Crystalline, Porous Helicene Covalent Organic Frameworks
Qianqian Yan1, Shanshan Tao2, Ruoyang Liu2
1School of Chemistry and Chemical Engineering, Hainan University, Haikou, 570228, China.
Angewandte Chemie (International Ed. in English)
|November 29, 2023
Summary
Researchers created novel helicene covalent organic frameworks (COFs) using [7]Helicene. These chiral helical materials exhibit tunable electronic properties and offer potential for advanced applications.
Area of Science:
- Materials Science
- Organic Chemistry
- Supramolecular Chemistry
Background:
- Helicenes are chiral helical molecules with unique conjugated and twisted structures.
- Past research focused on synthesizing helicenes with more rings and complex heterostructures.
- Research on helicene-based materials, including inorganic, organic, and polymeric forms, remains limited.
Purpose of the Study:
- To report the first examples of helicene covalent organic frameworks (COFs).
- To explore the synthesis and properties of these novel COF materials.
- To demonstrate the potential of helicene-based COFs in various applications.
Main Methods:
- Synthesis of [7]Helicene sp² c-COF-1 via condensation of [7]Helicene dialdehyde with trimethyl triazine.
- Utilizing C=C bond formation reaction under solvothermal conditions.
- Characterization using X-ray diffraction to confirm structure and ordering.
Main Results:
- Successfully synthesized [7]Helicene sp² c-COF-1, a novel helicene covalent organic framework.
- The COF exhibits a highly ordered 2D lattice structure due to the twisted [7]Helicene units.
- The material displays extended π conjugation, leading to tunable absorption, emission, redox activity, photoconductivity, and light-emitting properties.
Conclusions:
- This work introduces a new family of covalent organic frameworks based on helicene units.
- The developed helicene COFs possess rich multifunctionalities and significant potential for diverse applications.
- This research opens avenues for exploring unprecedented π architectures and properties in materials science.
Related Concept Videos
02:58Crystal Field Theory - Octahedral Complexes
26.6K
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...
26.6K
02:46Crystal Field Theory - Tetrahedral and Square Planar Complexes
42.7K
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,...
42.7K
02:18Network Covalent Solids
13.5K
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...
13.5K
02:42Ionic Crystal Structures
14.4K
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...
14.4K
01:21Polymer Classification: Crystallinity
2.9K
Unlike ionic or small covalent molecules, polymers do not form crystalline solids due to the diffusion limitations of their long-chain structures. However, polymers contain microscopic crystalline domains separated by amorphous domains.
Crystalline domains are the regions where polymer chains are aligned in an orderly manner and held together in proximity by intermolecular forces. For example, chains in the crystalline domains of polyethylene and nylon are bound together by van der Waals...
Crystalline domains are the regions where polymer chains are aligned in an orderly manner and held together in proximity by intermolecular forces. For example, chains in the crystalline domains of polyethylene and nylon are bound together by van der Waals...
2.9K
01:12Carbon Skeletons
107.7K
Life on Earth is carbon-based, as all macromolecules that make up living organisms contain carbon atoms. All organic compounds have a carbon backbone. Each carbon atom is tetravalent and can bond with four other atoms, making it an extraordinarily flexible component of biological molecules. Because carbon’s valence electrons are stable, it rarely becomes an ion. As the carbon chain increases in length, structural modifications such as ring structures, double bonds, and branching side...
107.7K