have been calculated by means of quasiclassical trajectory (QCT) method. Several important kinetic effects such as vibrational enhancement, channel competition, vibrational adiabaticity, mass combination, coupling of angular momenta and the relation between the kinetic effects and the feature of the potential energy surface have been discussed. Based on these analyses, a direct-type rebonded mechanism for this reaction has been inferred and used to explain the nonsymmetric angular distribution of the products crossed-molecular beam experiment. The agreement of calculation with experimental results is satisfactory.     

Density Functional Study on the Reaction Mechanism for the Reaction of Ni^＋ with Ethane

The mechanism of the reaction of Ni^ (^2D) with ethane in the gas-phase was studied by using density functional theory.Both the B3LYP and BLYP functionals with standard all-electron basis sets are used to give the detailed information of the potential energy surface (PES) of [Ni,C2,H6]^ . The mechanisms forming the products CH4 and H2 in the reaction of Ni^ with ethane are proposed.The reductive eliminations of CH4 and H2 are typical addition-elimination reactions.Each of the two reactions consists of two elementary steps:C-C or C-H bond activations to form inserted species followed by isomerizations to from product-like intermediate.The rate determining steps for the elimination reactions of forming CH4 and H2 are the isomerization of the inserted species rather than C-C or C-H bond activations .The elimination reaction of forming H2 was found to be thermodynamically favored compared to that of CH4.     

金属碳笼化学反应的理论研究（Ⅰ）——Ti8C12^＋＋CH3I→Ti…

用量子化学从头计算方法对反应Ｔｉ８Ｃ１２＾＋＋ＣＨ３Ｉ→Ｔｉ８Ｃ１２＾＋－Ｉ＋ＣＨ３·进行了理论研究，对Ｔｉ８Ｃ１２＾＋只能与一个卤素原子结合的实验事实给予了合理的理论解释。     

Ab initio Mechanism Study on the Reaction of Chlorine Atom with Formic Acid

The potential energy surface(PES) for the reaction of Cl atom with HCOOH is predicted using ab initio molecular orbital calculation methods at UQCIDS(T,full)6-311 G(3df,2p)//UMP2(full)/6-311 G(d,P) level of theory with zero-point vibrational energy (ZPVE) correction.The calculated results show that the reaction mechanism of Cl atom with formic acid is a C-site hydrogen abstraction reaction from cis-HOC(H)O molecule by Cl atom with a 3.73kJ/mol reaction barrier height,leading to the formation of cis-HOCO radical which will reacts with Cl atom or other molecules in such a reaction system.Because the reaction barrier height of O-site hydrogen abstraction reaction from cis-HOC(H)O molecule by Cl atom which leads to the formation of HCO2 radical is 67.95kJ/mol,it is a secondary reaction channel in experiment,This is in good agreement with the prediction based on the previous experiments.     

Syntheses and Characterizations of （CH3CH2CH2CH2NH3）6（BiI6）（I）2I3 and （NH3CH2CH2NH3）2Bi2I10

The title compounds have been respectively synthesized by solution process and solvothermal reaction, and their crystal structures were determined by X-ray diffraction method. For （CH3CH2CH2CH2NH3）6（BiI6）（I）2I3 1, it crystallizes in tficlinic, space group P1^- with Mr = 2049.76, a = 8.5719（1）, b = 11.7461（3）, c = 15.700（1）A, V = 1451.4（1）A^3, Z = 1, Dc = 2.345 g/cm^3, F（000） = 924, μ（MoKα） = 8.907 mm^-1, T = 293（2） K, the final R = 0.0655 and wR = 0.0804 for 2399 observed reflections with I 〉 2σ（I）. For （NH3CH2CH2NH3）2Bi2I10 2, it crystallizes in monoclinic, space group P21/n with Mr= 1811.20, a = 8.434（4）, b = 13.862（6）, c = 13.362（6）A, V = 1499.9（12）A^3, Z = 2, Dc = 4.010 g/cm^3, F（000） = 1536,μ（MoKα） = 22.007 mm^-1, T = 293（2） K, the final R = 0.0584 and wR = 0.1451 for 1798 observed reflections with I 〉 2σ（I）. The structures of 1 and 2 contain halobismuthate monomer and dimers, respectively. It is noteworthy that the dimers and their organic counters in 2 connect each other by N…I hydrogen bonds to form a layered structure, and the electrostatic interactions and crystal packing forces between layers give rise to the packing of the crystal. The optical absorption spectra of 1 and 2 reveal the appearance of sharp optical gaps of 2.13 and 2.01 eV, respectively.     

Quantum Chemical Study on a New Mechanism of One-carbon Unit Transfer Reaction： The Water-assisted Mechanism

It is a theoretical study on the water-assisted mechanism of one-carbon unit transfer reaction, in which the energy barrier for each transition state lowered by about 80-100 kJ/mol when compared with the one in no-water-involved mechanism. The water-assisted path 4 is the favorite reaction way. Our results well explained the presumption from experiments.     

A Study on the Kinetics of the Catalytic Reforming Reaction of CH4 with CO2： Determination of the Reaction Order

The kinetics of the catalytic reforming reaction of methane with carbon dioxide to produce synthesis gas on a Ni/(α-A1203 and a HSD-2 type commercial catalyst has been studied. The results indicate that the reaction orders are one and zero for methane and carbon dioxide, respectively, when the carbon dioxide partial pressure was about 12.5-30.0 kPa and the temperature was at 1123-1173 K. However, when the carbon dioxide partial pressure was changed to 30.0-45.0 kPa under the same temperature range of 1123-1173 K, the reaction orders of methane and carbon dioxide are one. Furthermore, average rate constants at different temperatures were determined.     

Quantum Chemical Study on the Reaction Mechanism of OBrO Radical with OH Radical

The reaction mechanism of OBrO with OH has been studied using the B3LYP/6-311 G(d,p) and the high-level electron-correlation CCSD(T)/6-311 G(d,p) at single-point. The results show that the title reaction could probably proceed by four possible schemes, generating HOBr O2, HBr O3, BrO HO2 and HOBrO2 products, respectively. The main channel is the one to yield HOBr O2. The whole reaction involves the formation of three-membered, four-membered and five-membered rings, followed by the complicated processes of association,H-shift, Br-shift and dissociation. All routes are exothermic.     

Study on the Mechanism of the Rearrangement Reaction of 3-n-Butylphthalide by Deuterium-Labelling

InthePangetal.report[l],l-methyl-5-cchp'tetrahdronaPhthalenewasobtalnedfromthetreatInentof3-ntwlphthalideusingAlCl3ascatalStinCS2byaproposedl,4-hydridetransfrprocess.InordertoexPlorethemechasticdetallsofthereaction,wepreParedastableisotope-labelledcomPound--I',l'ch-dotero-3-n-butylphthalideasfollowstl,lall-deutero-ldiutanolwasobtalnedbyreduedonreachonofethy1butwatewithNaBD4andAJCl3indiglpoeI2],treatmentoftheproductwithphosphoroustribroITildetogive1,1-dideutero-lbromobutane,whichunderwe…     

同位素示踪研究K2CO3/CH3I促进的碳酸二甲酯直接合成反应

 采用同位素示踪技术,系统地研究了K2CO3/CH3I促进的CO2插入甲醇直接合成碳酸二甲酯(DMC)的反应机理. 结果表明,固体碱碳酸钾催化剂直接参与了DMC的合成过程, DMC分子中的羰基由CO2插入甲醇后形成,两个甲基分别来源于甲醇和碘甲烷. 本文将以往文献中提出的DMC生成机理和二甲醚生成机理结合起来,并对其进行适当补充后,可以很好地解释实验结果.     

Scattering Resonance States and Partial Potential Energy Surface of Reaction I ＋ HI （ v = 0 ） → IH （ v＇ = 0 ） ＋ I

The partial potential energy surface of the I ＋ HI →IH ＋ I reaction involving the translational and vibrational motions has been constructed at the QCISD（ T ）//MP4SDQ level with the pseudo potential method that is helpful to interpreting the scattering resonance states. The lifetimes of the scattering resonance states in the title reaction obtained from the partial potential energy surface are about 90-120 fs, which agrees with the result of high-resolved threshold photodetachment spectroscopy of anion IHI^- measured by Neumark.     

Theoretical Study on the Mechanism of VO2^＋ ＋ H2 Reaction in the Gas Phase

The mechanism of VO2+ + H2 reaction in the gas phase was investigated by using density functional theory (DFT) at the CCSD//B3LYP/6-311G(2d, p) level. According to our calculation results, the different reaction mechanisms were found for the singlet and triplet potential energy surfaces (PESs). Especially, the crossing points (CPs) among different PESs were located by means of the intrinsic reaction coordinate (IRC) approach presented by Yoshizawa et al., and the structures and energies of the corresponding minimum energy crossing points (MECPs) were obtained by the mathematical algorithm proposed by Harvey et al. Finally, the frontier molecular orbital (FMO) interaction analyses about MECP1 and MECP2 were used to prove our calculation results.     

^3A＇ and ^3A＂ Energy Surfaces for the VS^＋ ＋ CO2→VO^＋ ＋ COS Reaction

The title reaction proceeds via a one- and two-step mechanism along the ^3A＂ and ^3A＇ surfaces, respectively. The ^3A＇ excited state surface has a lower barrier than the ^3A＂ ground state surface （11.6 and 16.0 kca1/mol, respectively）, We suggest that, at low energies, the reaction proceeds along the A＇ surface and then makes an intersystem crossing to the A＂ surface and yields the ground state product VO^＋（^3∑^-）, which may explain the small VO^＋ cross-section at low energies observed in the experiment     

High Resolution Crossed Beams Scattering Study of the F＋HD→DF＋H Reaction

Crossed beams scattering study was carried out on the F＋HD→DF＋H reaction using high- resolution H-atom Rydberg tagging time-of-flight technique. Vibrational state-resolved differential cross sections were measured, with partial rotational state resolution, at eight collision energies in the range of 2.51-5.60 kJ/mol. Experimental results indicated that the product angular distributions are predominantly backward scattered. As the collision energy increases, the backward scattered peak becomes broader gradually. Dependence of product vibration branching ratios on the collision energy was also determined. The experimental results show that the DF products are highly inverted in the vibrational state distribution and the DF （v＇=3） product is the most populated state. Furthermore, the DF （v＇=l） product has also been observed at collision energy above 3.97 kJ/mol.     

Ten-Dimensional Quantum Dynamics Study of H+CH3D→H2+CH2D Reaction

The mode selectivity of the H+CH3D→H2+CH2D reaction was studied using a recently developed ten-dimensional time-dependent wave packet method.The reac-tion dynam...