在固体硫酸薄膜上的表面分子酸的识别
Suzanne B Couling1, Karen L Nash, John Fletcher
1Department of Chemistry, University of York, Heslington, York YO1 5DD, UK.
Journal of the American Chemical Society
|October 23, 2003
概括
在离子硫酸表面上的一种稳定的分子水合物与氨反应. 这种反应发生得很快,直到耗尽,然后是一个更慢的,扩散有限的过程,涉及表面离子.
科学领域:
- 大气化学 大气化学
- 表面科学是一门学科.
背景情况:
- 离子硫酸水合物在凝结的薄膜上形成稳定的分子水合物.
- 这些表面水合物会影响化学反应.
研究的目的:
- 研究表面分子酸盐在氨与离子硫酸酸盐相互作用中的作用.
- 为了阐明所涉及的反应机制.
主要方法:
- 红外光谱学 红外光谱学 红外光谱学
- 二次离子质谱学二次离子质谱学
主要成果:
- 在离子硫酸水合物表面发现了一种稳定的分子水合物.
- 氨与这种表面物种迅速反应,直到其耗尽.
- 在氨和表面离子 (H3O+) 之间观察到较慢,扩散有限的反应.
结论:
- 表面的分子水合物是氨的关键反应点.
- 反应动力学受到快速表面反应和较慢的扩散控制过程的影响.
相关概念视频
02:45Acid-Catalyzed Hydration of Alkenes
Alkenes react with water in the presence of an acid to form an alcohol. In the absence of acid, hydration of alkenes does not occur at a significant rate, and the acid is not consumed in the reaction. Therefore, alkene hydration is an acid-catalyzed reaction.
02:40Alkynes to Aldehydes and Ketones: Acid-Catalyzed Hydration
Introduction
Analogous to alkenes, alkynes also undergo acid-catalyzed hydration. While the addition of water to an alkene gives an alcohol, hydration of alkynes produces different products such as aldehydes and ketones.
Analogous to alkenes, alkynes also undergo acid-catalyzed hydration. While the addition of water to an alkene gives an alcohol, hydration of alkynes produces different products such as aldehydes and ketones.
02:26Preparation and Reactions of Sulfides
Sulfides are the sulfur analog of ethers, just as thiols are the sulfur analog of alcohol. Like ethers, sulfides also consist of two hydrocarbon groups bonded to the central sulfur atom. Depending upon the type of groups present, sulfides can be symmetrical or asymmetrical. Symmetrical sulfides can be prepared via an SN2 reaction between 2 equivalents of an alkyl halide and one equivalent of sodium sulfide.
01:01Acid Halides to Carboxylic Acids: Hydrolysis
Hydrolysis of acid halides is a nucleophilic acyl substitution reaction in which acid halides react with water to give carboxylic acids. The reaction occurs readily and does not require acid or a base catalyst.
As shown below, the mechanism involves a nucleophilic attack by water at the carbonyl carbon to form a tetrahedral intermediate. This is followed by the reformation of the carbon–oxygen π bond along with the departure of a halide ion. A final proton transfer step yields carboxylic acid...
As shown below, the mechanism involves a nucleophilic attack by water at the carbonyl carbon to form a tetrahedral intermediate. This is followed by the reformation of the carbon–oxygen π bond along with the departure of a halide ion. A final proton transfer step yields carboxylic acid...