Preparation and characterization of 4'-donor substituted stilbene-4-thiolate monolayers and their influence on the work function of gold.
Preparation and characterization of 4'-donor substituted stilbene-4-thiolate monolayers and their influence on the work function of gold.
复制标题
4-供体取代的二苯乙烯-4-硫醇盐单层的制备和表征及其对金功函数的影响。
DOI：
10.1021/la9004104
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发表时间：
2009
期刊：
影响因子：
--
通讯作者：
S. Marder
中科院分区：
文献类型：
--
作者：
Michal Malicki;Z. Guan;S. Ha;G. Heimel;S. Barlow;M. Rumi;A. Kahn;S. Marder
通过相应的s -乙酰基衍生物的乙醇溶液与金底物反应，在Au（111）上获得了e-二苯乙烯-4-硫代酸酯（SAM1）、E-4'-（乙氧基）二苯乙烯-4-硫代酸酯（SAM2）和E-4'-（二甲氨基）二苯乙烯-4-硫代酸酯（SAM3）自组装单层。x射线光电子能谱、椭偏仪和红外反射吸收光谱的结合表明，单分子层是致密的（约3.3 x 10（14）个分子/cm(2)），硫代酸盐的长分子轴近似垂直于表面。紫外光电子能谱分析表明，这些单分子层的形成使原始Au的功函数降低了0.9 ~ 1.3 eV，部分原因是吸附时形成了约4.4 D/分子的键偶极子，部分原因是4′-pi供体取代基引起的分子偶极矩。然而，SAM1、sam2和sam3之间的功函数变化的程度比纯静电考虑的预期要小。
Self-assembled monolayers of E-stilbene-4-thiolate (SAM1), E-4'-(ethoxy)stilbene-4-thiolate (SAM2), and E-4'-(dimethylamino)stilbene-4-thiolate (SAM3) on Au(111) have been obtained from reaction of ethanol solutions of the corresponding S-acetyl derivatives with gold substrates. A combination of X-ray photoelectron spectroscopy, ellipsometry, and infrared reflection absorption spectroscopy indicates that the monolayers are dense (ca. 3.3 x 10(14) molecules/cm(2)) and that the long molecular axes of the thiolates are approximately perpendicular to the surface. Ultraviolet photoelectron spectroscopy shows that formation of these monolayers decreases the work function of pristine Au by 0.9-1.3 eV, in part due to a bond dipole of ca. 4.4 D/molecule formed upon adsorption and partly due to the molecular dipole moment arising from the 4'-pi-donor substituents. However, the extent of the work function variation between SAM1, 2, and 3 is smaller than anticipated from purely electrostatic considerations.