Interplay of Anchoring and Ordering in Aromatic Self-Assembled Monolayers

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• 作者：Daniel Kä ; fer ; Asif Bashir ; Gregor Witte
• 刊名：Journal of Physical Chemistry C
• 出版年：2007
• 出版时间：July 19, 2007
• 年：2007
• 卷：111
• 期：28
• 页码：10546 - 10551
• 全文大小：367K
• 年卷期：v.111,no.28(July 19, 2007)
• ISSN：1932-7455

文摘

The structure and thermal stability of differently anchored aromatic self-assembled monolayers (SAMs) ofbenzenethiol (BT) and benzeneselenol (BS) on Au(111) have been studied in-depth by means of thermaldesorption spectroscopy, X-ray photoelectron spectroscopy, near-edge X-ray absorption spectroscopy, andscanning tunneling microscopy. In contrast to long range ordered BS-SAMs consisting of closed packed,upstanding molecules forming a e10001.gif"> structure which resembles the molecular packing of benzene in thecrystalline phase, BT-SAMs are characterized by a loose packing of largely tilted molecules which are arrangedin a e10002.gif"> structure appearing only in small domains. Thermal desorption spectroscopy measurements clearlyshow that BS is less strongly bound to the gold substrate and moreover reveal different desorption peaks foreach SAM, thus indicating the presence of different adsorption states. Heating both SAMs causes initially apartial desorption and formation of a diluted phase where the remaining molecules adopt a nearly flat layingadsorption geometry. The diversity of both molecular films is discussed in terms of the different substrateinteraction of both anchoring groups.