Related Experiment Video
Updated: Jun 28, 2026
05:26
Synthesis of Single-Crystalline Core-Shell Metal-Organic Frameworks
Published on: February 10, 2023
Simple cubic super crystals containing PbTe nanocubes and their core-shell building blocks.
Jun Zhang1, Amar Kumbhar, Jibao He
1Department of Chemistry, State University of New York at Binghamton, Binghamton, New York 13902, USA.
Journal of the American Chemical Society
|October 22, 2008
Summary
Researchers prepared high-quality lead telluride (PbTe) nanocrystals and assembled them into 2D and 3D supercrystals. The study investigated oleylamine
Area of Science:
- Materials Science
- Nanotechnology
- Solid State Chemistry
Background:
- Lead telluride (PbTe) nanocrystals are crucial for advanced material applications.
- Controlling nanocrystal assembly is key to developing novel material properties.
- Understanding synthesis parameters, like the role of oleylamine, is vital for reproducible results.
Purpose of the Study:
- To synthesize high-quality cubic lead telluride (PbTe) nanocrystals.
- To investigate the influence of oleylamine on nanocrystal synthesis and core-shell formation.
- To assemble PbTe nanocrystals into ordered two-dimensional (2D) and three-dimensional (3D) supercrystals.
Main Methods:
- Nanocrystal synthesis and characterization.
- Study of oleylamine's role in synthesis and anion-exchange-mediated core-shell formation.
- Assembly into 2D square arrays and 3D simple cubic supercrystals.
- Analysis using Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), X-ray Diffraction (XRD), Small-Angle X-ray Scattering (SAXS), and Fourier-Transform Infrared Spectroscopy (FTIR).
Main Results:
- Successful preparation of high-quality cubic PbTe nanocrystals.
- Demonstration of PbTe nanocrystal assembly into ordered 2D and 3D supercrystals.
- Characterization of PbTe nanocubes and core-shell structures within these assemblies.
- Insights into oleylamine's function during synthesis and core-shell development.
Conclusions:
- High-quality cubic PbTe nanocrystals can be synthesized and assembled into ordered supercrystals.
- The findings provide a foundation for engineering complex materials with emergent properties.
- Supercrystals composed of cubic building blocks offer pathways to novel material functionalities.
Related Concept Videos
02:42Ionic Crystal Structures
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...
02:37Metallic Solids
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. Many...
All metallic solids exhibit high thermal and electrical conductivity, metallic luster, and malleability. Many...
01:18Unit Cells
A crystal's internal structure is an orderly array of atoms, ions, or molecules, and the details of this array significantly influence the solid's properties. In a crystal, periodically repeating 'structural motifs' - which could be atoms, molecules, or groups thereof - create a 'space lattice.' This is essentially a three-dimensional, infinite array of points, each surrounded by its neighbors in an identical way, forming the basic structure of the crystal.A 'unit cell' is a theoretical...
02:46Crystal Field Theory - Tetrahedral and Square Planar Complexes
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,...
02:58Crystal Field Theory - Octahedral Complexes
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...
02:33Lattice Centering and Coordination Number
The structure of a crystalline solid, whether a metal or not, is best described by considering its simplest repeating unit, which is referred to as its unit cell. The unit cell consists of lattice points that represent the locations of atoms or ions. The entire structure then consists of this unit cell repeating in three dimensions. The three different types of unit cells present in the cubic lattice are illustrated in Figure 1.
Types of Unit Cells
Imagine taking a large number of identical...
Types of Unit Cells
Imagine taking a large number of identical...