相关实验视频
Updated: Jun 14, 2025
15:04
Picometer-Precision Atomic Position Tracking through Electron Microscopy
Published on: July 3, 2021
7.3K
一个简短的笔记,关于使用不可减小的表征倾斜的八面体在perovskites
1Clarendon Laboratory, University of Oxford, Parks Road, Oxford, Oxfordshire OX1 3PU, United Kingdom.
概括
单元细胞起源选择影响矿八面体倾斜表示. 建议将原点放置在B-位,而不是A位点,以便进行准确的分析.
科学领域:
- 晶体学 晶体学是指结晶学.
- 材料科学 材料科学 材料科学
- 固态化学 固态化学
背景情况:
- 八面体倾斜对于矿的结构和性质至关重要.
- 单元细胞起源的选择可以影响对称性分析.
- 现有的文献往往忽视了起源选择对倾斜表示的影响.
研究的目的:
- 要突出单元细胞起源选择在确定矿八面体倾斜对称性中的关键作用.
- 推一个标准化和首选的原产地进行一致的分析.
主要方法:
- 矿结构的对称性分析.
- 研究与八面体倾斜相关的不可减少的表示.
- 基于不同单元细胞来源选择的结果的比较.
主要成果:
- 八面体倾斜的不可减少的表示取决于单元细胞起源.
- 不同的起源选择导致不同的对称性赋值.
- B-位起源提供了一个更一致和推的框架.
结论:
- 对矿的精确晶体分析需要仔细考虑单元细胞起源.
- 在B-位的起源标准化将提高矿对称性研究的可靠性和可比性.
相关概念视频
01:34Woodward–Hoffmann Selection Rules and Microscopic Reversibility
3.0K
Electrocyclic reactions, cycloadditions, and sigmatropic rearrangements are concerted pericyclic reactions that proceed via a cyclic transition state. These reactions are stereospecific and regioselective. The stereochemistry of the products depends on the symmetry characteristics of the interacting orbitals and the reaction conditions. Accordingly, pericyclic reactions are classified as either symmetry-allowed or symmetry-forbidden. Woodward and Hoffmann presented the selection criteria for...
3.0K
02:46Crystal Field Theory - Tetrahedral and Square Planar Complexes
41.8K
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,...
41.8K
02:58Crystal Field Theory - Octahedral Complexes
26.2K
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...
26.2K
02:52VSEPR Theory and the Basic Shapes
67.7K
Overview of VSEPR Theory
67.7K
02:27Predicting Molecular Geometry
34.1K
VSEPR Theory for Determination of Electron Pair Geometries
34.1K
02:52Stereoisomerism
11.8K
Isomerism in Complexes
Isomers are different chemical species that have the same chemical formula.
Transition metal complexes often exist as geometric isomers, in which the same atoms are connected through the same types of bonds but with differences in their orientation in space. Coordination complexes with two different ligands in the cis and trans positions from a ligand of interest form isomers. For example, the octahedral [Co(NH3)4Cl2]+ ion has two isomers (Figure 1) In the cis...
Isomers are different chemical species that have the same chemical formula.
Transition metal complexes often exist as geometric isomers, in which the same atoms are connected through the same types of bonds but with differences in their orientation in space. Coordination complexes with two different ligands in the cis and trans positions from a ligand of interest form isomers. For example, the octahedral [Co(NH3)4Cl2]+ ion has two isomers (Figure 1) In the cis...
11.8K