在离散的化物桥梁复合体[Co (tmphen) ]3[Fe (Fe (CN) ]62]中发生电荷转移诱导的旋转转变
Curtis P Berlinguette1, Alina Dragulescu-Andrasi, Andreas Sieber
1Department of Chemistry, Texas A&M University, College Station, Texas 77842-3012, USA.
Journal of the American Chemical Society
|May 20, 2004
概括
在离散分子复合体中观察到电荷转移诱导的自旋转变 (CTIST). 这项研究详细介绍了在化物桥梁铁集群中的第一个分子级CTIST.
科学领域:
- 协调化学 协调化学
- 材料科学是一种材料科学.
- 旋转交叉现象 旋转交叉现象
背景情况:
- 金属复合体中的旋转过渡对于分子开关和记忆器件至关重要.
- 化物桥接协调化合物为研究磁现象提供了多功能平台.
研究的目的:
- 在离散分子系统中研究电荷转移诱导的自旋转变 (CTIST).
- 描述一个新的五核 - 铁化物桥梁复合体.
主要方法:
- 单晶X射线衍射以确定分子结构.
- 57Fe Mössbauer光谱检测铁的氧化状态和旋转状态.
- 测量磁性易感度以分析温度依赖的磁性行为.
主要成果:
- 观察电荷转移诱导的旋转转变 (CTIST) 在离散复合体{[Co(tmphen) 2}3[Fe(CN) 6}2}.
- 在温度范围内对和铁离子的氧化状态的详细描述.
- 确认五核复合体是第一个表现出CTIST的离散分子系统.
结论:
- 离散的化物桥梁复合体{[Co(tmphen) 2 3[Fe(CN) 6 2}表现出电荷转移诱导的旋转过渡.
- 这项工作为分子级别的旋转过渡研究建立了新的基准.
- 这些发现为设计具有可调节磁性特性的新型分子材料开辟了道路.
更多相关视频
08:55Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses
Published on: June 7, 2018
06:53Magnetometric Characterization of Intermediates in the Solid-State Electrochemistry of Redox-Active Metal-Organic Frameworks
Published on: June 9, 2023
相关概念视频
Structural Isomerism
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 be...
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 be...
Valence Bond Theory
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...
Crystal Field Theory - Octahedral Complexes
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...
Colors 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.
Ferromagnetism
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...
The Electrical Double Layer
In the region where two bulk phases meet, an intricate electric charge distribution arises due to charge transfer, ion adsorption, molecular orientation, and charge distortion. This complex distribution is commonly referred to as the electrical double layer.When a solid electrode interfaces with ions in an electrolyte solution, the speed of electron transfer dictates the rates of oxidation and reduction. The electrode acquires a charge through the escape of atoms into the solution as cations or...
