碳的气相氧化物功能化
Eric D Stenehjem1, Vadim R Ziatdinov, T Daniel P Stack
1Department of Chemistry, Stanford University, Stanford, California 94305, USA.
Journal of the American Chemical Society
|January 11, 2013
概括
研究人员开发了一种安全且可扩展的方法,使用气态酸来修改碳表面的亚基. 这种功能使分子通过点击化学能够坚固地附着,为各种应用增强碳材料.
科学领域:
- 材料科学 材料科学 材料科学
- 表面化学 表面化学
- 有机化学 有机化学
背景情况:
- 碳材料的表面和接口性能对于催化,储能和分离的应用至关重要.
- 现有的碳表面修改方法可能是低效的,或者产生大量的废物.
- 开发可扩展和选择性功能化技术对于推进碳技术至关重要.
研究的目的:
- 引入一种新且安全的方法,利用气态酸进行碳表面的亚化改性.
- 为了证明化物修饰碳表面的实用性,作为进一步功能化的多功能平台.
- 探索修改和随后的点击反应的稳定性和效率.
主要方法:
- 从单化物和酸中在线生成气态酸.
- 用气态酸流直接处理碳表面,以实现功能化.
- 铜催化亚酸环添加 (CuAAC) "点击"反应以附加乙烯.
- 电压度和X射线光电子光谱 (XPS) 分析以量化铁素覆盖面.
主要成果:
- 建立了一种安全,方便,可重现,选择性和可扩展的碳表面的亚齐德功能化方法.
- 亚化物修饰的表面很容易经历CuAAC点击化学反应,使得像乙烯铁素这样的分子能够高效地附着.
- 在玻璃碳表面上实现了高铁素覆盖率 (高达8×10^13分子/厘米2).
- 由此产生的1,2,3-triazole链接剂在恶劣的酸性和基本性条件下表现出极好的水解稳定性.
结论:
- 气态酸为碳材料的可扩展性酸改性提供了一种有效和多用途的试剂.
- 亚酸功能化碳表面是通过点击化学引入各种功能的坚固平台.
- 这种方法为各种应用提供了减少废物的高效途径,以获得先进的碳基材料.
相关概念视频
Preparation of 1° Amines: Azide Synthesis
Direct alkylation of ammonia produces polyalkylated amines, along with a quaternary ammonium salt. To exclusively prepare primary amines, the azide synthesis method can be used.
Azide ions act as good nucleophiles and react with unhindered alkyl halides to form alkyl azides. Alkyl azides do not participate in further nucleophilic substitution reactions, thereby eliminating the chances of polyalkylated products. Alkyl azides are reduced by hydride-based reducing agents, like lithium aluminum...
Azide ions act as good nucleophiles and react with unhindered alkyl halides to form alkyl azides. Alkyl azides do not participate in further nucleophilic substitution reactions, thereby eliminating the chances of polyalkylated products. Alkyl azides are reduced by hydride-based reducing agents, like lithium aluminum...
Diazonium Group Substitution: –OH and –H
Nitrous acid, a weak acid, is prepared in situ via the reaction of sodium nitrite with a strong acid under cold conditions. This nitrous acid prepared in situ reacts with primary arylamines to form arenediazonium salts. Such reactions are known as diazotization reactions. As shown in Figure 1, the formation of arenediazonium salts begins with the decomposition of nitrous acid in an acidic solution to give nitrosonium ions.
Diazonium Group Substitution with Halogens and Cyanide: Sandmeyer and Schiemann Reactions
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...
Carboxylic Acids to Methylesters: Alkylation using Diazomethane
Carboxylic acids react with diazomethane in an ether solvent via alkylation at the carboxylate oxygen atom to give methyl esters of the corresponding acid with excellent yields.
Nucleophilic Aromatic Substitution of Aryldiazonium Salts: Aromatic SN1
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, or cyano...
In the Sandmeyer reaction, for example, the diazonio group is replaced by a chloro, bromo, or cyano...
1° Amines to Diazonium or Aryldiazonium Salts: Diazotization with NaNO2 Mechanism
Nitrous acid is a relatively weak and unstable acid prepared in situ by the reaction of sodium nitrite and cold, dilute hydrochloric acid. In an acidic solution, the nitrous acid undergoes protonation when it loses water to form a nitrosonium ion—an electrophile. Nitrous acid reacts with primary amines to give diazonium salts. The reaction is called diazotization of primary amines.


