碳酸ReVII复合物:分子和表面复合物的比较
Mathieu Chabanas1, Anne Baudouin, Christophe Copéret
1Laboratoire de Chimie Organométallique de Surface, UMR 9986 CNRS - ESCPE Lyon, 43 bd du 11 Novembre 1918, F-69626 Villeurbanne Cedex, France.
Journal of the American Chemical Society
|January 9, 2003
概括
这项研究详细介绍了复合物与二氧化的反应,形成了一个特定的同位素. 使用先进的NMR和EXAFS光谱学的表征证实了结构和反应性,揭示了对表面介导反应的洞察力.
科学领域:
- 有机金属化学 有机金属化学
- 表面科学是一门学科.
- 材料化学 材料化学
背景情况:
- 分子复合体为表面功能化提供可调节的反应性.
- 将有机金属复合物移植到二氧化上是创建支持的催化剂和材料的关键策略.
研究的目的:
- 为了研究分子复合物[Re(=CtBu) (((=CHtBu) ((CH2tBu) 2) 与脱氧化的反应.
- 描述所得到的接种的复合物的结构和同位体形式.
- 阐明反应机制以及二氧化表面在指导反应性的作用.
主要方法:
- 复合体与部分脱化二氧化的反应.
- 使用质量平衡分析,红外 (IR) 光谱和1D/2D固态核磁共振 (NMR) 光谱 (包括HETCOR和远程HETCOR) 进行表征.
- 扩展的X射线吸收细结构 (EXAFS) 分析以确定协调环境.
- 热和光化学处理以获取不同的异构体.
主要成果:
- 反应主要产生了syn同位素,syn-2,[(=SiO) Re (((=CtBu) (((=CHtBu) (((CH2tBu))),这是通过光谱数据证实的.
- 固态NMR为所有碳环境提供了详细的分配,包括那些没有同位素标记的环境.
- EXAFS数据显示了与邻近原子的特定距离,与基烯,基烯,基碳和表面氧相一致.
- 在协调球体中存在一个西洛桥的存在是由EXAFS提出的.
- 合成和抗异构体都可访问和表征,化学转移与分子类型相匹配.
- 移植涉及基和基基连接物以同等的概率反应,而基基连接物仍然是旁观者.
结论:
- 复合物的移植到上是通过一种特定的途径进行的,涉及alpha-H抽象,受表面的影响.
- 观察到的单移植复合体的形成,而不是一个trisneopentyl复合体,归因于与邻近的西洛桥的相互作用.
- 这项研究证明了二氧化与有机金属复合物的受控表面功能化,产生了明确的移植物种.
相关概念视频
Carbon Skeletons
Life on Earth is carbon-based, as all macromolecules that make up living organisms contain carbon atoms. All organic compounds have a carbon backbone. Each carbon atom is tetravalent and can bond with four other atoms, making it an extraordinarily flexible component of biological molecules. Because carbon’s valence electrons are stable, it rarely becomes an ion. As the carbon chain increases in length, structural modifications such as ring structures, double bonds, and branching side chains...
Conservative Site-specific Recombination and Phase Variation
Because the DNA segments are cut and reorganized in a direction-specific manner, site-specific recombination has emerged as an efficient genetic engineering technique. Flippase and Cyclization recombinases or Flp and Cre, respectively, are two members of the tyrosine recombinase family derived from bacteriophages, that are used to mediate site-specific DNA insertions, deletions, and targeted expression of proteins in mammalian cell lines.
The recognition sites for Cre recombinase called LoxP...
The recognition sites for Cre recombinase called LoxP...
Carboxylic Acid Derivatives: Overview
Carboxylic acid derivatives are formed by replacing the hydroxyl group of carboxylic acids with a different functional group. The most common carboxylic acid derivatives are:
Radical Reactivity: Overview
Radicals, the highly reactive species, gain stability by undergoing three different reactions. The first reaction involves a radical-radical coupling, in which a radical combines with another radical, forming a spin‐paired molecule. The second reaction is between a radical and a spin‐paired molecule, generating a new radical and a new spin‐paired molecule. The third reaction is radical decomposition in a unimolecular reaction, forming a new radical and a spin‐paired molecule. These three...
Characteristics and Nomenclature of Copolymers
Copolymers are the products obtained from the polymerization of multiple monomer species. So, in a polymer chain itself, there can be multiple repeating units that come from different monomers. The process of synthesizing a polymer from different monomer species is called copolymerization. When two monomers are involved, the polymer is known as a bipolymer. Polymers with three and four monomers are termed terpolymers and quaterpolymers, respectively. Figure 1 depicts the copolymerization of...
Classification and Mechanical Properties of Synthetic Polymers
Synthetic polymers are classified as elastomers, fibers, or plastics based on their crystallinity. Crystallinity, the degree of long-range order in the solid state, influences the mechanical properties (stretching or contracting) of elastomers. Elastomers are flexible polymers that can expand or contract easily upon the application of an external force. They have numerous crosslinks that pull them back into their original shape when stress is removed. Silicones, for instance, are highly elastic...


