相关实验视频
Updated: Jul 5, 2026
08:45
Fabrication of Spatially Confined Complex Oxides
Published on: July 1, 2013
基于Mn4复合体的二维网络,由二胺离子连接在一起:从单分子磁铁到经典磁铁行为
Hitoshi Miyasaka1, Kazuya Nakata, Lollita Lecren
1Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, 1-1 Minamiohsawa, Hachioji, Tokyo 192-0397, Japan. miyasaka@comp.metro-u.ac.jp
Journal of the American Chemical Society
|March 16, 2006
概括
研究人员使用 (Mn) 四核单分子磁铁 (SMM) 合成了新的2D网络化合物,这些磁铁由二胺 (dcn-) 连接在一起. 微调的合成条件允许控制Mn(II) 协调,从而产生不同的磁性特性和先进磁性材料的潜力.
科学领域:
- 协调化学 协调化学
- 材料科学 材料科学 材料科学
- 磁力学 磁力学 是一种
背景情况:
- 单分子磁铁 (SMM) 对于开发高密度数据存储和量子计算至关重要.
- (Mn) 四核集群提供可调节的磁性.
- 二胺 (dcn-) 连接器是构建扩展磁网的多功能构建模块.
研究的目的:
- 为了合成和描述基于Mn (III) /Mn (II) 四核SMM的新型2D网络化合物.
- 研究合成条件对Mn4/dcn-系统的结构和磁性行为的影响.
- 探索结构变化和磁性特性之间的关系,包括SMM行为和远程磁性排序.
主要方法:
- 基于Mn4的化合物的溶热合成与二胺结合剂.
- 单晶X射线衍射用于结构阐明.
- 测量直流电磁感应度的测量.
- 测量热容量. 测量热容量.
- 磁化研究.磁化研究.
主要成果:
- 合成了三种新的2D网络化合物 ([Mn4(hmp) 4 ((Hpdm) 2 ((dcn) 2)) ClO4) 2 x 2 H2O x 2 MeCN (2), [Mn4 ((hmp) 4Br2 ((OMe) 2 ((dcn) 2)) x 0.5 H2O x 2 THF (3), [Mn4 ((hmp) 6 ((dcn) 2)) ClO4) 2 (4)) 这三种化合物.
- 保持了双立方体[Mn4]单元,具有可调节的Mn(II) 协调球体.
- 铁磁内部[Mn4]相互作用导致了S(T) = 9的基本状态.
- 化合物2和1表现出SMM行为,而化合物4显示出远程倾斜的反铁磁顺序.
- 化合物3显示了倾斜的反铁磁顺序和缓慢的磁化放松.
结论:
- Mn4/dcn-系统具有多功能性,可以通过微调合成条件合理设计磁性材料.
- 控制二胺对Mn ((II) 位点的协调是获得离散集群,2D网络或3D化合物的关键.
- 结构变化,特别是[Mn4]单位的方向,显著影响磁性特性,导致从SMM到远程磁性秩序的各种行为.
相关概念视频
02:18Network Covalent Solids
Network covalent solids contain a three-dimensional network of covalently bonded atoms as found in the crystal structures of nonmetals like diamond, graphite, silicon, and some covalent compounds, such as silicon dioxide (sand) and silicon carbide (carborundum, the abrasive on sandpaper). Many minerals have networks of covalent bonds.
To break or to melt a covalent network solid, covalent bonds must be broken. Because covalent bonds are relatively strong, covalent network solids are typically...
To break or to melt a covalent network solid, covalent bonds must be broken. Because covalent bonds are relatively strong, covalent network solids are typically...
02:42Valence 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...
02:58Crystal 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...
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.
01:12Two-Dimensional (2D) NMR: Overview
The 1D NMR spectrum of large and complex molecules like natural products has complicated splitting patterns and overlapping signals, which can be easily interpreted using 2-dimensional (2D) NMR. Unlike 1D NMR, 2D NMR has two frequency axes that provide the coupling information between the nucleus A and nucleus B in a molecule. The process from which 2D spectra are obtained has four steps.
The first step is the preparation period, during which nucleus A is excited with a radiofrequency pulse.
The first step is the preparation period, during which nucleus A is excited with a radiofrequency pulse.
01:31Ferromagnetism
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...