Adsorption Site Determination for Au-Octanethiolate on Au(111)

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• 作者：Fangsen Li ; Lin Tang ; Wancheng Zhou ; Quanmin Guo
• 刊名：Langmuir
• 出版年：2010
• 出版时间：June 15, 2010
• 年：2010
• 卷：26
• 期：12
• 页码：9484-9490
• 全文大小：1147K
• 年卷期：v.26,no.12(June 15, 2010)
• ISSN：1520-5827

文摘

Self-assembled monolayers (SAMs) of Au-octanethiolate on Au(111) have been studied using scanning tunneling microscopy (STM). Thermal annealing of the dense (√3 × √3)R30° layer at 353 K for 1 h leads to the formation of a (5√3 × √3)R30° striped phase coexisting with the (√3 × √3)R30° phase. High-resolution STM imaging shows that the unit cell of the (5√3 × √3)R30° phase consists of four adsorbed Au-thiolate species giving rise to an adsorbate coverage of 0.27 ML. The four Au-thiolate species take the standing-up orientation and occupy inequivalent adsorption sites: one on a bridge site and three on the hollow sites. By drawing connections between the (5√3 × √3)R30° and the (√3 × √3)R30° phases, it is found that the adsorption site for Au-thiolate inside the (√3 × √3)R30° phase must be either the fcc hollow or the hcp hollow site.