A Comprehensive Study of Self-Assembled Monolayers of Anthracenethiol on Gold: Solvent Effects, Structure, and Stability
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- 作者：Daniel Kä ; fer ; Gregor Witte ; Piotr Cyganik ; Andreas Terfort ; and Christof Wö ; ll
- 刊名：Journal of the American Chemical Society
- 出版年：2006
- 出版时间：February 8, 2006
- 年：2006
- 卷：128
- 期：5
- 页码：1723 - 1732
- 全文大小：746K
- 年卷期：v.128,no.5(February 8, 2006)
- ISSN：1520-5126
文摘
The formation and molecular structure of self-assembled monolayers (SAMs) of anthracene-2-thiol (AnT) on Au(111) have been characterized by reflection adsorption infrared spectroscopy, thermaldesorption spectroscopy, X-ray photoelectron spectroscopy, near-edge X-ray absorption spectroscopy,scanning tunneling microscopy, and low energy electron diffraction. It is demonstrated that highly orderedmonolayer films are formed upon immersion, but their quality depends critically on the choice of solventsand rinsing conditions. The saturated monolayer is characterized by a closed packed arrangement of uprightstanding molecules forming a (2
journals/jacsat/128/i05/eqn/ja0571592e10001.gif"> × 4)rect unit cell. At about 450 K a partial desorption takes place andthe remaining molecules form a dilute (4 × 2)-phase with an almost planar adsorption geometry, whilefurther heating above 520 K causes a thermally induced fragmentation. According to their different densitiesboth phases reveal very diverse chemical reactivities. Whereas the saturated monolayer is stable andinert under ambient conditions, the dilute phase does not warrant any protection of the sulfur headgroupswhich oxidize rapidly in air.