分子シアンメタラートボックスによるK ((+)) とC ((+)) のレドックススイッチされた複合/解複合
Julie L Boyer1, Maya Ramesh, Haijun Yao
1Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
Journal of the American Chemical Society
|January 31, 2007
まとめ
研究者らはコバルトとロジウム複合体を用いて高対称性分子箱を合成した. これらのケージは,カリウムとセシウムイオンをカプセル化し,カチオン認識とイオン交換のユニークな特性を示しています.
科学分野:
- 協調化化学について
- 超分子化学 超分子化学
- 材料科学 材料科学とは
背景:
- イオン封入のための新しい分子ケージの開発.
- 構造的多様性のための金属シアン化物フレームワークの探査.
- 合成受容体におけるカチオン結合と交換現象の調査.
研究 の 目的:
- コバルトとロジウムに基づいた新しい高対称性分子ボックスを合成し,特徴づけること.
- これらの分子ケージのイオン封じ込めとイオン交換能力を調査する.
- 合成された構造物のリドックス特性とカチオン認識行動を探求する.
主な方法:
- 凝縮反応による分子箱 [KCo(8) ]PF(6) と [KRh(4) Co(4) ]PF(6) の合成.
- 赤外線 (IR) スペクトロスコピー,核磁気共振 (NMR) スペクトロスコピー,および電子スプレーイオン化質量スペクトロメトリ (ESI-MS) を使用して特徴づけました.
- X線結晶学による構造確認.
- 様々なカチオン (Cs+, NH4+) とのイオン交換実験.
- レドックス特性とカチオン認識を調査するための電気化学の研究.
主要な成果:
- カリウムイオンをカプセル化した高対称性分子箱 [KCo(8) ]PF(6) と [KRh(4) Co(4) ]PF(6) の合成に成功しました.
- 結晶学的分析により,オーダーされたシアン化物リガンドを含む分子箱構造が確認されました.
- 定量的イオン交換は,両方のケージでCs+とK+との間で観察されましたが,ラベル付きのケージでのCs+とK+の交換は,断片化をもたらしました.
- NH4+イオン交換は,溶媒に依存した結果を示し,陽子交換によって示された可変性を示した.
- 籠の酸化により,カプセル化されたカチオンが放出され,これは還元によって逆転するプロセスである.
- 電気化学的測定により,K+とCs+との間のカチオン認識の違いが明らかになった.
結論:
- 合成された分子箱は,驚くべき構造的整合性とイオン封じ込め能力を示しています.
- イオン交換特性には,カチオンと溶媒の性質が影響する.
- 檻は,カチオン認識と選択的結合の可能性を示しています.
- レドックス活性により,カチオンの制御された放出と再封じ込みが可能です.
さらに関連する動画
08:34A Dual-Functional Electroactive Filter Towards Simultaneously SbIII Oxidation and Sequestration
Published on: December 5, 2019
4.6K
06:53Author Spotlight: Magnetometric Characterization of Intermediates in the Solid-State Electrochemistry of Redox-Active Metal-Organic Frameworks
Published on: June 9, 2023
2.5K
関連する概念動画
03:45Formation of Complex Ions
18.8K
A type of Lewis acid-base chemistry involves the formation of a complex ion (or a coordination complex) comprising a central atom, typically a transition metal cation, surrounded by ions or molecules called ligands. These ligands can be neutral molecules like H2O or NH3, or ions such as CN− or OH−. Often, the ligands act as Lewis bases, donating a pair of electrons to the central atom. These types of Lewis acid-base reactions are examples of a broad subdiscipline called coordination...
18.8K
03:02Colors and Magnetism
12.1K
Color in Coordination Complexes
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...
12.1K
01:23Complexation Equilibria: Overview
1.6K
Complexation reactions take place when dative or coordinate covalent bonds form between metal ions and ligands. The compounds formed in these reactions are called coordination compounds. The number of bonds formed between the metal ion and the ligands is called its coordination number. Generally, most metal ions in an aqueous solution are solvated by water molecules and thus exist as aqua complexes.
The equilibrium constant of the complexation reaction is represented as the formation constant...
The equilibrium constant of the complexation reaction is represented as the formation constant...
1.6K
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
00:39Complexometric Titration: Overview
10.9K
Complexometric titration involves the formation of a complex by reacting a metal ion with one or more ligands. A visual indicator often detects the end point of a complexometric titration. It is added to the metal solution before the titration, forming a stable metal–indicator complex and imparting color to the solution. As the titration approaches the equivalence point, the excess of the added ligand displaces the indicator from the metal–indicator complex, releasing the free...
10.9K
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