Video Experimental Relacionado
Updated: Sep 27, 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
Cuadros orgánicos covalentes reconstruidos
Weiwei Zhang1, Linjiang Chen1,2, Sheng Dai1
1Key Laboratory for Advanced Materials and Institute of Fine Chemicals, Joint International Research Laboratory of Precision Chemistry and Molecular Engineering, Feringa Nobel Prize Scientist Joint Research Center, Frontiers Science Center for Materiobiology and Dynamic Chemistry, School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai, China.
Nature
|April 7, 2022
Resumen
Los investigadores desarrollaron un nuevo método para crear marcos orgánicos covalentes altamente cristalinos (COF) utilizando la reconstrucción del marco. Esta técnica mejora la estabilidad y la porosidad de los COF, mejorando su rendimiento en aplicaciones como la fotocatálisis.
Área de la Ciencia:
- Ciencias de los materiales
- Química orgánica
- Nanotecnología
Sus antecedentes:
- Los marcos orgánicos covalentes (COF) ofrecen propiedades ajustables, pero lograr una alta cristalinidad y estabilidad es un desafío debido a la escasa reversibilidad en las reacciones de formación de marcos.
- Los métodos existentes que utilizan la química reversible a menudo dan lugar a COF con estabilidad comprometida y aplicaciones limitadas.
- Los FOC robustos y altamente cristalinos son deseables para aplicaciones avanzadas, especialmente en catálisis y conversión de energía.
Objetivo del estudio:
- Desarrollar un protocolo general y escalable para la síntesis de COFs de imina robustos y altamente cristalinos.
- Investigar una nueva estrategia de reconstrucción del marco para mejorar las propiedades del COF.
- Demostrar el rendimiento mejorado de los FOC reconstruidos en aplicaciones fotocatalíticas.
Principales métodos:
- Un nuevo protocolo de síntesis que incluye la preorganización de monómeros utilizando ataduras covalentes reversibles.
- Polimerización confinada después de la preorganización del monómero para lograr la reconstrucción del marco.
- Procedimiento sintético sin vacío para la preparación de COF.
Principales resultados:
- Se han preparado con éxito FOC de imina robusta y de alta cristalinidad a través de una vía de reconstrucción de marco.
- Se obtiene un aumento significativo de la cristalinidad y la porosidad en los FOC reconstruidos en comparación con los métodos estándar.
- Se ha demostrado una mejora del transporte del portador de carga en los COF reconstruidos, lo que lleva a altas tasas de evolución de hidrógeno fotocatalítico (hasta 27,98 mmol h−1 g−1).
Conclusiones:
- La estrategia de reconstrucción asistida por nanoconfinamiento proporciona un método general y escalable para producir COF de alta calidad.
- La mejora de la cristalinidad y la porosidad de los COF reconstruidos conduce a un rendimiento superior en la evolución del hidrógeno fotocatalítico.
- Este enfoque representa un paso importante hacia el control preciso de la estructura y la función del material orgánico.
Videos de Conceptos Relacionados
02:58Crystal Field Theory - Octahedral Complexes
28.1K
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...
28.1K
03:02Organic Compounds
53.9K
All living things are formed mostly of carbon compounds called organic compounds. The category of organic compounds includes both natural and synthetic compounds that contain carbon. Although a single, precise definition has yet to be identified by the chemistry community, most agree that a defining trait of organic molecules is the presence of carbon as the principal element, bonded to hydrogen and other carbon atoms. However, some carbon-containing compounds such as carbonates, cyanides, and...
53.9K
02:18Network Covalent Solids
14.8K
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...
14.8K
02:00Molecular Models
41.1K
Physical models representing molecular architectures of chemical compounds play essential roles in understanding chemistry. The use of molecular models makes it easier to visualize the structures and shapes of atoms and molecules.
41.1K
02:17What is Organic Chemistry?
81.5K
Organic chemistry is the study of compounds of carbon called organic compounds. Organic compounds either originate from living organisms or are synthesized by chemists. A defining trait of these compounds is the presence of carbon as the principal element, which is bonded to other carbon atoms and other elements such as hydrogen, oxygen, nitrogen, and sulfur. The existence of a wide array of organic molecules is a consequence of carbon atoms’ ability to form up to four strong bonds to...
81.5K
02:46Crystal Field Theory - Tetrahedral and Square Planar Complexes
45.0K
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,...
45.0K