北柴胡挥发油的成份研究I.

The chemical constituents of essential oil from the roots of Bupleurum chinense DC. were examined by means of GC-MS technique combined with preparative GC TLC and IR. As a result of the analyses, twenty components were identified namely: pentanoic acid, caproic acid, heptanoic acid, 2-heptenoci acid, caprylic acid, 2-octenoic acid, pelargonic acid, 2-nonenoic acid, phenol, cresol, ethylphenol, thymol, eugenol, 0-methoxyphenol, γ-heptalactone, γ-octalactone, γ-decalactone, γ-undecalactone, messoialactone and vanillin acetate.     

稠环芳烃系列化合物化学位移的计算 IV.^1H化学位移加合性规律的量子力学基础

Based on a starting point of the McWeeny Huckel-London perturbation theory approximation, a formula similar to the fourmula of additivity rule for the calculations of the chemical shifts of condensed aromatic hydrocarbons has been derived. The quantum mechanical basis of additivity rule is thus indicated by this formula. It is shown that by using the concept of aromatic shift and sigma ratio, this method for calculation of proton chemical shifts has the virtues of definite physical meaning and simple calculation. It can also be extended to the calculation of the proton chemical shifts of substituents fr the molecules of this series.     

化学镀镍诱发过程的研究 II.用电子能谱研究诱发过程

In the previous paper, it was reported that a sudden decrease down to -0.6V and lower in stationary potential was observed from the stationary potential-time curve and the reaction of electroless nickeling could be induced by metallic iron catalyst when it was in contact with substrate metallic copper. In this paper, AES and XPS surface analysis and depth profile technique was employed to investigate the surface and depth distribution of Ni, Cu, Fe and P in the nickel coating deposited on the substrate metal. The experimental results showed that there was a thin adsorption layer consisting of C, S and Cl. The pure electroless nickel deposition, its Ni/P ratio being about two, existed under the adsorption layer. A layer with rapidly changed Ni/P ratio occurred close to the surface of substrate metal, under this layer the substrate metal was alloyed with Ni and P, thus becoming Cu-Ni-P alloy. The ratio of components in this alloy was found to be Cu:Ni:P=56:36:5. This fact explained why the electroless nickel deposition can preferably adhered to the substrate metal. In inducing process, Fe was not detected by AES from the substrate metal and nickel deposition. Thus it showed that the inducing reaction takes place without the deposition of inducing metal.     

中药白头翁的皂素III.配基结构的研究

The structure of anemosapogenin 1 has been proved to be 3β, 23-dihydroxylup-20 (29)-en-28-oic acid on the basis of spectroscopic (IR, ^1H NMR, C-13 NMR, MS) evidences and chemical transformations, namely, the formation of acetonide 3 from 6, the acid catalysed rearrangement of 1 and 2 into 18 (α)-oleanan-28, 19β-olide derivatives 4 and 5 respectively and finally, the conversion of 7 through LiAiH4 reduction into the known compound, lup-20(29)-ene- 3β, 23, 28-triol. The third sugar component of the saponin is shown to be arabinose.     

化学修饰电极的研究 V:铁卟啉修饰电极对氧的催化还原

By surface organio synthesis a Fe (III) tetra-o-aminophenyl porphyrin modified electrode was successfully prepared on glassy carbon electrode surface through amidization. The preparation considitions were invesigated in detail. Using cyclie voltametry and cyclie semidifferential polarography in an acidic aqueous solution the behavior of the catalytic reduction of oxygen on iron porphyrin modified electrode was studied. Based on experimental results it was shown that the irreversible process of 2- electronreduction to hydrogen peroxide belongs to EC parallel catalytic process.     

次级化学平衡反相高效液相色谱法分离银杏酚酸

采用LC/(-)ESI-MS法对银杏叶中的致敏性成分银杏酚酸进行了鉴定。利用次级化学平衡理论,建立了银杏酚酸的反相银化高效液相色谱分离方法。从色谱热力学角度对银离子分离银杏酚酸的影响进行了考察。在流动相中添加银离子,降低了具不饱和侧链银杏酚酸的保留时间,且银离子浓度与容量因子的对数之间存在良好线性关系。在确定的色谱条件下,四种银杏酚酸均获得较高的分离度,表明反相银化液相色谱是分离碳数与饱和度不相同的银杏酚酸同系物的有效方法。     

(BN)n团簇的结构和稳定性

用HF方法、密度泛函理论的B3LYP以及微扰理论的MP2方法，在6—31G(d)基组 水平上，对(BN)n(n=1-16)团簇的各种可能结构进行了优化．讨论了环状与笼状稳 定团簇的几何构型、自然键轨道(NBO）、振动频率、结合能、核独立化学位移 (NICS)和能量二次差分，得到了(BN)n(n＝1-16)团簇结构的稳定性信息．比较了 HF，B3LYP以及MP2三种理论方法对(BN)n团簇的适应性所表现出的差异．     

核磁共振化学位移的MNDO/GIAO微扰法计算

本文首次应用MNDO近似和规范不变的原子轨道(GIAO)计算了化学位移,提出了MNDO/GIAO微扰计算法及单电子算符1/r_m,L_m及L_m/r_m~3的简单有效积分法.通过优化选择MNDO的β_μ参数,对一组典型有机分子~(13)C化学位移的计算结果表明,理论值与实验数据符合得很好,并克服了SOS微扰法对坐标原点的依赖性.     

Fe2S2(SH)4[2-,3-]的从头计算

正确的能级次序应与分子的活性位置一致.实验证实,铁硫蛋白或模型化合物Fe_2S_2(SR)~(2-)及Fe_4S_4(SR)_4~(2-)的活性位置在端基,易于发生多种取代反应,而Fe_2S_2和Fe_4S_4实一般是稳定的.但是,经过电化学还原生成的Fe_2S_2(SR)_4~(3-),却不可逆地二聚化,生成Fe_4S_4(SR)_4~(2-)