形成金甲乙烯自组装单层的形成
Yun Wang1, Noel S Hush, Jeffrey R Reimers
1School of Chemistry, The University of Sydney, NSW 2006, Australia.
Journal of the American Chemical Society
|November 9, 2007
概括
这项研究探讨了使用密度函数理论的硫黄自组装单层形成. 在fcc条纹上,在Au(111) 上的二甲基二硫化物化学吸收受到青,导致表面重建和单层形成.
科学领域:
- 表面科学是一门学科.
- 计算化学计算化学
- 材料科学 材料科学 材料科学
背景情况:
- 自组装单层 (SAM) 在表面化学和纳米技术中至关重要.
- 了解黄金SAM形成的能量是应用的关键.
- 黄金表面,特别是Au(111),已被广泛用于SAM的研究.
研究的目的:
- 为了研究黄金自组装单层形成的能量.
- 阐明二甲基二硫化物在Au上的初始吸附和解离路径.
- 为了比较二甲基二硫化物和甲乙醇在黄金表面的形成能量.
主要方法:
- 使用密度功能理论 (DFT) 模拟.
- 计算的重点是重建的Au(111) (22 x radial3) 表面和未重建的Au(111).
- 分析了化学吸收,解离和表面重建的能量.
主要成果:
- 二甲基二硫化物的化学吸收在fcc重建条纹Au(111) 时最有利.
- 最初的物理吸收导致二硫化物解离,阿达托姆/空隙对形成,并在7.8%的硫覆盖率下进行表面重建提升.
- 在较高的覆盖面上单层形成会导致表面坑;甲乙醇吸附是内热的.
结论:
- 硫黄SAM的形成高度依赖于黄金表面结构和吸附物.
- 在重建的Au(111) 上,二甲基二硫化物化学吸收在能量上是有利的,推动了表面的修饰.
- 在研究条件下,在干净,未重建的Au(111) 上的甲乙醇吸附不那么有利.
相关概念视频
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.
02:33Preparation and Reactions of Thiols
Thiols are prepared using the hydrosulfide anion as a nucleophile in a nucleophilic substitution reaction with alkyl halides. For instance, bromobutane reacts with sodium hydrosulfide to give butanethiol.
03:22Colloids
Children at play often make suspensions such as mixtures of mud and water, flour and water, or a suspension of solid pigments in water known as tempera paint. These suspensions are heterogeneous mixtures composed of relatively large particles that are visible to the naked eye or can be seen with a magnifying glass. They are cloudy, and the suspended particles settle out after mixing. On the other hand, a solution is a homogeneous mixture in which no settling occurs and in which the dissolved...