金属调节的连接物反应性使得CX2 (X = O,S) 与观众Cu中心的同
M Victoria Lorenzo Ocampo1, Leslie J Murray1
1Center for Catalysis, Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200, United States.
Journal of the American Chemical Society
|January 2, 2024
概括
这项研究表明,催化中的配体可以作为反应中心,而不仅仅是电子储存库. 一个铜-硫复合体在二硫化碳反应中证明了基于联体的碳-碳键的形成,展示了金属-联体的合作性.
科学领域:
- 有机金属化学
- 催化剂
- 协调化学
背景情况:
- 在合成复合物中,联体非无罪,即联体在电子捐赠之外积极参与催化,至关重要.
- 化学非无罪性可能涉及基质激活和储存/中继物种,如质子 (H+) 在配体位点.
- 了解基于联体的反应性是设计新型催化系统的关键.
研究的目的:
- 为了研究二氧化碳减氧催化剂[K(THF) 3) ((Cu3SL) 与二硫化碳 (CS2) 的反应性.
- 探索联体非无罪在C-C键形成中的作用.
- 阐明 CS2 吸附物形成的机制及其对二氧化碳减排的相关性.
主要方法:
- 铜-硫复合体在不同的条件下与CS2的反应.
- 进行X射线衍射分析以确定CS2的结构.
- 热力学参数的确定和易斯酸度效应的研究.
- 密度功能理论 (DFT) 的计算和同位素标记研究.
主要成果:
- 根据反应时间和CS2度,观察到四氧化或CS2连接物添加物的形成.
- X射线衍射证实了CS2与联体骨干的结合,没有明显的金属参与.
- 热力学研究表明,更多的易斯酸有利于形.
- DFT研究和同位素标记证实了添加剂在二氧化碳减排中的相关性,并确定了同合的异构素产物.
结论:
- 该系统表明化学非无辜性超出了H+储存到C-C键的形成,通过基于配体的反应性.
- 这项工作代表了金属-连接体合作的罕见例子,其中连接体作为与观众金属离子的反应中心.
- 这些发现为设计连接物在基质转化中发挥积极作用的催化剂提供了新的见解.
相关概念视频
Metal-Ligand Bonds
20.8K
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...
20.8K
Complexation Equilibria: The Chelate Effect
518
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...
518
Crystal Field Theory - Octahedral Complexes
26.6K
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...
26.6K
Complexation Equilibria: Factors Influencing Stability of Complexes
372
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...
372
Valence Bond Theory
8.6K
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...
8.6K
Complexometric Titration: Ligands
954
Different monodentate and polydentate ligands are used as complexing agents in complexometric titration reactions. The formation of complexes by mono- and bidentate ligands involves two or more intermediate steps, limiting their use as complexing agents. In comparison, polydentate ligands can form complexes with metal ions in a single-step process, facilitating sharper end points. This means polydentate ligands, such as amino carboxylic acid derivatives, are most commonly employed in...
954


