相关实验视频
Updated: Oct 10, 2025

11:41
Magnetic Tweezers for the Measurement of Twist and Torque
Published on: May 19, 2014
23.4K
无限:一个螺旋扭曲的图形八 [12] 循环烯拓体
Maciej Krzeszewski1, Hideto Ito1, Kenichiro Itami1,2
1Department of Chemistry, Graduate School of Science, Nagoya University, Nagoya 464-8602, Japan.
Journal of the American Chemical Society
|December 15, 2021
概括
研究人员合成了一种由12个环结合而成的无限分子. 这种独特的纳米碳结构表现出有趣的光物理性质,并且可以分成反体.
科学领域:
- 分子纳米碳
- 有机化学
- 超分子化学
背景情况:
- 开发具有独特拓的新分子纳米碳结构对于推进基础科学和实际应用至关重要.
- 循环聚烯提供了多种结构可能性,有助于探索新型碳基.
研究的目的:
- 报告了一种新型无限形聚烯的合成和特征,命名为无限 (1).
- 研究这种独特的分子纳米碳的结构性,光物理性和光学性.
主要方法:
- 合成涉及通过史蒂文斯重组将二氧化转化为环氧化,其次是其S,S'-bis (氧) 的热解和随后的光环化.
- 通过X射线结晶学得到结构确认.
- 使用紫外线吸收和光光谱学研究光物理性质,并补充密度功能理论计算. 使用状高性能液态染色法 (HPLC) 来分离反体,测量循环二极化 (CD) 和循环极化发光 (CPL).
主要成果:
- 无极 (1),cyclo[c.c.c.c.c.e.e.e.e.e]dodecakisbenzene,被合成为一个具有绿色光的稳定黄色固体.
- 通过X射线结晶学证实了它的8分子结构,
- 无限素 (1) 呈现中等圆形二极化 (CD) 和圆极化发光 (CPL) 值,并且其反体已成功分离.
结论:
- 无限 (1) 的成功合成扩展了具有复杂拓性的分子纳米碳素库.
- 这项研究突出了无限的独特结构和光物理特性,为材料科学提供了应用潜力.
- 无限的结构稳定性和手术性质使其成为一种有前途的超分子化学候选物.
相关概念视频
DNA Topoisomerases
32.8K
Topoisomerases are enzymes that relax overwound DNA molecules during various cell processes, including DNA replication and transcription. These enzymes regulate positive and negative DNA supercoiling without changing the nucleotide sequence. DNA overwinding in a clockwise direction results in positively supercoiled DNA, whereas underwinding in a counterclockwise direction produces negatively supercoiled DNA.
Types and Mechanism of action
Topoisomerases are divided into two main types. ...
Types and Mechanism of action
Topoisomerases are divided into two main types. ...
32.8K
Conformations of Cyclohexane
13.8K
Cyclohexane does not exist in a planar form due to the high angle and torsional strain it would experience in the planar structure. Instead, it adopts non-planar chair and boat conformations.
The chair form is the most stable and derives its name from its resemblance to the “easy chair.” In the chair conformation, two carbon atoms are arranged out-of-plane — one above and one below, minimizing the torsional strain. In the chair form, the bond angle is very close to the ideal...
The chair form is the most stable and derives its name from its resemblance to the “easy chair.” In the chair conformation, two carbon atoms are arranged out-of-plane — one above and one below, minimizing the torsional strain. In the chair form, the bond angle is very close to the ideal...
13.8K
Chair Conformation of Cyclohexane
16.2K
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...
16.2K
Stereoisomerism of Cyclic Compounds
9.8K
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,...
9.8K
Aromatic Hydrocarbon Cations: Structural Overview
3.2K
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...
3.2K
Unsymmetric Bending
512
Unsymmetrical bending occurs when the bending moment applied to a structural member does not align with its principal axis. This misalignment leads to complex stress distributions and deflection patterns that differ from those in symmetrical bending, and are essential for designing structures to withstand different loading conditions. In unsymmetrical bending, the neutral axis—where stress is zero—does not necessarily align with the geometric axes of the cross-section. The...
512

