金属涂层对金表面自组装单分子层的影响。2. 铜在亚苯基乙炔低聚物单分子层上的情况。

Effects of metal coating on self-assembled monolayers on gold. 2. Copper on an oligo(phenylene-ethynylene) monolayer.

作者信息

Colavita Paula E, Miney Paul G, Taylor Lindsay, Priore Ryan, Pearson Darren L, Ratliff Jay, Ma Shuguo, Ozturk Osman, Chen Donna A, Myrick M L

机构信息

Department of Chemistry and Biochemistry, University of South Carolina, 631 Sumter Street, Columbia, South Carolina 29208, USA.

出版信息

Langmuir. 2005 Dec 20;21(26):12268-77. doi: 10.1021/la051389c.

DOI:10.1021/la051389c

PMID:16343002

Abstract

We report studies on the modifications induced by the evaporation of copper overlayers on a self-assembled monolayer (SAM) of the oligo(phenylene-ethynyl) dithiol, 1-thio-4-[4'-[(4'-thio)phenylethynyl]-1'-ethynyl]-benzene (TTPEB). These SAMs were characterized after deposition from a tetrahydrofuran solution on polycrystalline gold substrates and after copper evaporation and its subsequent removal by nitric acid. Monolayers were studied via cyclic voltammetry (CV), UV-vis multiwavelength ellipsometry, external reflectance infrared (IR) spectroscopy, and ion scattering spectroscopy (ISS). The results obtained indicate that TTPEB SAMs display the same packing characteristics before and after copper evaporation and removal. However, as shown by IR spectroscopy, the monolayers undergo a reorganization process that involves an increase in tilt angle accompanied by rotation of aromatic rings that results in a decrease in the average molecular twist angle. ISS data suggest that copper diffuses through the monolayer after copper evaporation, a result that is significant for applications of this molecule in molecular electronic devices.

摘要

我们报告了关于在低聚（亚苯基乙炔）二硫醇1-硫代-4-[4'-[(4'-硫代)苯乙炔基]-1'-乙炔基]-苯（TTPEB）的自组装单分子层（SAM）上蒸发铜覆盖层所引起的改性研究。这些自组装单分子层在从四氢呋喃溶液沉积到多晶金基底上之后，以及在铜蒸发及其随后用硝酸去除之后进行了表征。通过循环伏安法（CV）、紫外-可见多波长椭偏仪、外反射红外（IR）光谱和离子散射光谱（ISS）对单分子层进行了研究。所获得的结果表明，TTPEB自组装单分子层在铜蒸发和去除前后显示出相同的堆积特征。然而，如红外光谱所示，单分子层经历了一个重组过程，该过程涉及倾斜角的增加以及芳香环的旋转，从而导致平均分子扭曲角减小。离子散射光谱数据表明，铜蒸发后铜会扩散穿过单分子层，这一结果对于该分子在分子电子器件中的应用具有重要意义。