相关实验视频
Updated: May 2, 2026
09:56
Hierarchical and Programmable One-Pot Oligosaccharide Synthesis
Published on: September 6, 2019
7.2K
纯氧化 (Cs+/XeCryptophane) FeII 层次结构
Dawei Zhang1, Tanya K Ronson1, Jake L Greenfield1
1Department of Chemistry , University of Cambridge , Lensfield Road , Cambridge CB2 1EW , U.K.
Journal of the American Chemical Society
|April 30, 2019
概括
研究人员使用自组合的铁 (II) 囊来封装共价加密. 这种等级系统展示了受控的客体结合和立体化学信息传输,影响了分子识别和超分子化学.
科学领域:
- 超分子化学
- 材料科学
- 化学结晶学
背景情况:
- 层次化嵌套的主机可以精确控制内部空洞中的客户互动.
- 自组装的囊为复杂的分子架构提供可调节的平台.
- 对于高级功能材料来说,研究多组件系统中的层间通信至关重要.
研究的目的:
- 构建和描述一个新中的超分子复合体.
- 探索层次系统的客体结合特性和立体化学行为.
- 展示从一个内共价到一个外自组装囊的立体化学信息传输.
主要方法:
- 自组装一个基于三素的Fe (II) 4L4囊.
- 在Fe (II) 4L4囊中封装加密-111 (CRY).
- 为了确定俄罗斯娃娃复合体的结构,
- 用离子和原子进行结合性研究.
- 通过对抗纯CRY进行选择性结合实验.
主要成果:
- 一个自组装的Fe(II) 4L4囊成功封装了共价加密-111 (CRY) .
- 与单独的CRY相比,由此产生的子内复合体对Cs+和Xe等客体具有改变的结合亲和力.
- X射线结晶学证实了Cs+在[CRY]Fe(II) 4L4复合体中的封装,显示了外上的异常8+电荷.
- 在对四面体的 enantiopure CRY 结合中观察到高的 enantioselectivity (530 倍).
- 发生了立体化学信息传递,导致[客CRY]Fe(II) 4L4复合体,即使在客人交换后,立体化学也持续存在.
结论:
- Fe(II) 4L4囊作为共价CRY的有效宿主,创建了一个功能层次系统.
- 内架构允许调节客体结合,并证明立体化学信息的传输.
- 这项工作为设计复杂的超分子系统提供了一个新的平台,
相关概念视频
02:42Ionic Crystal Structures
18.0K
Ionic crystals consist of two or more different kinds of ions that usually have different sizes. The packing of these ions into a crystal structure is more complex than the packing of metal atoms that are the same size.
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
18.0K
02:52Stereoisomerism
11.1K
Isomerism in Complexes
Isomers are different chemical species that have the same chemical formula.
Transition metal complexes often exist as geometric isomers, in which the same atoms are connected through the same types of bonds but with differences in their orientation in space. Coordination complexes with two different ligands in the cis and trans positions from a ligand of interest form isomers. For example, the octahedral [Co(NH3)4Cl2]+ ion has two isomers (Figure 1) In the cis...
Isomers are different chemical species that have the same chemical formula.
Transition metal complexes often exist as geometric isomers, in which the same atoms are connected through the same types of bonds but with differences in their orientation in space. Coordination complexes with two different ligands in the cis and trans positions from a ligand of interest form isomers. For example, the octahedral [Co(NH3)4Cl2]+ ion has two isomers (Figure 1) In the cis...
11.1K
02:58Crystal Field Theory - Octahedral Complexes
28.4K
Crystal Field Theory
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
28.4K
02:21Naming Enantiomers
18.9K
The naming of enantiomers employs the Cahn–Ingold–Prelog rules that involve assigning priorities to different substituent groups at a chiral center. Each enantiomer, being a distinct molecule, is assigned a unique name by the Cahn–Ingold–Prelog (CIP) rules, also called the R–S system. The prefix R- or S- attached to the chiral centers in an enantiomer is dependent on the spatial arrangement of the four substituents on the chiral center. The R–S system...
18.9K
02:30Chirality at Nitrogen, Phosphorus, and Sulfur
5.5K
Chirality is most prevalent in carbon-based tetrahedral compounds, but this important facet of molecular symmetry extends to sp3-hybridized nitrogen, phosphorus and sulfur centers, including trivalent molecules with lone pairs. Here, the lone pair behaves as a functional group in addition to the other three substituents to form an analogous tetrahedral center that can be chiral.
A consequence of chirality is the need for enantiomeric resolution. While this is theoretically possible for all...
A consequence of chirality is the need for enantiomeric resolution. While this is theoretically possible for all...
5.5K
02:05Prochirality
4.0K
The concept of prochirality leads to the nomenclature of the individual faces of a molecule and plays a crucial role in the enantioselective reaction. It is a concept where two or more achiral molecules react to produce chiral products. A typical process is the reaction of an achiral ketone to generate a chiral alcohol. Here, the achiral reactant reacts with an achiral reducing agent, sodium borohydride, to generate an equimolar mixture of the chiral enantiomers of the product. For example, an...
4.0K