硫酸金属有机框架中的超酸性-808
Juncong Jiang1, Felipe Gándara, Yue-Biao Zhang
1Department of Chemistry, University of California, Berkeley and Kavli Energy NanoSciences Institute at Berkeley , Berkeley, California 94720, United States.
Journal of the American Chemical Society
|August 27, 2014
概括
研究人员使用硫酸金属有机框架 (MOF) 开发了一种新的固体超酸. 这种新的MOF材料具有异常的酸度,为先进的催化应用铺平了道路.
科学领域:
- 材料科学 材料科学 材料科学
- 化学 化学 化学
- 催化剂是一种催化剂.
背景情况:
- 超酸是高度酸性的材料,具有哈梅特酸度函数 (H0) ≤ -12.
- 固态超酸比液态酸具有优势,但需要新的可设计系统.
- 金属有机框架 (MOF) 是具有可调节结构的多功能多孔材料.
研究的目的:
- 为了合成和表征一种基于金属有机框架 (MOF) 的新型固体超酸.
- 研究硫酸MOF作为超酸性材料的潜力.
- 提供MOF结构中超酸度的第一个证据.
主要方法:
- 通过用硫酸处理MOF-808-P,合成硫化金属有机框架 (MOF-808-2.5SO4).
- 使用哈梅特酸度函数 (H0) 描述材料的酸度.
- 使用单晶X射线衍射分析进行结构阐明.
主要成果:
- 硫化MOF,MOF-808-2.5SO4,表现出一个哈梅特酸度函数 (H0) ≤-14.5.5.
- 这种酸度水平证实了该材料是超酸的.
- 单晶X射线衍射确定了与结合的硫酸盐群作为超酸性的来源.
结论:
- 该研究报告了金属有机框架 (MOF) 中超酸度的第一个实例.
- 硫酸MOFs代表了一类新的可指定的固体超酸.
- 这些发现为开发先进的固酸催化剂开辟了道路.
相关概念视频
Acid Strength and Molecular Structure
25.9K
Binary Acids and Bases
In the absence of any leveling effect, the acid strength of binary compounds of hydrogen with nonmetals (A) increases as the H-A bond strength decreases down a group in the periodic table. For group 17, the order of increasing acidity is HF < HCl < HBr < HI. Likewise, for group 16, the order of increasing acid strength is H2O < H2S < H2Se < H2Te. Across a row in the periodic table, the acid strength of binary hydrogen compounds increases with...
In the absence of any leveling effect, the acid strength of binary compounds of hydrogen with nonmetals (A) increases as the H-A bond strength decreases down a group in the periodic table. For group 17, the order of increasing acidity is HF < HCl < HBr < HI. Likewise, for group 16, the order of increasing acid strength is H2O < H2S < H2Se < H2Te. Across a row in the periodic table, the acid strength of binary hydrogen compounds increases with...
25.9K
Crystal Field Theory - Octahedral Complexes
28.4K
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...
28.4K
Ionic Crystal Structures
17.9K
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...
17.9K
Metal-Ligand Bonds
19.2K
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...
19.2K
Formation of Complex Ions
18.8K
A type of Lewis acid-base chemistry involves the formation of a complex ion (or a coordination complex) comprising a central atom, typically a transition metal cation, surrounded by ions or molecules called ligands. These ligands can be neutral molecules like H2O or NH3, or ions such as CN− or OH−. Often, the ligands act as Lewis bases, donating a pair of electrons to the central atom. These types of Lewis acid-base reactions are examples of a broad subdiscipline called coordination...
18.8K
Molecular Structure and Acidity
14.9K
An acid can be deprotonated to form a conjugate base or an anion. If the produced anion is more stable, then the acid is stronger. On the contrary, if the anion is unstable, then the acid is weaker. Hence, to determine the acidity of the compound, the stability of its conjugate base is studied using various factors.
The size effect explains the change in atomic size on acidity. When comparing the acids formed from elements that belong to the same column in the periodic table, their atomic sizes...
The size effect explains the change in atomic size on acidity. When comparing the acids formed from elements that belong to the same column in the periodic table, their atomic sizes...
14.9K


