一个阴离子全金属 σ-芳香 {Bi4} 环的超分子捕获
Ravi Yadav1,2, Avijit Maiti1, Marcel Schorpp3
1Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Heidelberg, Germany.
Nature chemistry
|May 17, 2024
概括
研究人员稳定了珠团,揭示了金属单环中的 σ-芳香性. 这一发现挑战了对较重元素的传统芳香度模型,强调了电荷分布的重要性.
科学领域:
- * 无机化学 无机化学
- * 材料科学 材料科学
- * 理论化学 理论化学
背景情况:
- *芳香性是有机化学中一个成熟的概念.
- * 在纯金属环系统中芳香度的作用和定义仍在争论中.
- * 超分子化学为稳定不寻常的无机结构提供了新的方法.
研究的目的:
- * 为了研究纯金属环系统的芳香度.
- * 为了探索一个电离子木团的超分子稳定.
- * 确定16价值电子四原子集群的结构偏好.
主要方法:
- * 一种稳定斯木形体的合成和结晶学表征.
- *光谱分析 (例如NMR,UV-Vis).
- * 量子化学计算,包括电子定位函数和磁诱导环流.
- * 对类似的p块元素集群进行计算选.
主要成果:
- * 通过使用calix[4]pyrrolato连接体,成功地对一个cationic {Bi4} rhomboid进行了超分子稳定.
- *实验和计算证据表明[Bi4]4+环中的σ-芳香性.
- *确定平面形作为16价值电子四原子集群在p块元素中的首选结构.
- *证明[Bi4]4+集群与抗芳香[Al4]4-.的同电子关系.
结论:
- * 这项研究提供了强有力的证据,证明金属单 bismuth 环的 σ-aromaticity.
- *诸如电荷同位素等微妙因素在较重的元素中显著影响芳香度与反芳香度.
- * Hückel模型的适用性对于较重的同源物是有限的,因此需要对芳香性辩论采取细微的方法.
相关概念视频
Metal-Ligand Bonds
20.7K
The hemoglobin in the blood, the chlorophyll in green plants, vitamin B-12, and the catalyst used in the manufacture of polyethylene all contain coordination compounds. Ions of the metals, especially the transition metals, are likely to form complexes.
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
20.7K
Complexation Equilibria: The Chelate Effect
505
In complexation reactions, metal atoms or cations interact with ligands to form donor-acceptor adducts called metal complexes. Ligands that bind through one donor site are monodentate, ligands with two donor sites are bidentate, and those with more than two donor sites are polydentate ligands. For example, ethylene diamine is a bidentate ligand that binds through two nitrogen donor atoms, forming a five-membered ring. EDTA is a polydentate ligand that binds through four oxygen and two nitrogen...
505
Valence 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
Radical Reactivity: Intramolecular vs Intermolecular
1.7K
Radical reactions can occur either intermolecularly or intramolecularly. In an intermolecular radical reaction, a nucleophilic radical adds to an electrophilic alkene or vice versa. In such reactions, the radical and generally the alkene, which is also called the radical trap, are two different molecules. Additionally, for such intermolecular reactions to occur, the radical trap must be active, present in an excess concentration, and the radical starting material must have a weak...
1.7K
Aromatic Hydrocarbon Cations: Structural Overview
2.8K
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...
2.8K
Complexation Equilibria: Factors Influencing Stability of Complexes
367
In complexation reactions, metal cations are the electron pair acceptors, and the ligands are the electron pair donors. The stability of the metal complexes depends primarily on the complexing ability of the central metal ion and the nature of the ligands. Generally, the complexing ability of the metal ion depends on the size and charge of the ion. As the metal ion size increases, the stability of the metal complexes decreases, provided that the valency of the metal ion and the ligands remain...
367


