查询词典 monosubstituted

Among the open-chain crown ethers and cryptands with a same structure, the compounds disubstituted at the amide nitrogen atoms show the larger extractability for Am and Eu than the monosubstituted ones. The compounds disubstituted at the amide nitrogen atoms by two phenyl groups show the larger extractability for Am and Eu than those by two alkyl groups.

3在结构相同的开链冠醚和开链穴醚中，酰胺氮原子上二取代化合物对Am和Eu的萃取能力大于一取代化合物；酰胺氮原子上两个取代基都是苯基的化合物对Am和Eu的萃取能力大于两个取代基都是烷基的化合物。

Four different ionic liquids, BF4, BF and PF6 were investigated, arid PF6 showed the best effect when used as the reaction media, giving the highest yield in the shortest reaction time. Promoted by KF in PF6, N-aryl or N-alkyl monosubstituted sulfonamides could react with various activated halides and unactivated primary halides smoothly. Reactions were performed at 85℃ for 2~10 hours, and thirteen N-alkylation products were obtained with 70%~97% yields. Moreover, the ionic liquid recovered could be reused for three times with no appreciable decrease in yield and reaction rate.

结果表明，以PF6为反应介质时显示出了最好的效果，反应的时间最短，收率最高。N-芳基或N-烷基单取代的磺酰胺和各类不同结构的活化的卤代烃和未活化的一级卤代烃在PF6中KF作用下，85℃反应2~10h，以70%~97%的优良收率得到了13个N-烷基化产物，而且离子液体回收使用3次后效果未降低。

Firstly, a series of organic molecules which use phthalimido group as electron acceptor, N as electron donor, COO~- as eletrofugal group were synthesized based on SET-promoted photocyclization processes. These compounds were irradiated by 500 W ultraviolet under nitrogen atmosphere in room temperature. After filtration of the photochemical character of these molecules, substrate S1 and S2 were selected as appropriate model reactants. Secondly, the monosubstituted derivatives at the 6-position ofβ-cyclodextrin were synthesized as chiral template of photocyclization.

首先，以单电子转移机理为指导，设计了一系列以邻苯二甲酰亚胺基为电子受体、N为电子给体、羧基为离去基团的光环合反应底物，这些化合物在氮气保护下以500瓦紫外光室温下进行光照反应，对这一系列的分子的反应情况进行了研究与筛选，最终选择底物S1和S2作为研究光环合反应中立体控制方法的模型底物；其次，又合成了一系列6-位单取代β-环糊精，以此作为光环合反应的手性模板。

The analytical results have shown that p ro ducts mainly consisted of some monosubstituted, disubstituted and a few trisub stituted naphthalenes. Except the low activity of HZSM-5 catalyst, all other z eolite catalysts have higher activity. HY and Hβ catalytic activities were the highest, and their naphthalene conversions attained to 79.12 and 55.79 percent respectively, but their selectivities for 2-isopropylnaphthalene, 2,6-diisopropylnaphthalene(2,6-DIPN) and 2,7-diisopropylnaphthalene ( 2,7-DIPN) were too low. ZM catalysts had good activity and much better selecti vity, especially for ZM4-3, of which its 2,6-DIPN/2,7-DIPN ratio was 2.97. Th er efore, some zeolite catalysts are recommended for shape selective isopropylat ion of coal tar naphthalene.

研究结果表明，煤焦油萘异丙基化产物主要由一取代萘、二取代萘以及少量三取代萘组成；除HZSM-5活性较低以外，其它催化剂均有较高的反应活性，其中HY和Hβ反应活性最高，萘转化率分别达75.15％和55.96％，但β位产物的选择性较差；ZM类催化剂既有一定的活性，又有较高的β选择性，是萘择形异丙基化反应理想的备选催化剂。

Additionally, we reported on the reactions between alkyl halides and cyclic imides, N-monosubstituted sulfonamides, 2-mercaptobenzothiazole or sodium arenesulfinates respectively.

正文部分中介绍了本论文实验工作的二个主要部分组成：一、离子液体中O、N、S等杂原子烷基化反应研究；二、离子液体中的Knoevenagel缩合及其相关反应研究。

The central 5, 5'-disubstituted bipyridine units of each ligand coordinate theNi or Fe ion, while all the terminal 6-monosubstituted bipyridine units of the ligands keep free of coordination, as the result trinuclear triple-stranded helicate 〓 can not form. This is considered to be caused by the steric hindrance of the methylene substituents α to the chelating nitrogens of the terminal bipyridine units and the strain caused by linkage mode.

配体L〓与Ag作用得到〓，两个配体链相互缠绕着两个Ag离子周围形成双股螺旋结构并以头尾式排列(见图3)，由于配体中位于配位N原子α或β位的末端甲基或次甲基取代基的空间位阻阻碍了头对头式异构体的形成，也正是由于配体头尾式排列而使Ag双股螺旋得以形成，这一结果表明该螺旋体的组装过程中自发地采取了空间阻碍尽可能小的那个构型。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。