相关实验视频
Updated: Jul 9, 2026

10:37
Spatial Separation of Molecular Conformers and Clusters
Published on: January 9, 2014
空间控制的苏苏基和赫克催化分子合
Jason J Davis1, Claire B Bagshaw, Katerina L Busuttil
1Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Mansfield Road, OX1 3TA, UK. jason.davis@chem.ox.ac.uk
Journal of the American Chemical Society
|October 26, 2006
概括
研究人员使用了改性原子力显微镜 (AFM) 探头来精确控制表面限制的苏子基和赫克合反应. 这种方法可以在纳米尺度上实现"化学写作反应",用于先进的纳米制造.
科学领域:
- 纳米技术和材料科学 材料科学
- 表面化学和催化剂
- 原子力显微镜 (AFM) 的应用
背景情况:
- 从底部向上的纳米制造需要精确控制纳米级的化学反应.
- 表面限制的碳-碳合反应对于构建复杂的分子结构至关重要.
- 现有的方法往往缺乏复杂的纳米尺度图案所需的空间分辨率和控制.
研究的目的:
- 展示使用催化活性AFM探头来启动和控制局限于表面的合反应.
- 使用催化器的有机金属反应来实现高分辨率的化学图案.
- 量化反应速率和效率在子质粒度水平.
主要方法:
- 利用一个修改了的AFM探测器作为催化剂来启动木和赫克合反应.
- 通过扫描基板表面的AFM探测器进行空间控制的反应.
- 使用横向力显微镜和特定化学品的标签检测和描述了模式反应.
主要成果:
- 实现了空间控制的表面限制的苏苏基和赫克碳-碳合反应,线宽低至15 nm.
- 证明了"化学写作反应"在亚密度分子水平,相当于每个模式大约20个分子.
- 解决的周转数为 (0.6-1.2) x 10^4 分子 s^-1 对于苏子反应和 (3.0-5.0) x 10^4 分子 s^-1 对于赫克反应.
结论:
- 一个修改了的AFM探测器可以精确启动和空间控制表面限制的合反应.
- 这种技术允许以高分辨率和高效率进行纳米级化学图案.
- 该方法为自下而上的纳米制造和在分子水平上研究催化反应提供了一个强大的工具.
相关概念视频
Hybridization of Atomic Orbitals I
The mathematical expression known as the wave function, ψ, contains information about each orbital and the wavelike properties of electrons in an isolated atom. When atoms are bound together in a molecule, the wave functions combine to produce new mathematical descriptions that have different shapes. This process of combining the wave functions for atomic orbitals is called hybridization and is mathematically accomplished by the linear combination of atomic orbitals. The new orbitals that...
Molecular Orbital Theory II
Molecular Orbital Energy Diagrams
Regioselectivity and Stereochemistry of Hydroboration
A significant aspect of hydroboration–oxidation is the regio- and stereochemical outcome of the reaction.
Hydroboration proceeds in a concerted fashion with the attack of borane on the π bond, giving a cyclic four-centered transition state. The –BH2 group is bonded to the less substituted carbon and –H to the more substituted carbon. The concerted nature requires the simultaneous addition of –H and –BH2 across the same face of the alkene giving syn stereochemistry.
Hydroboration proceeds in a concerted fashion with the attack of borane on the π bond, giving a cyclic four-centered transition state. The –BH2 group is bonded to the less substituted carbon and –H to the more substituted carbon. The concerted nature requires the simultaneous addition of –H and –BH2 across the same face of the alkene giving syn stereochemistry.
Cooperative Allosteric Transitions
Cooperative allosteric transitions can occur in multimeric proteins, where each subunit of the protein has its own ligand-binding site. When a ligand binds to any of these subunits, it triggers a conformational change that affects the binding sites in the other subunits; this can change the affinity of the other sites for their respective ligands. The ability of the protein to change the shape of its binding site is attributed to the presence of a mix of flexible and stable segments in the...
Electrophilic Addition of HX to 1,3-Butadiene: Thermodynamic vs Kinetic Control
The addition of a hydrogen halide to 1,3-butadiene gives a mixture of 1,2- and 1,4-adducts. Since more substituted alkenes are more stable, the 1,4-adduct is expected to be the major product. However, the product distribution is strongly influenced by temperature; low temperature favors the 1,2-adduct, whereas the 1,4-adduct is predominant at high temperature.
Heterogeneous Catalysis
Heterogeneous catalysis involves a catalyst in a different phase from the reactants. It is a process where the catalyst and the reactants are in distinct phases, typically solid and gas or liquid.Most heterogeneous catalysts are metals, metal oxides, or acids. The list includes transition metals like iron (Fe), cobalt (Co), nickel (Ni), palladium (Pd), platinum (Pt), chromium (Cr), manganese (Mn), tungsten (W), silver (Ag), and copper (Cu). These metals possess partially vacant d orbitals that...

