在被吸附的铁四甲氨酸分子之间转移Cl联体
Thiruvancheril G Gopakumar1, Hao Tang, Joseph Morillo
1Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, 24098 Kiel, Germany. gopa@physik.uni-kiel.de
Journal of the American Chemical Society
|July 4, 2012
概括
从铁四甲二烯化物 (FeTPPCl) 到扫描道显微镜尖端实现了控制的转移. 这一过程涉及电子去除和铁氧化状态的变化,保存了分子模式.
科学领域:
- 表面科学是一门学科.
- 纳米技术 纳米技术
- 材料化学 材料化学
背景情况:
- 铁四基化 (FeTPPCl) 是一种分子,在催化和分子电子学中具有潜在的应用.
- 了解分子-表面相互作用对于设计纳米级设备至关重要.
- 在单个分子水平上控制化学反应是纳米科学的一个关键挑战.
研究的目的:
- 为了研究FeTPPCl从黄金 (Au) 表面上被吸附的 (Cl) 的受控转移.
- 探索由电子去除引发的Cl抽象机制.
- 检查操纵单个分子而不扰乱周围环境的可行性.
主要方法:
- 低温扫描道显微镜 (LT-STM) 用于成像和操纵FeTPPCl分子.
- 从最高占成的分子轨道 (HOMO) 中进行控制的电子去除,用于启动Cl抽象.
- 进行密度函数理论 (DFT) 计算,以了解反应期间的电子和结构变化.
主要成果:
- 证明了Cl从FeTPPCl的Fe中心到STM尖端的成功可控的Cl转移.
- 通过从FeTPPCl分子中去除电子来启动Cl抽象过程.
- 周围的分子模式在操纵过程中保持完整,表明高选择性.
- DFT计算表明反应期间铁 (Fe) 离子的氧化状态发生了变化.
结论:
- 使用LT-STM,可以实现FeTPPCl的单分子操纵,包括Cl转移.
- 电子诱导的Cl抽象是一种可行的途径,可以在纳米尺度上修改氨酸分子.
- 观察到的控制和选择性为表面化学合成和分子设备制造提供了新的可能性.
相关概念视频
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...
02:58Crystal 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...
01:28The Early Endosome: Endocytosis of Transferrin
Essential proteins such as insulin or low-density lipoprotein (LDL) and micronutrients such as iron enter a eukaryotic cell through receptor-mediated endocytosis. Subsequently, the early endosomes fuse with the vesicles containing such receptor-ligand complexes and play a vital role in sorting the incoming ligands and receptors. While the ligands are either degraded inside the vesicle or released into the cytosol, their receptors are returned to the plasma membrane for further rounds of...
00:56Extraction: Advanced Methods
Metal ions can be separated from one another by complexation with organic ligands–the chelating agent– to form uncharged chelates. Here, the chelating agent must contain hydrophobic groups and behave as a weak acid, losing a proton to bind with the metal. Since most organic ligands used in this process are insoluble or undergo oxidation in the aqueous phase, the chelating agent is initially added to the organic phase and extracted into the aqueous phase. The metal-ligand complex is formed in...
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.