查询词典 tautomerism

The calculated results indicate that there are two absolutely opposite regions in the vicinity of 5-FU. In one of the regions, water molecules can assist the tautomerism from 5-FU to its enol form 5-FU(superscript *, whereas in another region, water molecules can protect 5-FU from tautomerizing to 5-FU(superscript *).

研究发现，在5-氟尿嘧啶周围存在两类不同的区域，在其中一类区域中，水分子能促进质子转移的发生；而在另一类区域中，水分子却能阻碍质子转移的发生。

The influence of solvent and medium on the absorption spectrum and the equilibrium between azo tautomerism and hydrazone tautomerism was discussed.

讨论了溶剂和介质对各个染料紫外可见吸收光谱及偶氮式异构体与腙式异构体互变平衡的影响。

In order to investigate the tautomerism of 5-fluorouracil (5-FU) induced by proton transfer, we describe a study of structural tautomer interconversion using density functional theory calculations at B3LYP/6-311++G level of the theory.

采用密度泛函理论B3LYP方法，在6-311++G基组上研究了由质子转移引起的5-氟尿嘧啶(5-Fu)的异构化反应。

The excited-state intramolecular proton transfer tautomerism reaction of 6-methyl-4-hydroxy pyri-midine monomers and dimmers was investigated by the ab initio method with the self-consistent reaction field with Tomas's polarized continuum mode and CIS theories at HF level on the basis of 6-311+G* and 6-31G basis set. By studying the potential energy surface, it was found that the monomer's ground-state proton transfer process together with the excited-state proton transfer process is a molecular system of four energy level, but dimmers were not, which can be used to explain the fact that UV-visible absorption and fluorescence spectra of monomer and dimers all corresponded to quinoid.

采用 ab initio HF理论的组态相关CIS方法和连续溶剂模型PCM，分别在6-311+G*和6-31G水平上研究了6-甲基-4-羟基嘧啶单体及二聚体激发态质子转移的异构化反应；对其反应势能面的研究发现，单体基态和激发态的异构化反应一起可以形成四能级的分子电子体系，而二聚体的却不能，由此解释了单体和二聚体的紫外吸收光谱和荧光发射光谱均对应于酮式构型的原因。

Then, by using another tautomer (2H-indazole form), all of the above processes were repeated to investigate the effect of tautomerism upon the QSAR modelling.

对所有化合物采用另一异构形式重复上述过程，以探讨互变异构对QSAR建模的影响。

It has been shown that tautomerism has a significant effect on the QSAR modelling, and the models obtained from 1H-indazol tautomeric form always represent higher quality than those from 2H-indazol tautomer, which indicates that 1H-indazol tautomer of the indazolyl urea is probably the active form when binding with the TRPV1 channel protein. It has also been demonstrated that the theoretical descriptors derived from electrostatic potentials on molecular surface together with the GETAWAY descriptors can be well used to express the quantitative structure-activity relationship of indazolyl urea TRPV1 channel antagonists.

结果表明：互变异构对QSAR结果具有一定的影响，采用1H-吲唑异构形式得到的模型，在质量上均高于采用2H-吲唑异构体，预示着1H-吲唑异构体更有可能是吲唑脲类分子的活性异构形式；分子表面静电势参数结合GETAWAY参数可以较好地用于描述TRPV1通道拮抗剂分子结构与其活性间的定量关系。

The B3LYP/6-31G** calculations on the tautomerism of clonidine in an aqueous medium using Onsager solvation theory model have shown that the solvent does not change the relative stability of the individual tautomers of this drug and the neutral molecule of clonidine exists as the more stable imino tautomer in the gas and aqueous phases.

Onsager反应场溶剂模型用于水相的计算。

The method based on CE is simple and fast, and can be used to study the kinetics of keto-enol tautomerism of other compounds.

所建立的方法简单、快速，可以被用于其他羰基化合物的烯醇互变动力学研究。

Tautomerism: Existence of two or more chemical compound s that have the same chemical composition but different structures and that convert easily from one to another.

互变异构体现象：两种或多种化合物，具有相同的化学组成，但结构不同，很容易从一种转换到另一种。

The reaction mechanism of thione-thiol tautomerism for 2,6-dithiopurine obtained from proton transfer has been investigated by DFT B3LYP method with 6-311＋G basis set. The reaction enthalpies, activation energies, activation free energies and the rate constants of tautomerism were obtained.

采用密度泛函B3LYP方法，在6-311＋G基组水平上对2，6-二巯基嘌呤质子转移引起的硫醇式与硫酮式互变异构反应进行了计算研究，获得了互变异构过程的反应焓、活化能、活化吉布斯自由能和质子转移反应的速率常数等性质。

She gently rebuff ed him, but agreed that they could be friends

她婉言拒绝了，但同意作为朋友相处。

If in the penal farm, you were sure to be criticized.

要是在劳改农场，你等着挨绳子吧！