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1.
用密度泛函理论(DFT)的B3LYP方法,在6-311G、6-311+G( d)、6-311++G( d, p) 基组水平上研究了CH 3CF 2O 2与HO 2自由基反应机理. 结果表明, CH3CF 2O 2与HO 2自由基反应存在两条可行的通道. 通道CH3CF 2O 2+HO 2→IM1→TS1→CH 3CF 2OOH+O 2的活化能为77.21 kJ•mol -1,活化能较低,为主要反应通道,其产物是O 2和CH 3CF 2OOH. 这与实验结果是一致的;而通道CH 3CF 2O 2+HO 2→IM2→TS2→IM3→TS3→IM4+IM5→IM4+TS4→IM4+OH+O 2→TS5+OH+O 2→CH 3+CF 2O+OH+O 2→CH 3OH+CF 2O+O 2的控制步骤活化能为93.42 kJ•mol -1,其产物是CH 3OH、CF 2O和O 2. 结果表明这条通道也能发生,这与前人的实验结果一致. 相似文献
2.
New ester salts [R 3NH] +[F 5SC(SO 2F)C(O)OR′] − where RH, CH 3CH 2 and R′CH 3,(CH 3) 2CH have been prepared from corresponding esters and amines. The sodiumsalt Na[F 5SC(SO 2F)C(O)OCH(CH 3) 2] was used to prepare the following -substitutedderivatives: SF 5CX(SO 2F)C(O)OCH(CH 3) 2, XBr, Cl. The crystal structure of[(C 2H 5) 3NH] +[F 5SC(SO 2F)C(O)OCH 3] − was determined and is monoclinic: P2 1/ n; a=8.758(2) Å, b=9.645(2) Å and c=19.167(4) Å; β=97.92(3)°; V=1603.6 Å 3; Z=4. 相似文献
3.
Six new cluster derivatives [Rh 2Co 2(CO) 6(μ-CO) 4(μ 4,η 2-HCCR)] (R=FeCp 2 1, CH 2OH 2, (CH 3O)C 10H 6CH(CH 3)COOCH 2CCH 3) and [RhCo 3(CO) 6(μ-CO) 4(μ 4,η 2-HCCR)] (R=FeCp 2 4, CH 2OH 5, (CH 3O)C 10H 6CH(CH 3)COOCH 2CCH 6) were obtained by the reactions of [Rh 2Co 2(CO) 12] and [RhCo 3(CO) 12] with substituted 1-alkyne ligands HCCR [R=FeCp 2 7, CH 2OH 8, (CH 3O)C 10H 6CH(CH 3) COOCH 2CCH 9] in n-hexane at room temperature, respectively. Alkynes insert into the Co---Co bond of the tetranuclear clusters to give butterfly clusters. [Rh 2Co 2(CO) 6(μ-CO) 4(μ 4,η 2-HCCFeCp 2)] (1) was characterized by a single-crystal X-ray diffraction analysis. Reactions of 1, 2 with 7, 8 and ambient pressure of carbon monoxide at 25 °C gave two known cluster complexes [Co 2(CO) 6(μ 2, η 2-HCCR)] (R=FeCp 2 10, CH 2OH 11), respectively. All clusters were characterized by element analysis, IR and 1H-NMR spectroscopy. 相似文献
4.
由混合二烃基二氯化锡与水杨醛缩苯胺类Schiff碱反应,合成了24种新的有机锡配合物。经元素分析、NMR、TG-DSC测定和X射线粉末衍射分析,确定有14种是有机锡与Schiff碱的1:1配合物,10种是1:2配合物。配体是以酚羟基氧原子与锡原子配位,摩尔电导率测定表明这些配合物均为非电解质。 相似文献
5.
Electronic chemiluminescence from the reaction of selected ground state ( 2S 1/2) or metastable ( 2D 5/2, 2D 3/2) copper atoms with fluorine has been studied using a hollow cathode-flowing afterglow reactor. The observed signal related to the Cu( 2S) and Cu*( 2D) atom densities, indicate that the chemiluminescence cross-section for Cu*( 2D) atoms is about 10 4 times larger than for Cu( 2S) atoms. This strong propensity is explained in terms of a direct reaction, initiated by a harpooning process, during which the Cu + ion core of the reactant (3d 10 for Cu( 2S) and 3d 94s for Cu*( 2D)) is conserved in the products (ionic structure Cu +(3d 10)F − for the CuF ground state and Cu +(3d 94s)F − for the CuF*(a, A, B, C, D) chemiluminescent states). 相似文献
6.
Mechanisms of RN 3 (R=CH 3, CH 3CH 2, (CH 3) 2CH, (CH 3) 3C) dissociations are proposed based on CAS, MP2 and B3LYP methods. The energy gaps between the ground-state reactants RN 3 and the intersystem crossing (ISC) points are only a little lower than respective potential energy barriers of the spin-allowed reactions, 1RN 3 → 1RN + 1N 2. The ISC point, therefore, is considered as a transition state of the spin-forbidden reactions, 1RN 3 → 3RN + 1N 2. The methods of IRC and topological analysis of electron density are used to explain and predict the thermal dissociation pathways of the reactions studied. 相似文献
7.
Gaussian-2 ab initio calculations were performed to examine the six modes of unimolecular dissociation of cis-CH 3CHSH + (1 +), trans-CH 3CHSH + (2 +), and CH 3SCH 2+ (3 +): 1 +→CH 3++ trans-HCSH (1); 1 +→CH 3+ trans-HCSH + (2); 1 +→CH 4+HCS + (3); 1 +→H 2+ c-CH 2CHS + (4); 2 +→H 2+CH 3CS + (5); and 3 +→H 2+ c-CH 2CHS + (6). Reactions (1) and (2) have endothermicities of 584 and 496 kJ mol −1, respectively. Loss of CH 4 from 1 + (reaction (3)) proceeds through proton transfer from the S atom to the methyl group, followed by cleavage of the C–C bond. The reaction pathway has an energy barrier of 292 kJ mol −1 and a transition state with a wide spectrum of nonclassical structures. Reaction (4) has a critical energy of 296 kJ mol −1 and it also proceeds through the same proton transfer step as reaction (3), followed by elimination of H 2. Formation of CH 3CS + from 2 + (reaction (5)) by loss of H 2 proceeds through protonation of the methine (C H) group, followed by dissociation of the H 2 moiety. Its energy barrier is 276 kJ mol −1. On both the MP2/6-31G* and QCISD/6-31G* potential-energy surfaces, the H 2 1,1-elimination from 3 + (reaction (6)) proceeds via a nonclassical intermediate resembling c-CH 3SCH 2+ and has a critical energy of 269 kJ mol −1. 相似文献
8.
Oxidative addition of ethyl iodide to PdMe 2(2,2′-bipyridyl) in (CD 3) 2CO gives the unstable “PdIMe 2Et(bpy)”, which undergoes reductive elimination to form PdIR(bpy) (R = Me, Et), ethane, and propane. Ethene and palladium metal are also formed, and are attributed to decomposition of PdIEt(bpy) via β-elimination. Similar results are obtained with n-propyl iodide, although a palladium(IV) intermediate was not detected, but CH 2=CHCH 2X (X = Br, I) and PhCH=CHCH 2Br give isolable complexes fac-PdXMe 2(CH 2CH=CHR)(L 2) (R = H, Ph; L 2 = bpy, phen). The propenyl complexes decompose at ambient temperature to form ethane, a trace of PdXMe(L 2), and mixtures of [Pd(η 3-C 3H 5)(L 2)]X and [Pd(η 3-C 3H 5)(L 2)]-[Pd(η 3-C 3H 5)X 2]; for fac-PdBrMe 2(CH 2CH=CH 2)(bpy) the major palladium(II) product is [Pd(η 3-C 3H 5)(bpy)]Br. 相似文献
9.
在G3MP2B3结构优化和能量计算的基础上, 采用RRKM理论和疏松过渡态模型重新估算了过氧硝酸乙酰酯(PAN)的热分解反应PAN→CH 3C(O)OO+NO 2(R1)的反应速率常数, 得到与实验值吻合的结果.用同样的模型计算了PAN→CH 3C(O)O+NO 3(R2)的反应速率常数. 结果表明, 在相同的反应条件下, R1是主要的分解通道, R2是次要通道, R2的反应速率常数比R1的小两个数量级. 相似文献
10.
The complex triplet potential energy surface of the C 2H 3N system is investigated at the UB3LYP and CCSD(T) (single-point) levels in order to explore the possible reaction mechanism of C 2H 3 radical with N( 4S). Eleven minimum isomers and 18 transition states are located. Possible energetically allowed reaction pathways leading to various low-lying dissociation products are obtained. Starting from the energy-rich reactant C 2H 3+N( 4S), the first step is the attack of the N atom on the C atom having one H atom attached in C 2H 3 radical and form the intermediate C 2H 3N(1). The associated intermediate 1 can lead to product P 1 CH 2CN+H and P 2 3CH 2+ 3HCN by the cleavage of C–H bond and C–C bond, respectively. The most favorable pathway for the C 2H 3+N( 4S) reaction is the channel leading to P 1, which is preferred to that of P 2 due to the comparative lower energy barrier. The formation of P 3 3C 2H 2+ 3NH through hydrogen-abstraction mechanism is also feasible, especially at high temperature. The other pathways are less competitive comparatively. 相似文献
11.
A series of novel arylantimony(V) triphenylgermanylpropionates with the formula (Ph 3GeCHR 1CHR 2CO 2) nSbAr (5−n) (R 1=H, Ph; R 2=H, CH 3; n=1, 2) were synthesized and characterized by elemental analysis, IR, 1H-NMR, 13C-NMR and mass spectroscopy. The crystal structures of Ph 3GeCH(Ph)CH 2CO 2SbPh 4 and [Ph 3GeCH 2CH(CH 3)CO 2] 2Sb(4-ClC 6H 4) 3 were determined by X-ray diffraction. The in vitro antitumor activities of some selected compounds against five cancer cells are reported. 相似文献
12.
The hydroboration of allyl sulfonamides (4-H 3CC 6H 4SO 2NRCH 2CH=CH 2: R=H, 1; Ph, 2; Bz, 3) with catecholborane (HBcat) using different rhodium catalysts has been examined using multinuclear NMR spectroscopy. Reactions give complex product distributions, regardless of the choice of catalyst, arising from a competing isomerization reaction. This isomerization reaction can be used with N-substituted allyl sulfonamides 2 and 3 to give the corresponding enamines (4-H 3CC 6H 4SO 2CH=CH 2CH 3), which in turn react with HBcat to give regioselective formation of one isomer (4-H 3CC 6H 4SO 2NRCH 2CH 2(Bcat)CH 3). 相似文献
13.
本文用自由基捕捉剂2,3,4,6-四甲基亚硝基苯(ND)及苯亚甲基叔丁基氮氧化合物(PBN)与ESR相结合的方法研究了CnH 2n+1OH(n=1,2,…8)、(CH 3) 2CH(CH 2) nOH(n=0,1,2)、CH 2=CHCH 2OH及C 6H 5CH 2OH等十三种醇与二苯甲酮的光化夺氢反应中的活泼自由基,结果表明: 1.用ND时,二苯酮分别夺取CnH 2n+1OH、(CH 3) 2CH(CH 2) nOH及RCH 2OH(R=CH 2=CH、C 6H 5)中α-C、叔-C及α-C上的氢,而捕捉到C n-1H 2n-1CHOH、(CH 3) 2CH(CH 2) nOH及RCHOH自由基。 2.用PBN时,捕捉的自由基与ND捕获的相同。 相似文献
14.
The title complex [NH_3CH_2CH(NH_2)CH_3]_2 [M(Ⅵ)O_2(OC_6H_4O)_2](M= Mo_(0.6)W_(0.4))was synthesized via a simple solution-phase chemical route.The determination of single crystal X-ray diffraction revealed that the title compound is crystallized in a monoclinic system with P2(1)/n space group,a=1.0913(10)nm,b=1.0442(10)nm,c=1.8842(19)nm,α=90°,β=96.530(17)°,γ=90°,Z=4,and V=2.133(4)nm3.The mononuclear anionic unit [M(Ⅵ)O2(OC6H4O)2]2-displays chiral pseudo-octahedral [MO_6] coordination geometry and is linked by chiral cations via hydrogen bond and π…π stacking interaction.The transmission electron microscopy images show that the title complex is comprised of nano-particles with diameters ranging from 20 to 50 nm.The NMR study shows the 1H downfield chemical shifts of [NH_3CHaHbCH(NH_2)CH_3] cations in the title complex when it is mixed with adenosine-triphosphate(ATP),and the chemical shift difference between Ha and Hb is increased greatly,and most of the catecholate ligands dissociate from the central metal atoms.The DNA cleavage activity experiment reveals that DNA cleavage promoted by the title complex is lower than that by Na_2MoO_4 which possesses antitumor pro-perty,but higher than that by Na_2WO_4. 相似文献
15.
The reactions of hydroxyl radical, hydrogen atom and hydrated electron intermediates of water radiolysis with N-isopropylacrylamide (NIPAAm) were studied by pulse radiolysis in dilute aqueous solutions. OH, H and e aq− react with NIPAAm with rate coefficient of (6.9±1.2)×10 9, (6.6±1)×10 9, and (1.0±0.2)×10 10 mol −1 dm 3 s −1. In OH and H radical addition to the double bond mainly -carboxyalkyl type radicals form, (OHCH 2CH √C(N- i-C 3H 7)O and CH 3CH √C(N- i-C 3H 7)O). In reaction of e aq− oxygen atom centered radical anion is produced (CH 2CHC √(N- i-C 3H 7)O −), the anion undergoes reversible protonation with p Ka=8.7. There is also an irreversible protonation on the β-carbon atom that produces the same radical as forms in H atom reaction (CH 3CH √C(N- i-C 3H 7)O). The -carboxyalkyl type radicals at low NIPAAm concentration (0.1–1 mmol dm −3) mainly disappear in self-termination reactions, 2 kt,m=8.4×10 8 mol −1 dm 3 s −1. At higher concentrations the decay curves reflect the competition of the self-termination and radical addition to monomer (propagation). The termination rate coefficient of oligomer radicals containing a few monomer units is 2 kt≈2×10 8 mol −1 dm 3 s 1. 相似文献
16.
A detailed ab initio study based on the CASSCF and CASPT2 methods has been carried out on the 3 2A ′ potential energy surface (PES) involved in the reaction between N( 2D) and O 2 to produce O( 3P) and NO. All the stationary points have been characterised and a grid of more than 800 points has been fitted to an analytical function. This PES has been used to obtain the rate constant of this reaction at different levels of theory (statistical and quasiclassical trajectory methods, taking into account recent data of our own on other PESs involved in the reaction) and has been compared with the experimental results obtaining a good agreement. 相似文献
17.
Absolute kinetic energy distributions and yields associated with ground state 3P and excited state 1D oxygen atoms have been obtained for O − anion electron stimulated desorption from condensed O 2 in the electron energy range 6–15 eV. The observed yields are understood as resulting essentially from dissociative electron attachment reactions via the two lowest 2Σ +g O −2 resonance states through adiabatic and non-adiabatic transitions to the limits O −( 2P) + O( 3P) and O −( 2P) + O( 1D). The kinetic energy distributions show the prominent role of electron multiple collision processes and post-dissociation interactions of the O − anions in the condensed phase. 相似文献
18.
The Ca( 1D 2, 3P J) + CH 3 → CaI(A,B) + CH 3 reactions system has been studied by measuring its chemiluminescence under beam-gas conditions. Absolute values of the state-to-state reaction cross-sections were determined at low collision energy
. In addition, the electronic branching ratio and product energy disposal have been determined for each metastable reaction. The major changed observed in the chemiluminescence when comparing the Ca( 1D 2) reaction versus that of Ca( 3P J) is the total yield associated with the former reaction. To the best of our spectral resolution neither the electronic branching ratio e.g. CaI(A)/CaI(B) nor the internal CaI energy disposal change significantly as the metastable Ca( 1D 2)/Ca( 3P J) ratio is varied. In spite of the fact that the Ca( 3P J) reaction is less exoergic, the CaI product appears with a higher fraction of internal energy than that of Ca( 1D 2) reaction. Thus, the fraction of the total energy appearing in CaI internal energy amounts to 57.5% in the Ca( 3P J) reaction while it is 19.3% only for the Ca( 1D 2) reaction. This difference is discussed in the light of a distinct mechanism associated with the attack of the excited Ca atom into the C---I bond. No significant chemiluminescence yield was found for the energetically open CaCH *3 channels. The product chemiluminescence polarization was also measured as a function of the metastable concentration. A significant degree of polarization was found depending upon the specific electronic excitation. The analysis of the polarization emission associated to the parallel CaI(X 2Σ+ ← B 2Σ+) emission led into a strong polarization of the product rotational angular momentum. The comparison of the product rotational alignment for the kinematically identical Ca(1D2, 3PJ, 1P1) + CH3 → CaI* (B2Σ+) + CH3 reaction system showed that the CaI rotational polarization diminishes in the 3PJ → 1D2 → 1P1 sequence, e.g. as the reaction exothermicity increases. In addition the degree of polarization associated with other emission bands as for example CaI(X 2Σ+ ← A 2Π1/2) indicates the presence of a parallel transition which was been interpreted as mixing of Hund's case (a) and (c) appropriate for this heavy CaI diatom produced with a high rotational excitation. 相似文献
19.
1-Buten-3-yl-n-butyldichlorotin, generated in situ by redistribution of ( E/ Z)-2-butenyltri-n-butyltin and BuSnCl 3, reacts readily with neat RCHO (R = CH 3, C 2H 5, (CH 3) 2CH) at 25°C to give linear alcohols RCH(OH)CH 2CH---CHCH 3 and/or 2,3,4,6-tetrasubstituted tetrahydropyrans, CH 2CH(R)OCH(R)CH(CH 3)CH-(Cl), which are mainly in the cis-configuration with respect to the CH(CH 3)-CH(Cl) bond. When R = (CH 3) 3C and C 6H 5, only the homoallylic alcohols are obtained. These cis-stereoconvergent syntheses are explained in terms of kinetic control of the formation of adducts obtained by insertion of one or two aldehyde molecules into the organotin substrate. 相似文献
20.
CpCo(CO) 2 is oxidised by [Cp 2Fe]BF 4 (Cp = C 5H 5) in the presence of neutral ligands L to give the dications [CpCoL 3] 2+ (L = SMe 2, S(n-C 4H 9) 2, PMe 3, C 5H 5N, MeCN; Me = CH 3). In [CpCo(SMe 2) 3] 2+, sulfane ligands are substituted by neutral ligands L, L---L and L---L---L, to give the complexes [CpCoL 3] 2+ (L = SeMe 2, TeMe 2, PMe 3, P(OMe) 3, AsMe 3, SbMe 3, t-C 4H 9NC, C 5H 5N, MeCN), [Cp-Co(L---L)SMe 2] 2+ (L---L = R 2P(CH 2) nPR 2, n = 1, 2, R = C 6H 5; bipyridine, o-phenanthroline, neocuproin) and [CpCo(L---L---L)] 2+ (L---L---L = RP(CH 2CH 2PR 2) 2, R = C 6H 5). The dications react with iodide resulting in the monocations [CpCoL 2I] + and [CpCo(L---L)I] +. Azacobaltocinium cations [CpCo(C 4R 2H 2N)] + (R = H, CH 3) are obtained by reaction of [CpCo(SMe 2) 3] 2+ with metal pyrrolides. 相似文献
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