分子浸的纳米粒子:有效的,无添加剂的异质催化剂,用于化
Bijnaneswar Mondal1, Koushik Acharyya1, Prodip Howlader1
1Department of Inorganic and Physical Chemistry, Indian Institute of Science , Bangalore 560012, India.
Journal of the American Chemical Society
|January 16, 2016
概括
新的共价稳定了超细纳米粒子 (PdNP),防止聚合. 这些稳定,多孔的体PdNP证明了化酸的有效和可循环催化.
科学领域:
- 超分子化学
- 材料科学
- 纳米技术
背景情况:
- 体提供可调节的多孔结构来封装客分子.
- 稳定超细金属纳米粒子对于催化应用至关重要.
- 控制纳米粒子大小和防止聚合仍然是一个挑战.
研究的目的:
- 合成和描述新的形状持久的共价.
- 用这些子来控制纳米颗粒 (PdNP) 的合成和稳定.
- 评估由此产生的嵌PdNP的催化性能和稳定性.
主要方法:
- 来自三化物和二胺的动态胺化学合成.
- 用于子表征的光谱技术 (NMR,质谱).
- 传输电子显微镜 (TEM),扫描电子显微镜 (SEM) 和粉末X射线衍射 (PXRD) 用于PdNP分析.
- 用于确定负荷的诱导合等离子光学发射光谱学.
主要成果:
- 两种共价,CC1 (((r) ([2+3]组件) 和CC2 (((r) ([8+12]组件),已经成功合成.
- 具有控制尺寸 (∼1.8 nm和∼3.7 nm) 的嵌PdNP (Pd@CC1(r) 得到了实现.
- 在没有子中合成的PdNP显示出显著的聚合.
- Pd@CC1{r}和Pd@CC2{r}的含量分别高 (40%和25%).
结论:
- 形状持久的共价有效地稳定了超细的纳米粒子.
- 子结构可以防止纳米粒子聚合,提高稳定性.
- 在温和条件下,稳定PdNP在化中表现出高效,可回收的催化活性.
相关概念视频
Diazonium Group Substitution with Halogens and Cyanide: Sandmeyer and Schiemann Reactions
2.7K
Arenediazonium substitution reactions occur when the diazonium group is substituted by various functional groups such as halides, hydroxyl, nitrile, etc. For instance, arenediazonium salts react with copper(I) salts of chloride, bromide, or cyanide to form corresponding aryl chlorides, bromides, and nitriles. These reactions are named Sandmeyer reactions. Although the mechanism of this reaction is complicated, as illustrated in Figure 1, they are believed to progress via an aryl copper...
2.7K
Aldehydes and Ketones with HCN: Cyanohydrin Formation Overview
4.3K
Cyanohydrins are compounds that contain –CN and –OH groups on the same carbon atom. They are formed by the nucleophilic addition of the cyanide ions to the carbonyl group. Cyanide ions are highly basic and nucleophilic and can be generated from HCN under aqueous conditions. However, since HCN is a weak acid, the number of cyanide ions generated is very small. Hence, a small amount of base or KCN/NaCN is added to HCN to increase the concentration of the cyanide ions in the reaction...
4.3K
Nucleophilic Aromatic Substitution: Elimination–Addition
5.4K
Simple aryl halides do not react with nucleophiles. However, nucleophilic aromatic substitutions can be forced under certain conditions, such as high temperatures or strong bases. The mechanism of substitution under such conditions involves the highly unstable and reactive benzyne intermediate. Benzyne contains equivalent carbon centers at both ends of the triple bond, each of which is equally susceptible to nucleophilic attack. This 50–50 distribution of products is...
5.4K
Nucleophilic Aromatic Substitution of Aryldiazonium Salts: Aromatic SN1
3.0K
Treating arylamines with nitrous acid gives aryldiazonium salts that are effective substrates in nucleophilic aromatic substitution reactions. The diazonio group in these salts can be easily displaced by different nucleophiles, yielding a wide variety of substituted benzenes. The leaving group departs as nitrogen gas, and this easy elimination is the driving force for the substitution reaction.
In the Sandmeyer reaction, for example, the diazonio group is replaced by a chloro, bromo,...
In the Sandmeyer reaction, for example, the diazonio group is replaced by a chloro, bromo,...
3.0K


![[DPEPhosbcpCu]PF6: A General and Broadly Applicable Copper-Based Photoredox Catalyst](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F59739.jpg&w=3840&q=50)