解联体对转化催化剂活动的影响:鲁-氨基复合物的实验和计算研究
Crystal K Chu1, Tzu-Pin Lin1, Huiling Shao2
1Arnold and Mabel Beckman Laboratories of Chemical Synthesis , California Institute of Technology , Pasadena , California 91125 , United States.
Journal of the American Chemical Society
|April 7, 2018
概括
使用氨基联体的催化剂由于P-N结合而显示更快的启动率. 连接物结构显著影响了氨酸转化和聚合过程中的催化剂活性.
科学领域:
- 有机金属化学
- 催化剂
- 聚合物科学
背景情况:
- 催化剂对于甲基形成至关重要.
- 氨基素配体可以调节催化剂活性.
- 了解连接体解离是催化剂启动的关键.
研究的目的:
- 研究氨基联体结构对第二代烯转化催化剂的影响.
- 确定素分离和重新分离的速率.
- 与催化剂启动和活性相关联.
主要方法:
- 氨基素连接体结构的系统变化.
- 测定素分离 (k1) 和再分离 (k-1) 速率的动力学研究.
- 进行X射线结晶学和密度函数理论 (DFT) 计算.
- 环开放转化聚合 (ROMP) 的实验.
主要成果:
- 与原始复合物相比,纳入PN键加速催化剂启动.
- 三氨基) 素配体表现出更强的结合,改变了启动加速.
- 连接物解离受硬质,诱导和构造因素的影响.
- 在最快启动的催化剂中,对联体构造的变化至关重要.
- ROMP反应速度与催化剂启动速度有很好的相关性.
结论:
- 连接物结构极大地影响了催化剂的启动和活性.
- 氨基素连接物为催化剂设计提供可调节的特性.
- 计算和实验数据为开发更有效的催化剂提供了洞察力.
相关概念视频
Metal-Ligand Bonds
24.5K
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...
24.5K
Olefin Metathesis Polymerization: Acyclic Diene Metathesis (ADMET)
2.2K
Acyclic diene metathesis polymerization or ADMET polymerization involves cross-metathesis of terminal dienes, such as 1,8-nonadiene, to give linear unsaturated polymer and ethylene. As ADMET is a reversible process, the formed ethylene gas must be removed from the reaction mixture to complete the polymerization process.
Similar to cross-metathesis, ADMET also involves the formation of metallacyclobutane intermediate by [2+2] cycloaddition of one of the double bonds of a terminal diene with...
Similar to cross-metathesis, ADMET also involves the formation of metallacyclobutane intermediate by [2+2] cycloaddition of one of the double bonds of a terminal diene with...
2.2K
Olefin Metathesis Polymerization: Ring-Opening Metathesis Polymerization (ROMP)
3.2K
Ring-opening metathesis polymerization or ROMP involves strained cycloalkenes as starting materials. The mechanism of ROMP proceeds by reacting cycloalkene with Grubbs catalyst to give metallacyclobutane intermediate which undergoes a ring-opening reaction to form new carbene. The new carbene reacts with another molecule of cycloalkene. Repetition of these steps leads to the formation of an unsaturated open-chain polymer product. All these steps are reversible, however, relieving the ring...
3.2K
Ligand Binding and Linkage
5.6K
Allosteric proteins have more than one ligand binding site; the binding of a ligand to any of these sites influences the binding of ligands to the other sites. When a protein is allosteric, its binding sites are called coupled or linked. In the case of enzymes, the site that binds to the substrate is known as the active site and the other site is known as the regulatory site. When a ligand binds to the regulatory site, this leads to conformational changes in the protein that can influence...
5.6K
Ligand Binding Sites
15.2K
Proteins are dynamic macromolecules that carry out a wide variety of essential processes; however, the activities of most proteins depend on their interactions with other molecules or ions, known as ligands.
Protein-ligand interactions are quite specific; even though numerous potential ligands surround a cellular protein at any given time, only a particular ligand can bind to that protein. Moreover, a ligand binds only to a dedicated area on the surface of the protein, known as the...
Protein-ligand interactions are quite specific; even though numerous potential ligands surround a cellular protein at any given time, only a particular ligand can bind to that protein. Moreover, a ligand binds only to a dedicated area on the surface of the protein, known as the...
15.2K
Imaging Studies III: Computed Tomography
406
DefinitionComputed Tomography (CT) of the genitourinary (GU) tract is a non-invasive imaging modality that utilizes X-rays and computer processing to generate detailed cross-sectional images of the urinary system, encompassing the kidneys, ureters, bladder, and adjacent structures such as the adrenal glands.PurposeCT scans of the GU tract serve several diagnostic and therapeutic purposes, including:Diagnosis of Urinary Tract Diseases: Detects kidney stones, tumors, cysts, and congenital...
406


