Substituent effect on the intermolecular arrangements of one-dimensional molecular assembly on the Si(100)-(2x1)-H surface
Substituent effect on the intermolecular arrangements of one-dimensional molecular assembly on the Si(100)-(2x1)-H surface
复制标题
取代基对Si(100)-(2x1)-H表面一维分子组装体分子间排列的影响
DOI：
10.1021/jp308770t
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发表时间：
2013
期刊：
影响因子：
3.7
通讯作者：
M. Kawai
中科院分区：
文献类型：
--
作者：
M.Z. Hossain;H.S. Kato;M. Kawai
利用扫描隧道显微镜（STM）研究了300 K时苯乙烯分子中甲基取代对Si（100）-（2×1）-H表面一维分子组装中分子空间排列的影响.苯乙烯分子沿着二聚体行方向通过链式反应机制形成明确的一维分子组装体，其中苯环以等于行中二聚体间距离的距离分开，并且彼此平行排列。我们观察到，取代在苯环上的吸附位点，配置，和堆叠的苯环沿着二聚体行没有明显的影响。与此相反，在α位的甲基取代（α-甲基苯乙烯）的结果在1-D组装，其中的吸附位点是类似的苯乙烯，但吸附的分子排列在交替的几何构型沿着二聚体行。在β-甲基苯乙烯的情况下，吸附位点（二聚体行中的对角硅原子）和吸附分子沿着二聚体行的几何构型不同于苯乙烯。这些结果表明，在1-D组装的分子的选择性排列可以通过诱导空间位阻通过在反应分子的特定位点的取代来实现。
The effect of methyl substitution in styrene molecules on the spatial arrangement of molecules in a one-dimensional (1-D) molecular assembly on the Si(100)-(2×1)-H surface has been studied using a scanning tunneling microscope (STM) at 300 K. Styrene molecules form well-defined 1-D molecular assemblies through a chain reaction mechanism along the dimer row direction, where the phenyl rings are separated by distances equal to that of the interdimer distance in a row and aligned parallel to each other. We observed that the substitution in a phenyl ring has no observable effect on the adsorption sites, configurations, and stacking of phenyl rings along the dimer row. In contrast, the methyl substitution at α site (α-methylstyrene) results in a 1-D assembly where the adsorption sites are similar to that of styrene but the adsorbed molecules are arranged in alternate geometrical configurations along the dimer row. In the case of β-methylstyrene, the adsorption sites (diagonal silicon atoms in a dimer row) and the geometrical configurations of adsorbed molecules along the dimer row are different from that of styrene. These results suggest that the selective arrangement of the molecules in a 1-D assembly can be achieved by inducing a steric hindrance through substitution at specific sites of the reacting molecule.