Solvent-dependent assembly of terphenyl- and quaterphenyldithiol on gold and gallium arsenide
Solvent-dependent assembly of terphenyl- and quaterphenyldithiol on gold and gallium arsenide
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DOI：
10.1021/la0503000
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发表时间：
2005-06-21
期刊：
影响因子：
3.9
通讯作者：
Loo, YL
中科院分区：
文献类型：
--
作者：
Krapchetov, DA;Ma, H;Loo, YL
三联苯二硫醇（TPDT）和四联苯二硫醇（QPDT）的组装金和砷化镓从乙醇（EtOH），四氢呋喃（THF），和由这两种溶剂组成的溶液已被其特征在于通过近边X射线吸收精细结构光谱。TPDT和QPDT在金上的表面覆盖率和平均取向度与溶剂无关。这些分子很容易在金上形成单层，其整体平均骨架与基底法线的倾斜度为30度+/-3度。与此形成鲜明对比的是，砷化镓上TPDT和QPDT的组装对溶剂非常敏感。在高乙醇分数，这两种分子形成的单层与整体平均取向，是无法区分的金基板上的。然而，在低乙醇分数和纯THF中，这些分子在砷化镓上是无序的，并且表面覆盖率很差。
The assembly of terphenyldithiol (TPDT) and quaterphenyldithiol (QPDT) on gold and gallium arsenide from ethanol (EtOH), tetrahydrofuran (THF), and solutions consisting of both solvents has been characterized by near-edge X-ray absorption fine structure spectroscopy. The surface coverage and the average orientation of both TPDT and QPDT on gold are solvent-independent. These molecules readily form monolayers on gold with an ensemble-average backbone tilt of 30 degrees +/- 3 degrees from the substrate normal. In sharp contrast, the assembly of TPDT and QPDT on gallium arsenide is extremely solvent-sensitive. At high ethanol fractions, both molecules form monolayers with an ensemble-average orientation that is indistinguishable from those on gold substrates. At low ethanol fractions and in pure THF, however, these molecules are disordered on gallium arsenide and the surface coverage is poor.