鉛ハリドペロブスキートおよび他の金属ハリド複合体は,コロイドナノ結晶の無機キャッピングリガンドとして使用されます
Dmitry N Dirin1, Sébastien Dreyfuss, Maryna I Bodnarchuk
1Institute of Inorganic Chemistry, Department of Chemistry and Applied Bioscience, ETH Zürich , CH-8093 Zürich, Switzerland.
Journal of the American Chemical Society
|April 22, 2014
まとめ
この研究は,鉛ハリドペロブスキートなどの無機キャピングリガンドが,半導体ナノ結晶の光学特性と安定性を高めることを示しています. 成功するリガンド交換には,照明量子効率を向上させるための注意深い溶媒選択が必要です.
科学分野:
- 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
- 固体化学 固体化学
背景:
- コロイドナノ結晶は,光電子アプリケーションにおいて極めて重要です.
- 表面の受動化は,効率的な光放出のために不可欠です.
- 非有機リガンドは,ナノ結晶の機能化にユニークな特性を提供します.
研究 の 目的:
- 半導体ナノ結晶のための無機キャッピングリガンドとして金属ハリド複合体の使用を調査する.
- ナノ結晶の光学特性とコロイドの安定性に対するリガンド交換の影響を調査する.
- 機能化されたナノ結晶で高発光量子効率を達成するために.
主な方法:
- IV-VI,II-VI,III-Vの半導体ナノ結晶の表面機能化は,リガンド交換反応によって行われます.
- 最適なリガンド交換のための溶媒特性 (ルイス酸塩基,介電定数) の体系的な研究.
- 機能化されたナノ結晶の光学特性とコロイド安定性の特徴.
主要な成果:
- 鉛ハリドペロブスキート (CH3NH3PbX3) および他の金属ハリド複合体を使用して達成されたリガンド交換の成功.
- 溶媒特性が,リガンド交換とコロイドの安定性を成功させる上で果たす重要な役割を実証した.
- 高い発光量子効率を達成:CH3NH3PbI3機能化されたPbSナノ結晶は20~30%で,CdSe/CdSナノ結晶は50~65%である.
結論:
- 非有機的なキャピングリガンド,特に金属ハリド複合体は,半導体ナノ結晶表面を効果的に受動させない.
- 溶媒特性に対する注意深い制御は,リガンド交換と安定したナノ結晶分散の成功に不可欠です.
- 開発された方法論により,光学特性が大幅に向上し,先進的な光電子装置の道を開くことができる.
関連する概念動画
02:51Metal-Ligand Bonds
19.3K
The hemoglobin in the blood, the chlorophyll in green plants, vitamin B-12, and the catalyst used in the manufacture of polyethylene all contain coordination compounds. Ions of the metals, especially the transition metals, are likely to form complexes.
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
19.3K
02:42Valence Bond Theory
8.9K
Coordination compounds and complexes exhibit different colors, geometries, and magnetic behavior, depending on the metal atom/ion and ligands from which they are composed. In an attempt to explain the bonding and structure of coordination complexes, Linus Pauling proposed the valence bond theory, or VBT, using the concepts of hybridization and the overlapping of the atomic orbitals. According to VBT, the central metal atom or ion (Lewis acid) hybridizes to provide empty orbitals of suitable...
8.9K
01:09Complexation Equilibria: Factors Influencing Stability of Complexes
997
In complexation reactions, metal cations are the electron pair acceptors, and the ligands are the electron pair donors. The stability of the metal complexes depends primarily on the complexing ability of the central metal ion and the nature of the ligands. Generally, the complexing ability of the metal ion depends on the size and charge of the ion. As the metal ion size increases, the stability of the metal complexes decreases, provided that the valency of the metal ion and the ligands remain...
997
00:56Extraction: Advanced Methods
1.3K
Metal ions can be separated from one another by complexation with organic ligands–the chelating agent– to form uncharged chelates. Here, the chelating agent must contain hydrophobic groups and behave as a weak acid, losing a proton to bind with the metal. Since most organic ligands used in this process are insoluble or undergo oxidation in the aqueous phase, the chelating agent is initially added to the organic phase and extracted into the aqueous phase. The metal-ligand complex is...
1.3K
02:58Crystal Field Theory - Octahedral Complexes
28.4K
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...
28.4K
01:19Complexation Equilibria: The Chelate Effect
1.7K
In complexation reactions, metal atoms or cations interact with ligands to form donor-acceptor adducts called metal complexes. Ligands that bind through one donor site are monodentate, ligands with two donor sites are bidentate, and those with more than two donor sites are polydentate ligands. For example, ethylene diamine is a bidentate ligand that binds through two nitrogen donor atoms, forming a five-membered ring. EDTA is a polydentate ligand that binds through four oxygen and two nitrogen...
1.7K