Video Experimental Relacionado
Updated: May 29, 2025
08:42
Microfluidic-based Synthesis of Covalent Organic Frameworks COFs: A Tool for Continuous Production of COF Fibers and Direct Printing on a Surface
Published on: July 10, 2017
13.3K
Estructuras orgánicas covalentes tridimensionales con una pequeña topología
Xinyu Wu1, Hanwen Wang1, Ning Huang1
1State Key Laboratory of Silicon and Advanced Semiconductor Materials, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310058, China.
Journal of the American Chemical Society
|February 8, 2025
Resumen
Los investigadores desarrollaron nuevos marcos orgánicos covalentes 3D (COF) con una estructura topológica única. Estos nuevos COF exhiben una constante dieléctrica récord, lo que los hace prometedores para aplicaciones avanzadas de condensadores.
Área de la Ciencia:
- Ciencias de los materiales
- Química
- Nanotecnología
Sus antecedentes:
- Los marcos orgánicos covalentes (COF) ofrecen estructuras y propiedades ajustables.
- El desarrollo de FOC cristalinos 3D con nuevas topologías sigue siendo un desafío importante.
Objetivo del estudio:
- Diseñar y sintetizar nuevos COF 3D con una estructura topológica específica.
- Investigar las propiedades dieléctricas de estos nuevos COF para posibles aplicaciones.
Principales métodos:
- El ensamblaje de COF 3D utilizando bloques de construcción simétricos D4h y C2h.
- Análisis cristalográfico para determinar el grupo espacial Imma y la topología de la red.
- Medición de la constante dieléctrica y de las pérdidas a altas frecuencias (>1 kHz).
Principales resultados:
- Desarrollo exitoso de COFs tridimensionales con la estructura topológica lil.
- Formación de una red no interpenetrada con unidades D4h y C2h.
- Logró una constante dieléctrica récord de 63 con baja pérdida dieléctrica.
Conclusiones:
- El estudio proporciona un plan para el diseño de COFs tridimensionales.
- Los COF sintetizados son materiales prometedores para condensadores de alta densidad energética e impulsados.
Videos de Conceptos Relacionados
02:18Network Covalent Solids
13.3K
Network covalent solids contain a three-dimensional network of covalently bonded atoms as found in the crystal structures of nonmetals like diamond, graphite, silicon, and some covalent compounds, such as silicon dioxide (sand) and silicon carbide (carborundum, the abrasive on sandpaper). Many minerals have networks of covalent bonds.
To break or to melt a covalent network solid, covalent bonds must be broken. Because covalent bonds are relatively strong, covalent network solids are typically...
To break or to melt a covalent network solid, covalent bonds must be broken. Because covalent bonds are relatively strong, covalent network solids are typically...
13.3K
02:46Crystal Field Theory - Tetrahedral and Square Planar Complexes
41.2K
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,...
41.2K
02:37Metallic Solids
18.2K
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....
18.2K
02:58Crystal Field Theory - Octahedral Complexes
26.1K
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...
26.1K
02:06Newman Projections
16.3K
Different notations are used to represent the three-dimensional structure of molecules on two-dimensional surfaces. One of the most commonly used representations is the dash-wedge formula. The dashed wedges, solid wedges, and the plane lines indicate the groups situated behind the plane, coming out of the plane, and in the plane, respectively.
The organic molecules rotate across the single bonds leading to numerous temporary three-dimensional structures of varying energy known as...
The organic molecules rotate across the single bonds leading to numerous temporary three-dimensional structures of varying energy known as...
16.3K
01:18Aromatic Hydrocarbon Anions: Structural Overview
2.6K
Neutral hydrocarbons like cyclopentadiene with an odd number of carbon atoms and one intervening CH2 group in the ring are not aromatic. Cyclopentadiene with 4 π electrons does not satisfy the 4n + 2 π electron rule. Additionally, the intervening CH2 group is sp3 hybridized and lacks a vacant p orbital, thereby interrupting the overlap of p orbitals in a continuous manner and preventing the delocalization of π electrons throughout the ring.
Due to the absence of continuous...
Due to the absence of continuous...
2.6K