Kristensen Jytte, Zhang Jingdong, Chorkendorff Ib, Ulstrup Jens, Ooi Bee Lean
Department of Chemistry, NanoDTU, Technical University of Denmark, Building 207, Kemitorvet, 2800, Lyngby, Denmark.
Dalton Trans. 2006 Sep 7(33):3985-90. doi: 10.1039/b608949f. Epub 2006 Jul 31.
A class of inorganic monolayers formed by assembling the molybdenum-sulfur cluster, Mo3S4(4+), onto a well-defined Au(111) surface is presented. The monolayers have been comprehensively characterized by electrochemistry, X-ray photoelectron spectroscopy (XPS), and in situ scanning tunneling microscopy (in situ STM). The voltammetric data show strong reductive and oxidative desorption signals from Au-S interactions, supported by the presence of both S and Mo signals in XPS. In situ STM shows many small pits in the dense adlayers uniformly spread over the surface, which is a typical feature of self-assembled monolayers (SAMs) of alkanethiols. The density of the pits is ca. 23 (+/-5)% and is significantly higher than for straight-chain alkanethiol SAMs with a single -SH group. The pit shapes are irregular, suggesting multiple Au-S interactions from Mo3S4(4+). High resolution images disclose bright round spots of ca. 8 A diameter representing individual molecules in the SAM. This is the first example of in situ monolayer formation by a metal-chalcogenide cluster directly anchored onto the gold surface through core ligands and offers a simple way to prepare a new class of functionalized inorganic monolayers.
本文介绍了一类通过将钼硫簇合物Mo3S4(4+)组装到定义明确的Au(111)表面而形成的无机单层。这些单层已通过电化学、X射线光电子能谱(XPS)和原位扫描隧道显微镜(in situ STM)进行了全面表征。伏安数据显示出源于Au-S相互作用的强烈还原和解吸信号，XPS中S和Mo信号的存在支持了这一点。原位STM显示在致密吸附层中有许多小坑均匀分布在表面，这是链烷硫醇自组装单层(SAMs)的典型特征。坑的密度约为23(±5)%，明显高于具有单个-SH基团的直链链烷硫醇SAMs。坑的形状不规则，表明Mo3S4(4+)存在多个多个多个分子内多重Au-S相互作用。高分辨率图像揭示了直径约为8 Å的明亮圆形斑点，代表SAMs中的单个分子。这是金属硫族化物簇通过核心配体直接锚定在金表面原位形成单层的首个实例，并提供了一种制备新型功能化无机单层的简单方法。
