双和三旋混合无机有机 [2]含有金属化盐基组的罗塔克桑
Tom S Bennett1, Selena J Lockyer1, Deepak Asthana1
1Department of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road, Manchester, M13 9PL, United Kingdom.
Chemistry, an Asian journal
|June 19, 2024
概括
合成和表征了具有金属盐复合物的新 [2] 罗塔克桑. 这些分子含有偏磁金属离子和{Cr7Ni}环,使用电子偏磁共振 (EPR) 光谱学进行了研究.
科学领域:
- 超分子化学 超分子化学
- 协调化学 协调化学
- 磁共振光谱学 磁共振光谱学
背景情况:
- 罗塔克桑是机械互锁的分子,在分子机器和材料科学中具有潜在的应用.
- 盐联体是多功能合剂,能够协调各种金属离子,影响它们的磁性和电子性质.
- 电子磁共振 (EPR) 光谱是一种强大的技术,用于研究磁共振物种及其相互作用.
研究的目的:
- 为了合成新的单盐和双盐功能化 [2] 罗塔克桑.
- 通过X射线衍射和EPR光谱学来描述这些罗塔克桑的结构和磁性特性.
- 通过使用先进的EPR技术,研究包含多个偏磁中心的系统中的旋转-旋转相互作用.
主要方法:
- 通过用salen前体对结末线进行化,合成 [2]rotaxanes.
- 使用单晶X射线衍射 (XRD) 进行结构确定.
- 固态和溶液电子偏磁共振 (EPR) 谱学,包括脉冲双极 EPR 技术 (DEER/PELDOR,RIDME).
主要成果:
- 成功合成了单盐和双盐功能化 [2] 罗塔克桑,其中包含一个 [Cr7NiF8(O2C tBu) 16] - 环.
- 具有自由基或金属化基组 (M=Cu2+,Ni2+, (VO) 2+) 的罗塔克桑的结构确认和磁性表征.
- 在具有偏磁M离子和S=1/2 {Cr7Ni} 环的轮中展示了三旋系统 (S=1/2),测量的M-M和M-{Cr7Ni} 距离与XRD一致.
结论:
- 合成的[2]rotaxanes为研究机械互锁分子系统中的复杂磁相互作用提供了一个平台.
- 脉冲双极EPR光谱在探测多旋转旋系统中的旋转旋相互作用和距离方面是有效的.
- 结果突出了基于罗他素的系统在开发先进的磁性材料和分子装置方面的潜力.
更多相关视频
19:58Palladium N-Heterocyclic Carbene Complexes: Synthesis from Benzimidazolium Salts and Catalytic Activity in Carbon-carbon Bond-forming Reactions
Published on: July 30, 2017
9.6K
09:45Accessing Valuable Ligand Supports for Transition Metals: A Modified, Intermediate Scale Preparation of 1,2,3,4,5-Pentamethylcyclopentadiene
Published on: March 20, 2017
10.4K
相关概念视频
02:42Valence Bond Theory
8.5K
Coordination compounds and complexes exhibit different colors, geometries, and magnetic behavior, depending on the metal atom/ion and ligands from which they are composed. In an attempt to explain the bonding and structure of coordination complexes, Linus Pauling proposed the valence bond theory, or VBT, using the concepts of hybridization and the overlapping of the atomic orbitals. According to VBT, the central metal atom or ion (Lewis acid) hybridizes to provide empty orbitals of suitable...
8.5K
01:20Spin–Spin Coupling: Two-Bond Coupling (Geminal Coupling)
998
Two NMR-active nuclei bonded to a central atom can be involved in geminal or two-bond coupling. Geminal coupling is commonly seen between diastereotopic protons in chiral molecules and unsymmetrical alkenes, among others.
The central atom need not be NMR-active because its electrons are affected by the electron polarization of the spin-active atoms. However, spin information is transmitted less effectively than in one-bond coupling, and 2J values are usually weaker than 1J values. The energy of...
The central atom need not be NMR-active because its electrons are affected by the electron polarization of the spin-active atoms. However, spin information is transmitted less effectively than in one-bond coupling, and 2J values are usually weaker than 1J values. The energy of...
998
02:34Structural Isomerism
19.2K
Isomerism in Complexes
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly, SCN− can...
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly, SCN− can...
19.2K
01:22Spin–Spin Coupling: Three-Bond Coupling (Vicinal Coupling)
1.1K
Vicinal or three-bond coupling is commonly observed between protons attached to adjacent carbons. Here, nuclear spin information is primarily transferred via electron spin interactions between adjacent C‑H bond orbitals. This generally favors the antiparallel arrangement of spins, so 3J values are usually positive.
The extent of coupling depends on the C‑C bond length, the two H‑C‑C angles, any electron-withdrawing substituents, and the dihedral angle between the...
The extent of coupling depends on the C‑C bond length, the two H‑C‑C angles, any electron-withdrawing substituents, and the dihedral angle between the...
1.1K
![[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2Ffiles%2Fmedia%2Fscience-education%2Fscience-education-thumbs%2F12417.jpg&w=3840&q=75)
01:16[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction
10.1K
The Diels–Alder reaction is an example of a thermal pericyclic reaction between a conjugated diene and an alkene or alkyne, commonly referred to as a dienophile. The reaction involves a concerted movement of six π electrons, four from the diene and two from the dienophile, forming an unsaturated six-membered ring. As a result, these reactions are classified as [4+2] cycloadditions.
10.1K
02:38Electrophilic Addition to Alkynes: Halogenation
8.2K
Introduction
Halogenation is another class of electrophilic addition reactions where a halogen molecule gets added across a π bond. In alkynes, the presence of two π bonds allows for the addition of two equivalents of halogens (bromine or chlorine). The addition of the first halogen molecule forms a trans-dihaloalkene as the major product and the cis isomer as the minor product. Subsequent addition of the second equivalent yields the tetrahalide.
Halogenation is another class of electrophilic addition reactions where a halogen molecule gets added across a π bond. In alkynes, the presence of two π bonds allows for the addition of two equivalents of halogens (bromine or chlorine). The addition of the first halogen molecule forms a trans-dihaloalkene as the major product and the cis isomer as the minor product. Subsequent addition of the second equivalent yields the tetrahalide.
8.2K