Video Experimental Relacionado
Updated: Oct 20, 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
13.6K
Un marco orgánico covalente 3D cúbico con topología nbo
Xue Wang1,2, Mounib Bahri3, Zhiwei Fu2
1Leverhulme Research Centre for Functional Materials Design, University of Liverpool, Liverpool, L7 3NY, U.K.
Journal of the American Chemical Society
|September 13, 2021
Resumen
Los investigadores sintetizaron un nuevo marco orgánico covalente tridimensional poroso (3D COF) utilizando unidades de cobalto ((II) plano cuadrado y enlaces de espiroborato. Este nuevo material, SPB-COF-DBA, exhibe una alta cristalinidad y una superficie significativa.
Área de la Ciencia:
- Ciencias de los materiales
- Química
- Nanotecnología
Sus antecedentes:
- Los marcos orgánicos covalentes tridimensionales (3D) son materiales cruciales con aplicaciones en varios campos.
- Su síntesis a menudo se basa en bloques de construcción de alta conectividad o control preciso de la alineación estructural.
- Lograr topologías de red específicas, como la topología nbo, sigue siendo un desafío sintético.
Objetivo del estudio:
- Desarrollar una nueva estrategia sintética para la construcción de COF 3D con la topología nbo.
- Utilizar unidades de cobalto ((II) ftalaciocianina (PcCo) y enlaces de espiroborato tetraédrico (SPB) para el ensamblaje de la estructura controlada.
- Caracterizar las propiedades estructurales, cristalinas y porosas del COF resultante.
Principales métodos:
- Emplear una estrategia de alineación controlada utilizando unidades PcCo y enlaces SPB.
- Utilizando enlaces SPB para imponer ángulos diédricos de 90 ° entre las unidades PcCo, dirigiendo la formación de la topología nbo.
- Caracterización del material sintetizado (SPB-COF-DBA) mediante difracción de rayos X en polvo (PXRD) y microscopía electrónica de transmisión de alta resolución (HR-TEM).
Principales resultados:
- Síntesis exitosa de un COF 3D poroso, SPB-COF-DBA, con la topología nbo no interpenetrada.
- SPB-COF-DBA exhibe alta cristalinidad y orden de largo alcance, confirmado por 11 picos de difracción resueltos en PXRD.
- Las imágenes de HR-TEM validaron la red cristalina bien ordenada.
- El material posee poros cúbicos y porosidad permanente, con una superficie de Brunauer-Emmett-Teller (BET) de 1726 m2 g-1.
Conclusiones:
- La estrategia de alineación controlada utilizando bloques de construcción específicos es efectiva para la construcción de topologías de COF 3D complejas.
- SPB-COF-DBA representa un nuevo material altamente cristalino y poroso con aplicaciones potenciales en áreas que requieren materiales de gran superficie.
- El estudio demuestra la integración exitosa de las unidades PcCo en un marco 3D robusto con porosidad definida.
Videos de Conceptos Relacionados
02:18Network Covalent Solids
15.1K
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...
15.1K
02:58Crystal Field Theory - Octahedral Complexes
28.5K
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...
28.5K
02:46Crystal Field Theory - Tetrahedral and Square Planar Complexes
45.4K
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,...
45.4K
02:06Newman Projections
18.9K
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...
18.9K
01:18Aromatic Hydrocarbon Anions: Structural Overview
3.1K
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...
3.1K
03:24Hybridization of Atomic Orbitals I
52.7K
The mathematical expression known as the wave function, ψ, contains information about each orbital and the wavelike properties of electrons in an isolated atom. When atoms are bound together in a molecule, the wave functions combine to produce new mathematical descriptions that have different shapes. This process of combining the wave functions for atomic orbitals is called hybridization and is mathematically accomplished by the linear combination of atomic orbitals. The new orbitals that...
52.7K