関連する実験動画
Updated: Mar 3, 2026
05:26
Synthesis of Single-Crystalline Core-Shell Metal-Organic Frameworks
Published on: February 10, 2023
3.9K
ポーラスのウラン・オーガニック・クリスタルの上部構造のボトムアップ構造
Peng Li1, Nicolaas A Vermeulen1, Christos D Malliakas1
1Department of Chemistry, Northwestern University, Evanston, IL 60208, USA.
Science (New York, N.Y.)
|April 22, 2017
まとめ
化学者はシンプルな部品を使って 複雑なウラン基金属有機フレームワーク (MOF) を生み出した. この画期的な発見により 史上最大の単体細胞と 最低密度MOFが作られ 複雑な構造が示されました
科学分野:
- 材料科学
- 化学について
- ナノテクノロジー
背景:
- 基本的な構成要素から 複雑な化学構造を ボトムアップで構築することは 重要な科学的な課題です
- メタル・オーガニック・フレームワーク (MOF) は調節可能な特性を有しますが,高い構造的複雑性を達成することは困難です.
研究 の 目的:
- 構造的に複雑なメソポラスウラン基金属有機フレームワーク (MOF) の合成を報告する.
- この新しいMOFの前例のない構造的複雑さと結果の性質を特徴づける.
主な方法:
- シンプルなスタートコンポーネントを使って
- 単位細胞の寸法と原子の配置を決定する結晶分析.
- 毛細さと密度の特徴
主要な成果:
- ウラン基のMOFで173.3アングストロムの立方単位細胞で,非生物学的物質としては最大です.
- 構造には10のユニークなウランノードと7つのユニークなトリカルボキシラートリガンドがあり,複雑な四面体とダイヤモンドのトポロジーに編成されています.
- 巨大な穴の形成 (5.0 nmと6.2 nmの内部直径) が,これまでで最も低密度のMOFにつながった.
結論:
- この成功した合成は,MOFの構築で達成可能な新しいレベルの複雑さを示しています.
- この研究は,特異な性質を持つ高度な多孔性材料の設計の可能性を広げています.
- その結果,超低密度MOFは,高表面積と低質量を必要とする領域で潜在的な応用があります.
関連する概念動画
02:58Crystal Field Theory - Octahedral Complexes
31.3K
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...
31.3K
02:46Crystal Field Theory - Tetrahedral and Square Planar Complexes
49.2K
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,...
49.2K
02:22Structures of Solids
19.8K
Solids in which the atoms, ions, or molecules are arranged in a definite repeating pattern are known as crystalline solids. Metals and ionic compounds typically form ordered, crystalline solids. A crystalline solid has a precise melting temperature because each atom or molecule of the same type is held in place with the same forces or energy. Amorphous solids or non-crystalline solids (or, sometimes, glasses) which lack an ordered internal structure and are randomly arranged. Substances that...
19.8K
02:42Ionic Crystal Structures
19.1K
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...
19.1K
01:18Unit Cells
31
A crystal's internal structure is an orderly array of atoms, ions, or molecules, and the details of this array significantly influence the solid's properties. In a crystal, periodically repeating 'structural motifs' - which could be atoms, molecules, or groups thereof - create a 'space lattice.' This is essentially a three-dimensional, infinite array of points, each surrounded by its neighbors in an identical way, forming the basic structure of the crystal.A 'unit cell' is a theoretical...
31