Related Experiment Video
Updated: Dec 29, 2025
05:26
Synthesis of Single-Crystalline Core-Shell Metal-Organic Frameworks
Published on: February 10, 2023
3.6K
Tuning Metal-Organic Framework Nanocrystal Shape through Facet-Dependent Coordination
Xiao-Yuan Liu1, Wei-Shang Lo1, Chunhui Wu2
1Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467, United States.
Nano Letters
|January 30, 2020
Summary
Researchers explored how surfactants bind to shaped metal-organic framework (MOF) nanocrystals. They found that controlling crystal facets influences surfactant adsorption, enabling tailored MOF synthesis.
Area of Science:
- Materials Science
- Nanotechnology
- Chemical Engineering
Background:
- Shaped metal-organic framework (MOF) nanocrystals offer tunable properties but controlling their synthesis remains challenging.
- Surfactant binding to MOF surfaces plays a critical role in directing crystal growth and morphology.
- Understanding facet-dependent interactions is key to designing MOF nanocrystals with specific shapes and functions.
Purpose of the Study:
- To investigate the coordination-dependent surfactant binding on different facets of MOF nanocrystals.
- To establish design principles for synthesizing shaped MOF nanocrystals with controlled facet ratios.
- To elucidate the mechanism of growth termination and reinitiation based on surface facet composition.
Main Methods:
- Utilized ZIF-8 as a model MOF system for studying surfactant adsorption.
- Employed infrared (IR) spectroscopy to analyze the coordination environment of Zn nodes.
- Performed molecular dynamics (MD) simulations to understand facet-specific interactions.
- Controlled the ratio of {100} and {110} facets during nanocrystal synthesis.
Main Results:
- Identified distinct coordination environments for Zn nodes on {100} and {110} facets of ZIF-8.
- Demonstrated that different coordination environments lead to varied adsorption of cetyltrimethylammonium bromide (CTAB).
- Showed that growth along {100} facets terminates when MOF nanocrystals are enclosed by {110} facets due to lack of CTAB adsorption.
- Reinitiated MOF growth by etching to create undercoordinated sites.
Conclusions:
- The study provides the first systematic investigation into the design principles for synthesizing shaped MOF nanocrystals.
- Facet-dependent surfactant binding is a crucial factor in controlling MOF nanocrystal morphology.
- Tailoring facet ratios and employing etching strategies can precisely control MOF nanocrystal growth and structure.
Related Concept Videos
02:58Crystal Field Theory - Octahedral Complexes
30.2K
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...
30.2K
02:57Coordination Number and Geometry
18.5K
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.
18.5K
02:42Valence Bond Theory
10.9K
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...
10.9K
02:42Ionic Crystal Structures
16.6K
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...
16.6K
02:46Crystal Field Theory - Tetrahedral and Square Planar Complexes
47.6K
Tetrahedral Complexes
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
47.6K
02:51Metal-Ligand Bonds
23.6K
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...
23.6K