A [3]含有素的环连接II:合成,结构和光谱研究
Selena J Lockyer1, Lubomir Loci1, George F S Whitehead1
1Department of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK.
Chemistry (Weinheim an der Bergstrasse, Germany)
|September 30, 2025
概括
研究人员使用新型构建块合成了扩展混合有机-无机罗塔克桑. 这些具有铜复合体的结构形成了扩展的 [3] 罗塔克桑和 [2] 罗塔克桑,它们的组合由硬质因子控制并通过光谱学证实.
科学领域:
- 超分子化学 超分子化学
- 材料科学 材料科学 材料科学
- 协调化学 协调化学
背景情况:
- 对于先进的材料来说,开发像轮素这样的复杂分子结构至关重要.
- 混合有机-无机材料通过结合不同的化学实体来提供独特的特性.
- 控制分子组件的自我组装是超分子化学的一个关键挑战.
研究的目的:
- 为了合成和表征扩展的杂交有机-无机罗塔克桑.
- 为了研究线程结构对罗塔xane 形成和架构的影响.
- 探索溶液中的这些罗塔克桑的结构完整性和动态.
主要方法:
- 阴离子宏循环和二次线构建块的合成.
- 与铜 (II) 二氧化 (hexafluoroacetylacetonate) ([Cu (hfac) 2]) 发生反应,形成轮复合物.
- 使用单晶X射线晶体学和双电子共振 (DEER) 光谱学进行表征.
主要成果:
- 成功合成了扩展的 [3]rotaxane ({[Cu(hfac) 2]3[1]2}) 和 [2]rotaxane ({[Cu(hfac) 2]2[3]}) 的合成.
- 有机线程臂的绝缘要求决定了最终的罗塔xane 结构.
- 在 [3]rotaxane.中观察到一个线性Cu...Cu...Cu碎片,分离31.3 Å.
- 德尔光谱学证实了溶液中的结构完整性,并揭示了动态重排.
结论:
- 扩展的杂交有机-无机罗塔克桑可以被可控合成.
- 有机线程的分子设计对于指导自我组装至关重要.
- 这些轮素在溶液中表现出稳定的结构,有动态行为的证据.
相关概念视频
01:18Aromatic Hydrocarbon Cations: Structural Overview
3.6K
Cycloheptatriene is a neutral monocyclic unsaturated hydrocarbon that consists of an odd number of carbon atoms and an intervening sp3 carbon in the ring. The three double bonds in the ring correspond to 6 π electrons, which is a Huckel number, and therefore satisfies the criteria of 4n + 2 π electrons. However, the intervening sp3 carbon disrupts the continuous overlap of p orbitals. As a result, cycloheptatriene is not aromatic.
Removing one hydrogen from the intervening CH2 group...
Removing one hydrogen from the intervening CH2 group...
3.6K
01:17Thermal Electrocyclic Reactions: Stereochemistry
2.5K
The stereochemistry of electrocyclic reactions is strongly influenced by the orbital symmetry of the polyene HOMO. Under thermal conditions, the reaction proceeds via the ground-state HOMO.
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
2.5K
01:26Thermal and Photochemical Electrocyclic Reactions: Overview
2.9K
Electrocyclic reactions are reversible reactions. They involve an intramolecular cyclization or ring-opening of a conjugated polyene. Shown below are two examples of electrocyclic reactions. In the first reaction, the formation of the cyclic product is favored. In contrast, in the second reaction, ring-opening is favored due to the high ring strain associated with cyclobutene formation.
2.9K
02:02Chair Conformation of Cyclohexane
17.8K
The chair conformation is the most stable form of cyclohexane due to the absence of angle and torsional strain. The absence of angle strain is a result of cyclohexane’s bond angle being very close to the ideal tetrahedral bond angle of 109.5° in its chair conformer. Similarly, the torsional strain is also absent owing to the perfectly staggered arrangement of bonds.
The hydrogen atoms linked to carbons are arranged in two different axial and equatorial orientations to achieve this...
The hydrogen atoms linked to carbons are arranged in two different axial and equatorial orientations to achieve this...
17.8K
02:33Stereoisomerism of Cyclic Compounds
10.8K
In this lesson, we delve into the role of ring conformation and its stability, which determines the spatial arrangement and, consequently, the molecular symmetry and stereoisomerism of cyclic compounds. 1,2-Dimethylcyclohexane is used as a case study to evaluate the possible number of stereoisomers. Here, given the multiple (n = 2) chiral centers, there are 2n = 4 possible configurations that lack a plane of symmetry, as the ring skeleton exists in a non-planar chair conformation. In addition,...
10.8K
01:26Photochemical Electrocyclic Reactions: Stereochemistry
2.2K
The absorption of UV–visible light by conjugated systems causes the promotion of an electron from the ground state to the excited state. Consequently, photochemical electrocyclic reactions proceed via the excited-state HOMO rather than the ground-state HOMO. Since the ground- and excited-state HOMOs have different symmetries, the stereochemical outcome of electrocyclic reactions depends on the mode of activation; i.e., thermal or photochemical.
Selection Rules: Photochemical Activation
Selection Rules: Photochemical Activation
2.2K