在二维-基框架中利用结构动力学,在扩散有限的金属交换反应中显著加速金属运输
Lujia Liu1, Liang Li1,2, Jordan A DeGayner1
1Department of Chemistry , Northwestern University , 2145 Sheridan Road , Evanston , Illinois 60208-3113 , United States.
Journal of the American Chemical Society
|August 1, 2018
概括
在金属有机框架 (MOF) 中的合成后金属交换被框架动态加速. 操纵晶体溶解增强了离子传输,提高了MOF合成效率和产品的纯度.
科学领域:
- 材料科学
- 化学学
- 晶体学
背景情况:
- 合成后的金属交换对于合成新型金属有机框架至关重要.
- 在MOF结构中的离子传输是这一过程的关键,但未被充分探索的方面.
- 之前的研究专注于转移,忽视了离子扩散的作用.
研究的目的:
- 在二维-基化物中研究金属离子在合成后交换的运输机制.
- 阐明框架动态对离子扩散和交换效率的影响.
- 探索增强MOF中的金属交换策略.
主要方法:
- 用X射线结晶学来确定结构变化和离子位置.
- 电子显微镜用于可视化框架形态.
- 用于元素分析和量化金属交换的能量散射X射线光谱.
主要成果:
- 外源Co2+和Zn2+离子主要通过沿c轴的1D通道扩散,这是速度限制的步骤.
- 框架具有可逆的结构动态,在解溶时收缩,在溶解时扩张.
- 部分溶解的MOF晶体在金属运输中表现出高达2000倍的加速,从而提高纯度和更高的交换分数.
- 在完全溶解的晶体中,金属交换产生了具有独特的二维梯度垂直异构的中间体.
结论:
- 框架动态显著影响并可以加速MOF中的合成后金属交换.
- 控制晶体溶解是一种可行的策略,以增强离子传输和改善MOF合成.
- 这项工作揭示了通过动态结构操纵来设计和合成MOF材料的新可能性.
更多相关视频
04:51Author Spotlight: Functionalizing Metal-Organic Frameworks: Advancements, Challenges, and the Power of Post-Synthetic Ligand Exchange
Published on: June 23, 2023
4.2K
14:44Structure and Coordination Determination of Peptide-metal Complexes Using 1D and 2D 1H NMR
Published on: December 16, 2013
10.1K
相关概念视频
Alkali Metals
24.8K
Group 1 elements are soft and shiny metallic solids. They are malleable, ductile, and good conductors of heat and electricity. The melting points of the alkali metals are unusually low for metals and decrease going down the group, while the density increases going down the group with the exception of potassium (Table 1).
Table 1: Properties of the alkali metals
Table 1: Properties of the alkali metals
24.8K
Metallic Solids
20.8K
Metallic solids such as crystals of copper, aluminum, and iron are formed by metal atoms. The structure of metallic crystals is often described as a uniform distribution of atomic nuclei within a “sea” of delocalized electrons. The atoms within such a metallic solid are held together by a unique force known as metallic bonding that gives rise to many useful and varied bulk properties.
All metallic solids exhibit high thermal and electrical conductivity, metallic luster, and malleability....
All metallic solids exhibit high thermal and electrical conductivity, metallic luster, and malleability....
20.8K
Metal-Ligand Bonds
24.4K
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...
24.4K
Gas Exchange and Transport
77.0K
Gas exchange, the intake of molecular oxygen (O2) from the environment and the outflow of carbon dioxide (CO2) into the environment, is necessary for cellular function. Gas exchange during respiration occurs largely via the movement of gas molecules along pressure gradients. Gas travels from areas of higher partial pressure to areas of lower partial pressure. In mammals, gas exchange occurs in the alveoli of the lungs, which are adjacent to capillaries and share a membrane with them.
77.0K
Bonding in Metals
52.5K
Metallic bonds are formed between two metal atoms. A simplified model to describe metallic bonding has been developed by Paul Drüde called the “Electron Sea Model”.
52.5K
Properties of Transition Metals
29.9K
Transition metals are defined as those elements that have partially filled d orbitals. As shown in Figure 1, the d-block elements in groups 3–12 are transition elements. The f-block elements, also called inner transition metals (the lanthanides and actinides), also meet this criterion because the d orbital is partially occupied before the f orbitals.
29.9K
