控制异形金属有机框架复杂形态的因素
Vivek Singh1, Yishay Feldman2, Gregory Leitus2
1Department of Molecular Chemistry and Materials Science, Weizmann Institute of Science, Rehovot, 7610001, Israel.
Chemistry (Weinheim an der Bergstrasse, Germany)
|June 19, 2023
概括
金属子影响晶体形态,形成独特的双层花和六角镜. 协调强度和反应剂比率决定了这些新型材料中的晶体形状和结构.
科学领域:
- 无机化学 无机化学
- 晶体学 晶体学是指结晶学.
- 材料科学 材料科学 材料科学
背景情况:
- 金属酸盐和状有机连接体可以自组装成复杂的晶体结构.
- 选择的金属阴离子显著影响了由此产生的晶体形态和生长模式.
- 了解结构形态关系对于设计新型晶体材料至关重要.
研究的目的:
- 为了研究双价金属酸盐 (Cu,Ni,Co,Mn) 与有机连接体的自组合.
- 探索不同的金属和反应物比如何影响晶体形态和结构.
- 阐明独特的双层花和六角晶体结构形成背后的机制.
主要方法:
- 结晶材料的合成使用金属酸盐和一个Achiral有机连接体.
- 结晶学分析以确定结构和形态特征.
- 不同的金属与配合物比率来观察对晶体形成的影响.
- 微观分析以研究晶体纹理和生长模式.
主要成果:
- 同形六角晶体结构形成了多种不同的形态,包括双层花,六角双金字塔和镜.
- 较强的协调子 (Cu,Ni) 产生了不寻常的,均的晶体形状,而较弱的协调子 (Mn,Co) 产生了规律的六角形状.
- 铜酸盐反应根据反应物比率显示出不同的形态:过多的金属盐导致均的六角晶体,而过多的合物导致双层结构.
- 观察到带有螺旋道的状框架,并发现双层花结晶是同体的.
结论:
- 该研究表明,通过选择金属离子和反应物比率,可以精确控制晶体形态.
- 不寻常的双层花和六角晶体结构被成功合成和特征化.
- 这些发现为控制晶体形成的自我组装机制和协调化学提供了洞察力.
相关概念视频
02:58Crystal Field Theory - Octahedral Complexes
26.9K
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...
26.9K
02:34Structural Isomerism
19.5K
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...
19.5K
02:42Ionic Crystal Structures
14.5K
Ionic crystals consist of two or more different kinds of ions that usually have different sizes. The packing of these ions into a crystal structure is more complex than the packing of metal atoms that are the same size.
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
14.5K
02:57Coordination Number and Geometry
16.2K
For transition metal complexes, the coordination number determines the geometry around the central metal ion. Table 1 compares coordination numbers to molecular geometry. The most common structures of the complexes in coordination compounds are octahedral, tetrahedral, and square planar.
16.2K
01:09Complexation Equilibria: Factors Influencing Stability of Complexes
417
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...
417
02:42Valence Bond Theory
8.8K
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...
8.8K