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961.
1,2,4-三嗪类化合物具有抗癌、抗病毒、杀虫、抑制中枢神经系统等多种作用。前文用苯甲酰基硫代甲酰胺直接与氨基脲反应,制备了8种新的4,6-二取代-3-酮-5-硫酮-1,2,4-三嗪类化合物(a—h),本文测定了其电子轰击质谱、高分辨质谱及联动扫描质谱,以了解其质谱裂解途径。  相似文献   
962.
用停止-流动分光光度法研究了Eu~(2+)与二甲酚橙(XO)间快速电子转移反应的动力学规律。求得了速控步骤的动力学参数。如反应级数(n=2)、几个不同温度下的速率常数(k_(278 K)=5.7×10~8 L·mol~-·s~(-1), k_(s38 K)=1.01×10~9 L·mol~(-1)·s~(-1))、活化能(E=7.6×10~3 J·mol~(-1)), 以及指前因子(A=1.5×10~(10) L·mol~(-1)·s~(-1)), 并判断出其为溶液中扩散控制型反应。根据实验现象与测试结果, 提出了Eu~(2+)与XO的反应分别在Eu~(2+)相对过量和在XO过量时的反应机理, 并判断了各反应步骤速率常数之间的相对关系。  相似文献   
963.
A new quantum scattering approach (linear combination of arrangement channels-scattering wavefunction, LCAC-SW) proposed by Deng and his co-workers is used to calculate collinear state-to-state reaction probabilities for the F + H2(v) → HF(v') + H system. Several interesting problems such M threshold energy, compound states and enhance by translational energy of the reactants and the vibration excitation of products are discussed and they are compared with other theoretical investigations reported in the literature. It is shown that the LCAC-SW approach is the successful one of quantum scattering methods.  相似文献   
964.
N-取代吩噻嗪和DDQ的电荷转移络合作用   总被引:1,自引:0,他引:1  
具有盼嘤酸化学结构的化合物有广泛的用途I‘-\其中吩嘤埃衍生物在医学上用作抗精神病药物特别受到药理学家们的注意,发现其药理作用与其分子提供电子的能力有关卜‘」但是我们应该注意到,作为抗精神病药物的吩嚷嚷衍生物,其吩座爆分子的氮原子都连有一个叔胺基链问,例如氯丙障(I)和奋乃静(11).而我们知道,胺类特别是叔胺类有强的提供电子的能力*;在上述的药物分子中是主要的提供电子因素,因此以这类化合物作为给体研究其供电子能力,是不能实际反映吩嘤嗓分子本身的给电子能力的.吩嘤噪类属于二苯并杂环化合物,分子中既…  相似文献   
965.
5-Amino-4-cyano-8-isobutyl-7-isopropyl-6-thiocarbamoyl-2-azabicyclo[2.2.2]oct-5-en-3-thione was synthesized by the condensation of isovaleryl aldehyde with cyanothioacetamide. The structure of the product was established by X-ray crystallography.  相似文献   
966.
The interaction of labeled dinitrogen complexescis-(Me2PhP)4Mo(15N2)2 andtrans-(dppe)2W(15N2)2 with non-labeled nitronium and nitrosonium fluoroborates,14NO2BF4 and14NOBF4, in sulfolane at room temperature in the presence of H2SO4 results in rapid formation of labeled nitrous and nitric oxides (15N14NO,15NO), as well as15N14N. The yield of the products depends on the reagent ratio and reaches 10–20 mol. % per mole of a complex under optimum conditions. The mechanism of the reactions found is proposed. It involves the step of protonation of the dinitrogen ligand to form the corresponding hydrazido(2–) derivatives, which are then attacked by nitronium or nitrosonium cations. In accordance with the mechanism proposed, it was established that the hydrazido(2–) complexes, (Me2PhP)3Mo(15N2H2)Cl2 and (dppe)2W(15N2H2)Cl2, are capable of forming15N14NO,15NO, and15N14N under the action of14NO2BF4 and14NOBF4 in the absence of an acid.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 13–13, July, 1995.  相似文献   
967.
In this work, we used the hydrothermal method to synthesize Eu3+ ion-doped cubic BaF2 nanorods, which is a luminescent material. The clubbed structures were well crystallized and exhibited face-centred cubic structures, as indicated by powder X-ray diffraction, scanning electron microscopy, electron diffraction, and transmission electron microscopy. The luminescent properties were studied, and local symmetry surrounding Eu3+ ions and electronic transition processes included. The results indicated that Eu3+ occupied only one C4ν site in nanorods.  相似文献   
968.
N-2-Thiazolylacrylamide (NTA) was polymerized by a radical route to obtain the polymer in good yield. The polymer with a pendent heterocyclic group is soluble in common organic solvents, which allow to prepare the corresponding metal complexes with higher loads easily. FTIR, ^1H NMR, elemental analysis, and energy-dispersive X-Ray spectroscopy (EDX) were applied to characterize these materials. The magnetic behavior of Fe(Ⅱ) and Nd(Ⅲ) complexes of poly(N-2-thiazolylacrylamide) was examined by a PPMS-9T magnetometer, exhibiting the characteristics of a soft ferromagnet. It is found that the Nd(Ⅲ) complex has an extremely high relative saturation magnetization of 35 emu/g.  相似文献   
969.
Amao Y  Komori T 《Talanta》2005,66(4):976-981
An optical CO2 sensor based on the overlay of the CO2 induced absorbance change of pH indicator dye α-naphtholphthalein in poly(isobutyl methacrylate) (polyIBM) layer with the fluorescence of tetraphenylporphyrin (TPP) in polystyrene layer is developed. The observed luminescence intensity from TPP at 655 nm increased with increasing the CO2 concentration. The ratio I100/I0 value of the sensing film consisting of α-naphtholphthalein in polyIBM and TPP in polystyrene layer, where I0 and I100 represent the detected luminescence intensities from a layer exposed to argon and CO2 saturated conditions, respectively, that the sensitivity of the sensor, is estimated to be 192. The response and recovery times of the sensing film are less than 6.0 s for switching from argon to CO2, and for switching from CO2 to argon. The signal changes are fully reversible and no hysterisis is observed during the measurements. The highly sensitive optical CO2 sensor based on fluorescence intensity changes of TPP due to the absorption change of α-naphtholphthalein in polyIBM layer with CO2 is achieved.  相似文献   
970.
The conformations and heats of formation of all trans(T)- and cis(C)-2- and 3-methyl-substituted T- and Cbicyclo[4.4.0]decanes (BD) were calculated by the MM2 method of molecular mechanics. It was shown that the conformationally mobile T-2-Me-CBD and T-3-Me-CBD can exist in normal conditions as an inseparable mixture of conformers with a different equatorial or axial orientation of the Me groups. The Raman scattering (RS) spectra of TBD and CBD were investigated. RS bands whose frequencies were sensitive to the type of ring linkage and orientation (but not the position) of the Me substituents were detected in the 700–300 cm–1 region.A. V. Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences, 117912 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 9, pp. 2089–2097, September, 1992.  相似文献   
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