三角プリズマ型単核コバルト (II) 複合体 単分子磁石の振る舞いを示す
Valentin V Novikov1, Alexander A Pavlov1, Yulia V Nelyubina1
1†Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Moscow 119991, Russia.
Journal of the American Chemical Society
|July 23, 2015
まとめ
研究者は,単一分子磁石の振る舞いを示す新しいコバルト (II) 複合体を開発しました. この分子は 記録的に高い リラックス・バリアを備えており 先進的な磁気材料への道を切り開いています
科学分野:
- 協調化学
- 材料科学
- マグネティズム
背景:
- 単分子磁石 (SMM) は量子コンピューティングとデータストレージの進歩に不可欠です
- 単核SMMで高磁性アニソトロピーを達成するには,しばしば複雑な分子幾何学が必要です.
- コバルト (II) 複合体は,その電子特性により,SMMの有望な候補である.
研究 の 目的:
- 三角形のプリズマ幾何学を持つ新しいコバルト (II) 複合体を合成し,特徴づけること.
- 合成された複合体の磁気特性と単一分子磁石の振る舞いを調査する.
- コバルトベースの単核SMMにおけるリラクゼーションバリアの新たな基準を確立する.
主な方法:
- マクロサイクリックリガンドを用いたコバルト (II) ケージ複合体の合成.
- 単一結晶のX線微分法で構造を決定する.
- オーバック・リラクゼーション・バリアを決定するための磁気感受性測定とリラクゼーション・ダイナミクス研究.
主要な成果:
- 三角プリズマ座標幾何学を持つコバルト (II) 複合体が成功して合成されました.
- 複合体は,152 cm ((-1) の高いオーバック・リラクゼーション・バリアを持つ単一分子磁石の振る舞いを表している.
- これは,コバルトベースの単核SMMでこれまでに報告された最大の緩解障壁を表しています.
結論:
- コバルト (II) の複合体における三角形のプリズマ調整は,例外的な磁性アニソトロピーにつながる.
- 報告されたSMMは,優れた安定性と磁気特性を高めるためのさらなる機能化の可能性を示しています.
- この研究は,高性能分子磁気材料の設計に新しい道を開きます.
関連する概念動画
03:02Colors and Magnetism
14.7K
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...
14.7K
02:42Valence Bond Theory
11.7K
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...
11.7K
02:58Crystal Field Theory - Octahedral Complexes
31.9K
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...
31.9K
01:31Ferromagnetism
3.6K
Materials like iron, nickel, and cobalt consist of magnetic domains, within which the magnetic dipoles are arranged parallel to each other. The magnetic dipoles are rigidly aligned in the same direction within a domain by quantum mechanical coupling among the atoms. This coupling is so strong that even thermal agitation at room temperature cannot break it. The result is that each domain has a net dipole moment. However, some materials have weaker coupling, and are ferromagnetic at lower...
3.6K
02:51Metal-Ligand Bonds
25.6K
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...
25.6K
02:34Structural Isomerism
22.5K
Isomerism in Complexes
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly, SCN− can...
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly, SCN− can...
22.5K