探测电荷转移共晶体中的介电现象的原子行为
Rohit Bhowal1, Anina Anju Balaraman2, Manasi Ghosh3
1Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal Bypass Road, Bhauri, Bhopal 462066, Madhya Pradesh, India.
Journal of the American Chemical Society
|December 30, 2020
概括
新的有机电荷转移 (CT) 共晶体显示基于分子堆叠的调节性介电性质. 这项研究为各种应用提供了设计具有增强介电反应的先进材料的见解.
科学领域:
- 材料科学
- 晶体学
- 固态化学
背景情况:
- 有机电荷转移 (CT) 共同晶体因其电子和光学特性而有趣.
- 了解分子组合和宏观性质之间的关系对于材料设计至关重要.
- 介电性质对于电子设备的应用很重要.
研究的目的:
- 合成和描述新的二进制CT共晶体.
- 研究晶体结构,电荷转移相互作用和介电反应之间的关系.
- 探索设计具有增强介电性能的CT共晶的策略.
主要方法:
- 溶剂滴滴辅助的机械化学研磨用于共晶合成.
- 用X射线结晶学来确定结构.
- 固态13C核磁共振 (NMR) 光谱用于分子动力学分析.
- 在交流电流 (ac) 电场下进行介电光谱.
主要成果:
- 六个新的二元CT共晶成功合成,在研磨过程中呈现颜色变化.
- 晶体结构显示了由π·π相互作用驱动的混合供体-接受体 (D-A-D-A) 堆叠列.
- 观察到不同的介电反应,与CT相互作用的强度和分子动态相关.
- 强大的CT共晶体显示了刚性框架,而较弱的相互作用允许分子放松并有助于介电性质.
- 核磁共振研究证实了共晶体中的原子分子动力学,导致高电容性.
结论:
- CT共晶的介电行为受到分子间相互作用的性质和强度以及由此产生的分子动态的强烈影响.
- 通过结合非中心对称分子的旋转动力学来提高介电性质的设计策略.
- 基于DA的有机CT系统具有混合堆,对材料科学应用具有重大潜力.
更多相关视频
08:54Vibrational Spectra of a N719-Chromophore/Titania Interface from Empirical-Potential Molecular-Dynamics Simulation, Solvated by a Room Temperature Ionic Liquid
Published on: January 25, 2020
5.8K
06:53Author Spotlight: Magnetometric Characterization of Intermediates in the Solid-State Electrochemistry of Redox-Active Metal-Organic Frameworks
Published on: June 9, 2023
2.3K
相关概念视频
02:58Crystal Field Theory - Octahedral Complexes
29.1K
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...
29.1K
02:46Crystal Field Theory - Tetrahedral and Square Planar Complexes
46.4K
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,...
46.4K
02:42Ionic Crystal Structures
16.2K
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...
16.2K
02:54Molecular and Ionic Solids
19.3K
Crystalline solids are divided into four types: molecular, ionic, metallic, and covalent network based on the type of constituent units and their interparticle interactions.
Molecular Solids
Molecular crystalline solids, such as ice, sucrose (table sugar), and iodine, are solids that are composed of neutral molecules as their constituent units. These molecules are held together by weak intermolecular forces such as London dispersion forces, dipole-dipole interactions, or hydrogen bonds, which...
Molecular Solids
Molecular crystalline solids, such as ice, sucrose (table sugar), and iodine, are solids that are composed of neutral molecules as their constituent units. These molecules are held together by weak intermolecular forces such as London dispersion forces, dipole-dipole interactions, or hydrogen bonds, which...
19.3K
02:48Ionic Bonding and Electron Transfer
47.4K
Ions are atoms or molecules bearing an electrical charge. A cation (a positive ion) forms when a neutral atom loses one or more electrons from its valence shell, and an anion (a negative ion) forms when a neutral atom gains one or more electrons in its valence shell. Compounds composed of ions are called ionic compounds (or salts), and their constituent ions are held together by ionic bonds: electrostatic forces of attraction between oppositely charged cations and anions.
47.4K
01:27Electrostatic Boundary Conditions in Dielectrics
1.6K
When an electric field passes from one homogeneous medium to another, crossing the boundary between the two mediums imparts a discontinuity in the electric field. This results in electrostatic boundary conditions that depend on the type of mediums the field propagates through.
Consider a case where both the mediums across a boundary are two different dielectric materials. Recall that the electric field and electric displacement are proportional and related through the material's permittivity....
Consider a case where both the mediums across a boundary are two different dielectric materials. Recall that the electric field and electric displacement are proportional and related through the material's permittivity....
1.6K