キュービックボックス対球形カプセル,欠陥と無傷の五角形単位から構築された
Fatma Bannani1, Sébastien Floquet, Nathalie Leclerc-Laronze
1Institut Lavoisier de Versailles UMR 8180, Université de Versailles Saint-Quentin, 78035 Versailles, France.
Journal of the American Chemical Society
|November 10, 2012
まとめ
研究者らは,ナノスケールアニオン立方体,つまり大きな内部空洞を持つ高核性ポリオキシオチオモリブデートを合成した. このユニークな {Mo(84) } 型の立方体の構造は,露出したアセテートリガンドにより,高度に機能可能である.
科学分野:
- 無機化学 無機化学とは
- マテリアルサイエンス 材料科学
- ナノテクノロジー ナノテクノロジー
背景:
- ポリオキソチオモリブデートは,多様な構造と性質を持つ複雑な無機群である.
- 高核性クラスターは,新しい分子構造を設計するためのユニークな機会を提供します.
- これらの材料の構造-特性関係を理解することは,それらのアプリケーションにとって極めて重要です.
研究 の 目的:
- 高核性ポリオキソチオモリブデートを新型に合成し,特徴づけること.
- 新しい化合物の固体構造と性質を調査する.
- 合成された分子システムの潜在的機能性を探求する.
主な方法:
- 構造的決定のための単結晶X線結晶学.
- (1) H NMR,IR,Raman,UV-VISスペクトロスコピーを含むスペクトロスコピーの特徴づけ.
- 水晶構造の分析により,空洞やアクセス可能な場所などの重要な特徴を特定します.
主要な成果:
- 高核性ポリオキソチオモリブド酸塩 [H(8) Mo(84) S(48) O(188) H(2) O) ((12) CH(3) COO) ((24) ] ((32-) の製造と特徴付けに成功しました.
- 前例のないナノスケールアニオンの立方体構造 ({Mo(84)}型) の発見.
- 大きな内部空洞の特定 (約. 9 Å 直径) は6つの正方形面と24の交換可能なアセテートリガンドを通してアクセス可能であり,高い機能性を示しています.
結論:
- 合成された {Mo(84) } 型ポリオキシオチオモリブデートは,ユニークな立方体の構造を持つ新しい分子構造を表しています.
- オープンなフレームワークとアクセシブルな空白は,ホスト・ゲスト化学やカタリシスなどの分野での潜在的な応用を示唆しています.
- 交換可能なアセテートリガンドの存在は,この分子システムをさらなる機能化と材料設計のための有望なプラットフォームにします.
関連する概念動画
02:42Ionic Crystal Structures
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...
02:33Lattice Centering and Coordination Number
The structure of a crystalline solid, whether a metal or not, is best described by considering its simplest repeating unit, which is referred to as its unit cell. The unit cell consists of lattice points that represent the locations of atoms or ions. The entire structure then consists of this unit cell repeating in three dimensions. The three different types of unit cells present in the cubic lattice are illustrated in Figure 1.
Types of Unit Cells
Imagine taking a large number of identical...
Types of Unit Cells
Imagine taking a large number of identical...
02:22Structures of Solids
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...
01:24The Seven Crystal Systems: Overview
Crystals with various point group symmetries belong to different crystal classes, which are synonymous terms. Despite being in the same class, crystals may have distinct shapes, like cubes and octahedra. There are 32 three-dimensional point groups, all of which are systematically divided into seven crystal systems.The basic cubic crystal system, exemplified by NaCl, features orthogonal vectors (α = β = �� = 90°) of equal lengths (a = b = c). When specific requirements are not imposed on the...
01:18Unit Cells
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...
02:46Crystal Field Theory - Tetrahedral and Square Planar Complexes
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,...