新型[60]富勒烯双添加物的区域选择性合成和特性,含有双冠乙部分
Yosuke Nakamura1, Aya Asami, Toshio Ogawa
1Department of Chemistry, Gunma University, Tenjin-cho, Kiryu, Gunma 376-8515, Japan.
Journal of the American Chemical Society
|April 19, 2002
概括
研究人员探索了[60]富勒与皇冠前体的反应. 某些富勒-皇冠乙烯双添加物显示出显著的离子复合,表现优于传统的二-18-皇冠-6.
科学领域:
- 超分子化学 超分子化学
- 有机化学 有机化学
- 材料科学 材料科学 材料科学
背景情况:
- 富勒伦是具有独特电子性质的多功能碳异构体.
- 皇冠乙烯以它们的选择性离子结合能力而闻名.
- 将富勒与皇冠乙烯结合起来,可以产生具有量身定制的离子电离性质的新材料.
研究的目的:
- 为了研究[60]富勒与具有不同皇冠以太分量的 bis-o-quinodimethane 前体的反应性.
- 为了表征由此产生的富勒双添加物,并评估它们的离子结合特性.
- 为了比较这些新的富勒烯-皇冠以太结合物与父皇冠以太的离子选择性.
主要方法:
- 用双-18-皇冠-6,24-皇冠-8和30-皇冠-10功能化的双-o-二甲基前体的合成.
- [60]富勒烯与合成的前体的反应.
- 用光谱技术分离和描述富勒烯双添加物.
- 使用离子选择性电极确定离子结合特性和选择性系数.
主要成果:
- [60]富勒烯与前体的反应产生了各种区域异构体双添加物,其中两种前体的主要产物是trans-4双添加物.
- 一个前体独家提供了*e* bisadduct.
- 双添加物6a和7b对K+离子具有很高的复杂化能力,选择性系数明显高于dibenzo-18-crown-6.
- 乙酸6b与金属离子的复合是最小的.
结论:
- 富勒烯双形成的区域选择性可能会受到结合的皇冠部分的影响.
- 新的富勒 - 皇冠以太结合物表现出增强的离子体特性,特别是K+离子.
- 这些发现表明在离子传感和分离技术中的潜在应用.
相关概念视频
Regioselectivity of Electrophilic Additions-Peroxide Effect
In the presence of organic peroxides, the addition of hydrogen bromide to an alkene yields the isomer that is not predicted by Markovnikov’s rule. For example, the addition of hydrogen bromide to 2-methylpropene in the presence of peroxides gives 1-bromo-2-methylpropane. This addition reaction proceeds via a free radical mechanism, which reverses the regioselectivity. The free radical reaction mechanism involves three stages: initiation, propagation, and termination.
Characteristics and Nomenclature of Homopolymers
Polymers that are made up of identical monomer units are called homopolymers. Only one repeating unit is involved in the construction of the homopolymer structure. For example, as depicted in Figure 1, polypropylene is a homopolymer constituted of propylene monomers. Here, the only repeating unit in the polymer chain is propylene.
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...
Polymer Classification: Architecture
Polymers are classified as linear or branched on the basis of their chain architecture. The polymer chains in linear polymers have a long chain-like structure with minimal to no branching at all. Even if a polymer features large substituent groups on the monomer, which appear as branches to the skeleton, it is not considered a branched polymer. A branched polymer contains secondary polymer chains that arise from the main polymer chain. The branching occurs when the polymer growth shifts from...
Polymer Classification: Stereospecificity
Polymerization generates chiral centers along the entire backbone of a polymer chain. Accordingly, the stereochemistry of the substituent group has a significant effect on polymer properties. Polymers formed from monosubstituted alkene monomers feature chiral carbons at every alternate position in the polymer backbone. Relative to the predominant orientation of substituents at the adjacent chiral carbons, the polymer can exist in three different configurations: isotactic, syndiotactic, and...
Olefin Metathesis Polymerization: Overview
Recently, the development of olefin metathesis polymerization advanced the field of polymer synthesis. Simply put, the reorganization of substituents on their double bonds between two olefins in the presence of a catalyst is known as the olefin metathesis reaction. The use of metathesis reaction for polymer synthesis is called olefin metathesis polymerization.
Ruthenium-based Grubbs catalyst is the most commonly used catalyst for olefin metathesis polymerization. Grubbs catalyst consists of a...
Ruthenium-based Grubbs catalyst is the most commonly used catalyst for olefin metathesis polymerization. Grubbs catalyst consists of a...


