查询词典 lewis acid

Another is the Lewis definition (also 1923): An acid is a chemical that can accept an electron pair from a base, which they share to form a covalent bond.

另一种理论是路易斯理论(也是在1923年发表)：酸就是能由碱接受一个电子对形成一个共价键的化学物质。

We screened a set of Lewis base organocatalysts derived from chiral pipecolinic acid and tert-butanesulfinamide for the reduction of-N-Cbz-1- phenylpropenamine, including newly designed ones and some of those previously developed in our lab. However, only moderate stereoselectivities, albeit high yields were obtained.

在本课题组前期研究的基础上，我们筛选并设计了一系列以手性哌啶酸和叔丁基亚磺酰胺为母体的有机小分子路易斯碱催化剂，它们能催化三氯氢硅对-N-苄氧羰基-1-苯基丙烯胺的不对称还原，获得很高的收率和中等的对映选择性，并且具有很好的底物普适性。

Starting from chiral proline, pipecolinic acid, piperazine-2-carboxylic acid and 1,2-diphenyl amino alcohol, a series of structurally simple and easily prepared amides were developed as highly effective Lewis basic organocatalysts for the asymmetric reduction of imines with trichlorosilane as the reducing agent, which promoted the reduction of N-aryl imines with high yields and excellent enantioselectivities with an unprecedented substrate spectrum.

本文分别由手性脯氨酸、哌啶酸、哌嗪酸以及氨基醇出发，设计和合成了一系列结构新颖、合成简便、性能优良的酰胺类有机小分子路易斯碱催化剂，以廉价的三氯氢硅为氢源，用这些催化剂催化亚胺不对称还原，得到了非常优良的收率、对映选择性和前所未有的底物普适性。

The Lewis base property of MgO was studied quantitatively by infrared spectroscopy with boric acid trimethyl ester as the molecular probe.

采用硼酸三甲酯作为探针分子对MgO的路易斯碱性进行了红外光谱定量研究。

The Soft-Hard Acid-Base Theory was used to interpret the experimental results for the first time, the softness of sulfur, which was a Lewis base, was changed by solvents, and the reactivity of sulfur atom was changed.

结果表明，砷化镓表面硫化层厚度与所用溶液的极性有关，用极性小的有机醇作溶剂可以得到更厚的硫钝化层。

An ate complex is a salt formed by reaction of a Lewis acid with a base whereby the central atom increases its valence.

酸根型配合物是指路易斯酸與特定的鹼生成的中心原子價升高的鹽。

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。