异构体

The results also show that subtituent position on the benzene ring has a great influence on the transfer volume. The trends of change of δ〓ΔΦ〓〓 for mand p-isometers with the composition of the mixed solvent are similar. However, the position and amplitude of the limit valve are different from each other. These are discussed according to the inductive effect and the resonance effect.

研究发现：取代基在苯环上的取代位置对迁移偏摩尔体积有明显影响，间、对位取代的异构体在DMF-水混合溶剂中的δ〓Δφ〓〓随混合溶剂的组成变化规律相似，但极值点的位置及幅度有所不同，根据诱导效应和共轭效应对此进行了讨论。

The trigonal prism yields three isomers also, but there are only two octahedral arrangements for this formulation.

三棱柱也有三个异构体，而对于这个分子式，仅有两种八面体排布。

Base-catalysed hydrolysis is a typical course involving deprotonation leaving of Cl- and formation of the trigonal bipyramidal intermediate; edge displacement and ligand folding courses involve leaving of Cl- and formation of the square pyramidal intermediates.

典型的途径有经式异构体的碱催化水解，过程通过脱氢、脱氯以及三角双锥中间过渡态或中间体的形成来完成；另一途径为边沿取代及配体翻转历程，过程通过脱氯及四角锥的形成来完成。

ABSTRACT In this paper, by employing dicarboxylic acids with special conformation, i.

利用几个结构上有特点的二元羧酸，即2，6-吡啶二甲酸、三个异构体苯二甲酸，顺丁烯二酸和4，4'-联苯甲酸作为首要桥基配体，并结合使用含氮中性配。。。

All of the possible 21 isomers for C_77N~+, an isoelectronic molecule of C_78, were investigated by the INDO methods based on C_78(C_2V).

用INDO系列方法对C78(C2V)的等电子体C77N+的所有21种可能异构体进行系统的理论研究。

Through the use of high-level quantum-chemical calculations, two experimentally observed isoenergetic isomers are assigned to complexes in which a water dimer is hydrogen-bonded either to the carbonyl oxygen of the ester function or to the amino nitrogen.

通过高层次的量子化学计算上的应用，两个实验观察isoenergetic异构体被分配到复合物，其中一个水二聚体的氢键要么酯的羰基氧的功能或对氨基氮。

For the first time, enantiomers of C2-symmetric 1,1 -spirobiindane-7,7'-diol were resolved with crude menthyl chloroformate by phase-transfer catalysis in the presence of tetrabutylammonium bromide. The reaction was carried out at 0℃-rt. The diastereomers of SPINOL bis-menthyl carbonate can be separated by simple crystallization using alcohol. The hydrolysis of the diastereomers was carried out via aqueous NaOH/EtOH solution.

首次通过相转移催化的方法对螺双二氢茚二酚进行了有效的拆分，用L--氯甲酸薄荷醇酯做拆分剂，以四丁基溴化铵为催化剂在0℃-室温下进行酯化反应生成非对映体衍生物，以乙醇作溶剂，通过重结晶的方法分离衍生物，在水-乙醇混合溶剂条件下，用强碱NaOH或KOH分别水解，制得相应的光学纯度大于99%ee的两个异构体SPINOL，其中总收率：--SPINOL，78.2%；--SPINOL，80.6%。

The effect of silicon atom in substrate on the reaction rate and the stereoselectivity of enzymatic reactions was revealed by comparison of horse liver alcohol dehydrogenase-catalyzed stereoselective dehydrogenation of the three isomers of acetyltrimethyl propanone and their carbon analogues in aqueous/organic biphasic systems.

本项目通过对比在水－有机溶剂两相系统中，马肝醇脱氢酶催化三甲基硅烷丙酮的三个异构体及其碳类似物的光学选择性脱氢反应，揭示了底物中的硅原子对酶反应速度、立体选择性的影响规律，成功地合成了高对映体纯度的手性有机硅醇，并实现了辅酶的再生。

Resolution of racemic drugs by lipase catalysis offers an excellent technology for the preparation of single-isomer chiral drugs in organic solvent.

在有机相中，脂肪酶催化消旋体的拆分，为制备单异构体手性药物提供了重要的技术手段。

Different from the primary pyrolysis procedure of pyrrole with the complex tautomers the initial precursors of the major pyrolysis products are simple and the corresponding pathways are more distinct.

与吡咯热解初期的形成的复杂异构体不同的是，吡啶热解的主要产物前驱体相对单一，热解产物为母体脱氢的吡啶自由基、母体脱氢开环链状自由基和母体直接开环的产物。

With Death guitarist Schuldiner adopting vocal duties, the band made a major impact on the scene.

随着死亡的吉他手Schuldiner接受主唱的职务，乐队在现实中树立了重要的影响。

But he could still end up breakfasting on Swiss-government issue muesli because all six are accused of nicking around 45 million pounds they should have paid to FIFA.

不过他最后仍有可能沦为瑞士政府&议事餐桌&上的一道早餐，因为这所有六个人都被指控把本应支付给国际足联的大约4500万英镑骗了个精光。