共查询到20条相似文献,搜索用时 62 毫秒
1.
2.
3.
4.
采用荧光光谱研究了N-丁基-2-乙氧基硫代吖啶酮的光化学反应机理.结果表明:在Xe灯光照下,N-丁基-2-乙氧基硫代吖啶酮转变成了相应的吖啶酮,用紫外-可见光谱和质谱证实了吖啶酮的存在;生成的吖啶酮可被二苯基碘NFDA1 盐猝灭,它们之间的荧光猝灭遵循电子转移的反应机理.实验又证明了由硫代吖啶酮、二苯基碘NFDA1 盐和硫代水杨酸三者组成的光聚合引发体系的引发效果最好. 相似文献
5.
6.
合成了一系列的10-苄基吖啶酮类化合物, 并探讨了一种用硼氢化钠氢化还原吖啶酮制备10-苄基-9,10-二氢吖啶的简便方法. 吖啶酮1与氯化苄及其衍生物2在氢化钠/N,N-二甲基甲酰胺/碘化钾中反应高产率生成10-苄基吖啶酮类化合物3; 3经硼氢化钠氢化还原生成10-苄基-9,10-二氢吖啶类化合物4, 产率88%~96%. 反应中没有得到预期的产物10-苄基-9,10-二氢吖啶醇类化合物4’, 其反应机理可能是3首先被硼氢化钠还原成醇中间体4’, 4’在硼氢化钠存在下不稳定, 迅速地被进一步还原成4. 相似文献
7.
8.
以5-芳基-1,3-环基环己二酮为原料合成了8个未见报道的吖啶酮衍生物,其结构均经元素分析,IR和^1H NMR光谱确证。其中3-呋喃基-6,7-亚甲二氧基-9-甲基-1(2H,4H)-吖啶醇对一些肿瘤细胞有抑制作用。 相似文献
9.
10.
11.
12.
George C. Schatz Jay K. Badenhoop Charles W. Eaker 《International journal of quantum chemistry》1987,31(1):57-63
A quasiclassical trajectory surface hopping method has been used to study H(v) + H2 → H + H for v = 0, 3, 7, 10, 13, and 17 with an emphasis on determining the H internal energy and angular momentum distributions for high v. For v = 13 and 17, significant cross sections are found for producing H at energies above its dissociation energy. An average metastable H lifetime of 11.5 ps for v = 13 and 4.7 ps for v = 17 is found, but there is also a much longer lived component to the lifetime distributions that is more important for v = 13 than for v = 17. Some of the longer lived metastables correspond to high angular momentum orbiting states of H, but other sources of metastability are also present. 相似文献
13.
14.
Andrzej Leś 《Theoretical chemistry accounts》1985,66(6):375-393
Intermolecular potential energy curves for the hydrogen bonded systems H2O·H2S, H2O·H2Se and H2S·H2S were calculated with nonempirical pseudopotentials using optimized-in-molecules basis sets augmented by polarization functions. The H2O·H2O interaction energy curve has been also considered as a test case. The present results for H2O·H2S and H2S·H2S indicate much weaker intermolecular interactions than those found in previous ab initio calculations. The H2O·H2Se interaction was found to be quite similar to H2O·H2S.This work was partly supported by the Polish Academy of Sciences within the Project PAN-09, 7.1.1.1On leave from Quantum Chemistry Laboratory, Dept. of Chemistry, University of Warsaw, Pasteura 1, 02-093. Warsaw, Poland 相似文献
15.
《International journal of mass spectrometry and ion processes》1998,172(1-2):1-14
The reactions of H2O+, H3O+, D2O+, and D3O+ with neutral H2O and D2O were studied by tandem mass spectrometry. The H2O+ and D2O+ ion reactions exhibited multiple channels, including charge transfer, proton transfer (or hydrogen atom abstraction), and isotopic exchange. The H3O+ and D3O+ ion reactions exhibited only isotope exchange. The variation in the abundances of all ions involved in the reactions was measured over a neutral pressure range from 0 to 2 × 10−5 Torr. A reaction scheme was chosen, which consisted of a sequence of charge transfer, proton transfer, and isotopic exchange reactions. Exact solutions to two groups of simultaneous differential equations were determined; one group started with the reaction of ionized water, and the other group started with the reactions of protonated water. A nonlinear least-squares regression technique was used to determine the rate coefficients of the individual reactions in the schemes from the ion abundance data. Branching ratios and relative rate coefficients were also determined in this manner.A delta chi-squared analysis of the results of the model fitted to the experimental data indicated that the kinetic information about the primary isotopic exchange processes is statistically the most significant. The errors in the derived values of the kinetic information of subsequent channels increased rapidly. Data from previously published selected ion flow tube (SIFT) study were analyzed in the same manner. Rigorous statistical analysis showed that the statistical isotope scrambling model was unable to explain either the SIFT or the tandem mass spectrometry data. This study shows that statistical analysis can be utilized to assess the validity of possible models in explaining experimentally observed kinetic behaviors. 相似文献
16.
R. Hippler O. Plotzke W. Harbich H. Madeheim H. Kleinpoppen H. O. Lutz 《Zeitschrift für Physik D Atoms, Molecules and Clusters》1991,18(1):61-67
The coherent excitation of H(n=2) in H+, H - He collisions was investigated at incident energies of 5–25 keV. From a polarization analysis of the emitted Lyman-α radiation as a function of an external electric field, the partial cross sections for excitation to the H(2s) and the H(2p m) magnetic substates and the real part of thes ?p 0-coherence were extracted. For H+-He collisions, the measured partial cross sections are in fair agreement with previous two-electron calculations by Kimura and Lin; the agreement with one-electron calculations of Jain et al. is, particularly at the lower incident energies, less satisfactory. For both collision systems, an energy-dependent forward-backward asymmetry corresponding to a shift of the center-of-charge relative to the center-of-mass (dipole moment) was observed. In H+ - He collisions, the measured dipole moment was positive; it thus corresponds to an electron trailing behind the proton. The same analysis applied to the H - He system showed the electron riding in front of the proton. 相似文献
17.
Marcin Buchowiecki 《International journal of quantum chemistry》2012,112(4):1107-1113
Rate constant ratios k(T)/k(1,500K) for two symmetrical reactions H? + H2 → H2 + H? and H+ + H2 → H2 + H+ are reported. Direct method based on quantum instanton approximation for evaluation of the temperature dependence of the quantum‐mechanical reaction rate constant is used. Implementation of the theory involves thermodynamic integration and path integral Monte Carlo method. Results of anionic case shows resemblance to neutral case, whereas cationic case is significantly different and below 1,000K rate constant shows strong deviation form linearity of Arrhenius plot due to high activation barrier. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2012 相似文献
18.
E. Gianinetti G. F. Majorino E. Rusconi M. Simonetta 《International journal of quantum chemistry》1969,3(1):45-56
The configuration interaction method has been applied to the H2 and H3 systems. The effect of increasing the size of the atomic Slater-type orbital basis has been studied. A minimization procedure with respect to orbital exponents has been carried out. 相似文献
19.
《Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy》1988,44(9):883-887
Electronic excitation in H2O, H2S, H2Se and H2Te molecules has been studied by the EELS technique. Spectra of H2S and H2Se are remarkably similar with the 1b1-nd transition most intense. The intensity of the first transition 1b1-nsa1 decreases through H2O to H2Se and this transition is absent in H2Te. Transitions observed by EELS have been compared with optical absorption studies. A correlation diagram of the occupied and the excited states has been provided for these four molecules by making use of UVPES and EELS. 相似文献
20.
The effect of the torsional and stretching vibrations of C2H6 on the H + C2H6 --> H2 + C2H5 reaction
We present a three-dimensional quantum scattering model to treat reactions of the type H + C2H6 --> H2 + C2H5. The model allows the torsional and the stretching degrees of freedom to be treated explicitly. Zero-point energies of the remaining modes are taken into account in electronic structure calculations. An analytical potential-energy surface was developed from a minimal number of ab initio geometry evaluations using the CCSD(T,full)/cc-pVTZ//MP2(full)/cc-pVTZ level of theory. The reaction is endothermic by 1.5 kcal mol(-1) and exhibits a vibrationally adiabatic barrier of 12.0 kcal mol(-1). The results show that the torsional mode influences reactivity when coupled with the vibrational C-H stretching mode. We also found that ethyl radical products are formed internally excited in the torsional mode. 相似文献