ディアリレチンを含有するサイクロメタラチウムプラチナ ((II) 複合体:金属調整と合理的なリガンド設計による調節可能なフォトクロミズム
Jacky Chi-Hung Chan1, Wai Han Lam, Hok-Lai Wong
1Institute of Molecular Functional Materials, The University of Hong Kong, Pokfulam Road, Hong Kong, PR China.
Journal of the American Chemical Society
|July 26, 2011
まとめ
新規のプラチナ (プラチナII) コンプレックスには,光染色型ディチエニレチンリガンドが含まれており,光に曝露すると,可逆的な色変化を呈する. 彼らの性質は,リガンド設計と補助リガンドによって調節可能であり,高度な光反応性材料の可能性を秘めています.
科学分野:
- 有機金属化学 有機金属化学
- 材料科学 材料科学とは
- フォトケミストリー フォトケミストリー
背景:
- サイクロメタル化プラチナ ((II) 複合体は,そのユニークな光物理学的性質のために研究されています.
- 光照射で可逆的な色変化を経験する光染色材料は,著しい関心を持っています.
- ディチエニレチン (DTE) ユニットは,効率的な光染色特性で知られています.
研究 の 目的:
- 光染色型ディチエニレチンリガンドを含むサイクロメタル化プラチナ (((II)) 複合物の新シリーズを合成し,特徴づけること.
- これらの新しい複合体の電気化学的,光物理的,光色学的性質を調査する.
- 観察された性質に対するリガンド構造と補助リガンドの影響を調査する.
主な方法:
- サイクロメタラートプラチナ (((II) コンプレックスとC ((() NとO ((() Oリガンドの合成.
- 構造的決定のためのX線結晶学.
- 電気化学分析 (サイクル電圧計) で,酸化還元特性とLUMOレベルを研究する.
- 光化学を評価するために,光物理学的測定 (吸収,放射) を行う.
- フォトエキシテーションと熱漂白運動学によるフォトクロミック行動の研究.
- 理論的な洞察のための密度関数理論 (DFT) 計算.
主要な成果:
- 新しいプラチナ (((II) 複合体 [Pt (((C (() N) (((O (() O)) ]の合成と特徴付けに成功しました.
- 電気化学の研究では,最も低い空の分子軌道 (LUMO) が補助的なOOリガンドに敏感であることが示されました.
- 複合体は,可逆光色素性を示し,光刺激で色彩が大きく変化した.
- フォトクロミックな振る舞いは,ピリジル環の置換物,C() Nリガンドのπ結合,および補助リガンドの影響を受けた.
- 代表的な複合体の熱サイクル逆転のための熱漂白運動と活性化バリアを決定した.
- DFT計算は,観察された性質についての洞察を提供しました.
結論:
- 新しいサイクロメタラ化プラチナ (((II) 複合体は,調節可能な光色反応を示しています.
- DTEユニットおよび補助リガンドを含むリガンドの設計は,光反応性特性を制御する上で重要な役割を果たします.
- これらの発見は,プラチナ複合体に基づく高度な光色材料の開発に寄与しています.
さらに関連する動画
![Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F60786.jpg&w=3840&q=50)
関連する概念動画
03:02Colors and Magnetism
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 eye.
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 eye.
02:51Metal-Ligand Bonds
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...
01:19Complexation Equilibria: The Chelate Effect
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...
02:52Stereoisomerism
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...
00:43Complexometric Titration: Ligands
Different monodentate and polydentate ligands are used as complexing agents in complexometric titration reactions. The formation of complexes by mono- and bidentate ligands involves two or more intermediate steps, limiting their use as complexing agents. In comparison, polydentate ligands can form complexes with metal ions in a single-step process, facilitating sharper end points. This means polydentate ligands, such as amino carboxylic acid derivatives, are most commonly employed in...
01:26Photochemical Electrocyclic Reactions: Stereochemistry
The absorption of UV–visible light by conjugated systems causes the promotion of an electron from the ground state to the excited state. Consequently, photochemical electrocyclic reactions proceed via the excited-state HOMO rather than the ground-state HOMO. Since the ground- and excited-state HOMOs have different symmetries, the stereochemical outcome of electrocyclic reactions depends on the mode of activation; i.e., thermal or photochemical.
Selection Rules: Photochemical Activation
Selection Rules: Photochemical Activation