M4 (M = Ni, Cu) クラスタの強い電子と磁気結合は,低座標メタルセンター間の直接軌道相互作用によるものである
Khetpakorn Chakarawet, Mihail Atanasov1,2, Jonathan Marbey3
1Max-Planck Institut für Kohlenforschung, Mülheim an der Ruhr D-45470, Germany.
Journal of the American Chemical Society
|October 28, 2020
まとめ
この研究では,金属と金属の軌道が直接重複する四核移行金属クラスターを調査し,大きなスピンの基底状態やニッケルと銅の化合物の遅い磁気放緩のようなユニークな電子および磁気特性を明らかにしました.
科学分野:
- 無機化学
- 材料科学
- マグネト化学
背景:
- 低座標の金属中心を持つ四核型移行金属クラスターは,そのユニークな電子および磁気特性のために興味があります.
- 直接的な金属と金属の軌道の重なりは,これらのクラスターの行動に影響を与える重要な特徴です.
- これらの相互作用を理解することは 新しい磁気材料の設計に不可欠です
研究 の 目的:
- テトラ核移行金属クラスター化合物M4 ((NPtBu3) 4) と[M4 ((NPtBu3) 4) ][B ((C6F5) 4) ] (M = Ni, Cu) の電子および磁気特性を調査する.
- 結合相互作用と磁気行動への影響を明らかにする.
- これらのシステムにおける ゆっくりとした磁気放緩の可能性を 探求するためです
主な方法:
- 四核ニッケルと銅のクラスター化合物の合成と特徴付け.
- X線 difraktion,電気化学,磁気,そしてスペクトル分析.
- 関連した電子構造の計算
主要な成果:
- 直接的な軌道の重なりは,大きなスピンの基底状態と,ニッケルクラスターの非局所化,スピン相関電子につながる.
- ニッケルクラスターで観測された鉄磁性基底状態と移動性電子磁性.
- カチオンニッケルクラスターは,有意な磁気アニソトロピーとゼロフィールドの緩やかな磁気放松を示しています.
- 銅のクラスターは,ラマンプロセスを通してゆっくりと磁気放緩を示しています.
結論:
- 低座標の金属クラスターにおける直接的な金属対金属軌道相互作用は,ユニークな電子および磁気特性を生み出します.
- これらのクラスターは,分子磁気とスピントロニックアプリケーションの有望な候補として機能します.
- この発見は,クラスター設計による磁気行動の調整性を強調しています.
さらに関連する動画
![The Synthesis of [Sn10SiSiMe334]2- Using a Metastable SnI Halide Solution Synthesized via a Co-condensation Technique](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F54498.jpg&w=3840&q=50)
関連する概念動画
02:42Valence Bond Theory
10.4K
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...
10.4K
01:27¹H NMR: Long-Range Coupling
2.3K
The coupling interactions of nuclei across four or more bonds are usually weak, with J values less than 1 Hz. While these are usually not observed in spectra, the presence of multiple bonds along the coupling pathway can result in observable long-range coupling.
In alkenes, spin information is communicated via σ–π overlap, as seen in allylic (four-bond) and homoallylic (five-bond) couplings. These coupling interactions are stronger when the σ bond is parallel to the alkene...
In alkenes, spin information is communicated via σ–π overlap, as seen in allylic (four-bond) and homoallylic (five-bond) couplings. These coupling interactions are stronger when the σ bond is parallel to the alkene...
2.3K
03:02Colors and Magnetism
13.2K
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...
13.2K
02:58Crystal Field Theory - Octahedral Complexes
29.5K
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...
29.5K
01:20Spin–Spin Coupling: Two-Bond Coupling (Geminal Coupling)
1.4K
Two NMR-active nuclei bonded to a central atom can be involved in geminal or two-bond coupling. Geminal coupling is commonly seen between diastereotopic protons in chiral molecules and unsymmetrical alkenes, among others.
The central atom need not be NMR-active because its electrons are affected by the electron polarization of the spin-active atoms. However, spin information is transmitted less effectively than in one-bond coupling, and 2J values are usually weaker than 1J values. The energy of...
The central atom need not be NMR-active because its electrons are affected by the electron polarization of the spin-active atoms. However, spin information is transmitted less effectively than in one-bond coupling, and 2J values are usually weaker than 1J values. The energy of...
1.4K
02:51Metal-Ligand Bonds
23.1K
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...
23.1K