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利用求解含时薛定谔方程的方法, 研究了双原子N2分子在激光强度为1.5×1014 W·cm-2, 脉冲宽度为50 fs激光脉冲作用下的取向行为. 研究结果表明, 保持总激光强度不变, 将一束激光脉冲分成具有同样脉宽, 强度比为0.3636的两束激光脉冲, 当第一束脉冲产生的分子取向即将达到最大时, 加上有一定延迟时间的第二束脉冲能够使N2分子达到最大的取向程度. 相似文献
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烯丙醇类化合物是于天然产物和药物分子中的重要骨架[1-2].过渡金属催化的炔烃和酮类化合物的还原偶联反应是构建烯丙醇类化合物直接的方法之一[2].镍催化炔酮的还原偶联反应可以成功构建环状烯丙醇,并作为核心步骤多次应用于天然产物的合成之中[3-5]. 相似文献
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本文利用红外光谱、化学吸咐和激光表面反应技术,研究了丁烷在H-ZSM-5分子筛、SiO_2和γ-A1_2O_3表面上的激光表面反应规律;研究了不同激发模式、固体表面材料的红外特性及化学吸附能力、激光脉冲次数及脉冲间隔时间等因素对激光光能利用率的影响;证实了固体表面键激发模式的有效性,探讨了激光表面反应过程中能量吸收、积累、传递和损失的途径,提出了激光促进丁烷裂解的表面反应机理。 相似文献
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关于在强红外激光场作用下多原子分子在气相介质中的多光子吸收(MPA)和解离(MPD)巳经进行过大量的研究.但是,在固相介质中这方面的研究尚属少见.迄今为止,只有Ambartzumyan等报道的TEA-CO_2激光使冻结在隔离基体上(isolated-matrix)的SF_6分子发生选择性的光解反应,以及Karlov等用类似的方法对BCl_3分子的光解反应研究.最近我们研究了一系列固体甲酸铀酰化合物的红外光谱,发现其中UO_2~(2+)基团的反对称振动频率v_a均在912—952cm~(-1)范围,与TEA-CO_2激光支线频率相符.本文研究TEA-CO_2激光作用下,单结晶水甲酸铀酰和碱式甲酸铀酰化合物发生光解反应的共同特性,并根据实验结果,初步提出了该光解反应的可能机理,即在强红外激光场下,这些化合物可以吸收多个光子而达到具有较高能量的振动激发态,在具有还原性的甲酸根离子作用下发生光解反应. 相似文献
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全氟(3,4-二甲基-4-乙基己烯-[2])(1)虽早已合成,但有关它的反应至今报道不多。本文报道化合物1和烯丙醇在不同条件下的亲核取代反应和2-(1′-烯丙氧基四氟乙基)-全氟(3-甲基-3-乙基戊烯-[1])(2)的化学转化。1和烯丙醇的反应随溶剂和碱的变化而得到不同的产物。1和烯丙醇钠在FC-113中,于-40℃左右反应可得到2。若1与过量烯丙醇、三乙胺在35°~40℃反应40min,则得到2-烯丙氧基-全氟(3,4-二甲基-4-乙基已烯-[2])(3),但产率很低,绝大部分回收原料,并获得3-三氟甲基-3-五氟乙基-2,2-二氢五氟戊酸烯丙酯(5a)。若1与烯丙醇、碳酸钾在丙酮中于50~60℃反应,则主要产物为4和5a。以上化合物的结构均经~1HNMR,~(19)FNMR,IR和元素分析等证明。 相似文献
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采用原位显微Raman光谱和18O同位素示踪技术,以325 nm激光为激发光源,对立方Nd2O3上过氧物种的光诱导生成过程进行了详细表征,进一步证实过氧源于分子氧对晶格氧的氧化反应. 结果还表明,325 nm激光在室温下即可诱导过氧的生成,在实验条件下,生成的过氧物种可与Nd2O3的晶格氧发生快速的氧交换反应,位于Nd2O3体相的晶格氧也可迁移至样品表层进而参与过氧的生成. 325 nm激光照射有助于促进晶格氧的迁移以及晶格氧与分子氧之间的氧交换反应. 相似文献
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The thermodynamics and mechanism of the reaction of elemental mercury with ozone has been studied computationally. The effect of water and water dimer molecules on the reaction has also been investigated. For dry reaction, we obtained two pathways and geometry optimization, atoms in molecules analysis and vibrational frequencies of all component of reaction have been used for confirming of reaction mechanism. Thermodynamic variable of reaction has been calculated. For the reaction in the presence of the water, our studies focus on ozone‐mercury complex reaction with water and water dimer and obtained the mechanism of reactions. Comparison of wet and dry reaction shows the energy profile of reaction decreases with water molecule correspond to experimental prediction. Calculated thermodynamic variable of all reaction shows the Gibbs free energy of reaction decreases with the number of water molecule. 相似文献
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The reaction path of the reaction HCN + OH→ CN + H2O was traced with Fukui's theory of intrinsic reaction coordinate by using ab initio MO method (at UMP4/6-31G** level) with gradient technique. On this basis, the dynamics properties along the reaction path was investigated by reaction path Hamiltonian theory. The rate constants of this reaction at different temperatures were calculated by conventional and variational transition state theory with tunneling correction. The theoretically calculated rate constants are in good agreement with experimental results, this shows that the title reaction is an one step, direct reaction. 相似文献
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Thies Thiemann Yasuko Tanaka Keiko Ideta Shuntaro Mataka 《Central European Journal of Chemistry》2006,4(3):403-427
The Wittig reaction of carbaldehydes with alkoxycarbonylhalomethylidenetriphenylphosphoranes can be performed with ease in
solventless systems. The analogous reaction of carbaldehydes with acylhalomethylidenetriphenylphosphoranes requires a small
amount of solvent, such as chloroform, in order for the reaction to proceed. The products of the reaction are versatile precursors
for further transformations, such as the Suzuki-Miyaura cross-coupling reaction. 相似文献
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The kinetics of reaction of bromo-epoxy resin with oleic acid in the presence of dimethylbenzylamine catalyst was studied. The reaction is a zero order reaction with respect to oleic acid, first order with respect to epoxy group and 0. 74 order with respect to dimethylbenzylamine. The reaction rate constants at various temperatures and activation energy were determined. The mechanism of this reaction was discussed. Keywords Tetrabromobisphenol-A, Bromo-epoxy resin, Oleic acid kinetics, Reaction mechanism 相似文献
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用密度泛函理论(DFT)方法在B3LYP/6-31G*水平上研究了苯甲醛肟与炔丙醇加成反应的微观机制和热力学、动力学行为. 结果表明, 在苯甲醛肟与炔丙醇加成反应过程中, 8个可能反应通道的过渡态中均形成非平面五元环结构, 其中苯甲醛肟的Z、E构型特征得到了部分保留, 但主要部分的键长、键角均发生了变化, 电荷也进行了重新分布. 苯甲醛肟以羟基型参与反应的4个反应通道均为吸热反应和热力学非自发过程, 它们均具有较高的反应势垒、较慢的反应速率和较小的平衡常数; 而以离子型参与反应的四个反应通道均为放热反应和热力学自发过程, 它们的反应势垒较低, 反应速度较快, 平衡常数也较大, 故苯甲醛肟应主要以离子型参与反应. 炔丙醇的两种取向对应着加成反应的两种产物, 反应达到平衡后, 3-羟甲基二氢异噁唑为主要产物. 相似文献
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Tietze LF Kettschau G Heuschert U Nordmann G 《Chemistry (Weinheim an der Bergstrasse, Germany)》2001,7(2):368-373
The twofold Heck reaction of the vinylpyrroles 3a and 3b with the iodobenzenes 4a-c led to the linear pyrrole oligomers 5, 6, and 7. The synthesis of both symmetrical and unsymmetrical oligomers, such as 10a and 10b, was also accomplished by a Heck reaction of 8 and 9 and by a Heck reaction of 3a and 11 followed by a Wittig reaction and a second Heck reaction with 8. The pentacyclic oligomers 14 and 19 were prepared by a twofold Heck reaction of 13 with 4 and by a twofold Heck reaction of 15 with 16 followed by a Wittig reaction and a twofold Heck reaction with 8. 相似文献
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Tsuchiya T Okada Y Shimizu T Hirabayashi K Kamigata N 《The Journal of organic chemistry》2008,73(1):76-80
Unsaturated thiacrown ethers with 15, 18, and 21 members were oxidized to sulfoxides by the reaction with m-CPBA. The reaction with t-BuOCl at -20 degrees C also afforded sulfoxides, whereas the reaction at room temperature yielded cis-trans isomerized compounds. The cis-trans isomerized compound was also obtained by the photochemical reaction or by the reaction with NCS and NCP. Meanwhile, the reaction with NBS and NBP provided an acetal via 1,2-bridged bromonium intermediate. 相似文献
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Ozone has been reacted with phenol in thin supported layers, and the dynamics of this reaction has been investigated. The stoichiometry of this reaction coincides with the stoichiometry of the same reaction in solution. Specific reaction rate (β) has been determined for various phenol conversions. The effective rate constant of the reaction, estimated by extrapolating β to zero reaction time, is significantly higher than the rate constant of the reaction in solution. The reaction between ozone and phenol is diffusion-controlled. The reaction products form a barrier layer, which protects the deeper phenol layers against ozone. The barrier layer is as thick as 8–15 phenol monolayers. 相似文献