查询词典 Lewis base

All the Lewis base ion and molecule which can supply duplet to coordinate with Cr〓 as ligand. Cr〓 also has another special property, its hydrate will bond together to form multi-core complex compound by hydroxy glycidic when the concentration is properly.

含铬外加剂利用Cr〓的特点，在一定浓度下除了自身缩合形成多核络合物外，还可吸附在矿料表面，在加热条件下，与酸性集料表面的羟基缩合，通过氧桥与矿料表面键合。

The results showed that MgO has a certain strength of Lewis base, and the adsorption of BATE on MgO is monomolecular chemical adsorption.

结果表明MgO有一定的路易斯碱强度，与硼酸三甲酯之间的吸附是单分子层化学吸附。

And also, we unexpectedly discovered a ring-opening reaction of aziridines or epoxides with iodine promoted by thiophenol.

我们认为，在反应中，DMSO自身作为一种Lewis Base，能有效活化亲核试剂，从而促进反应的顺利进行。

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。

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。

In addition, in-situ infrared spectroscopy provides the information about the nature of the surface acid and base sites. For example, Lewis acid and base sites on metal oxides are coordinatively unsaturated metal cations and oxygen anions, respectively, while Brinsted acid and base sites are the hydroxyl groups on the surface.

结合原位红外光谱，还能够详细地了解表面酸碱中心的性质：金属氧化物表面的Lewis酸中心和碱中心分别是表面配位不饱和的金属离子和氧负离子， Brinsted酸中心和碱中心则是金属氧化物表面的羟基。

After the failure of achieving good enatioselectivity in asymmetric Baylis-Hillman reaction, we turned our attention to traditional chiral Lewis base catalyzed asymmetric Baylis-Hillman reaction.

我们还发现，用咪唑与-脯氨酸共催化醛和丁烯酮的Baylis-Hillman反应，但产物的e.e值还是很低，因此又回到了传统的用手性Lewis碱催化不对称Baylis-Hillman反应研究中。

The result indicates that the big π bond of benzene not only turns benzene into a Lewis base,but also makes it to undergo electrophilic substitution (halogenation,nitration,sulfonation and so on),rather than addition

结果表明，苯的环状大π键结构不仅使苯成为1个Lewis碱，而且使苯容易发生卤代、硝化、磺化等亲电取代反应，但不易发生加成反应。

The optimum conditions for this reaction were confirmed: the mole ratios of the Lewis base and AlCl〓 with the electron-rich aromatic monomer are 1. 2 and 3. 4, respectively; 1, 2-dichloride ethane is the most suitable solvent in this reaction; The solution of the two reactants must be added slowly to a large amount of solvent containing catalyst under pseudo-high dilution conditions; The Lewis base, such as NMP, DMF are applicable in this reaction system.

在此理论的指导下，通过对单体结构的模拟，高选择性地合成了一种新型结构的芳香环状聚硫酯二聚体，对其结构进行了精确的表征，在不同溶剂中得到了该环状二聚体的单晶，单晶X-ray衍射表明该二聚体为环张力极小的大环化合物。

Isobutane can be chemisorbed on surface terminal oxygen of Lewis base sites M=O bonds by one or two H atoms in-CH〓.

异丁烷分子以CH〓中C-H键的H端单位或双位吸附于催化剂表面Lewis碱M=O双键的端氧位。

Since historical times,England ,where the early inhabitants were Celts, has been conquered three times .

从有历史以来，英国，在此地早期居住的是凯尔特人，已经被征服了三次。

Bluetooth OBEX File Transfer Enables the sending and receiving of files on your phone via Bluetooth.

蓝牙OBEX文件移动允许经过蓝牙传送和接受文件。。。。