Constructing Gold-Thiolate Oligomers and Polymers on Au(111) Based on the Linear S-Au-S Geometry

Journal Article · Thu Jan 01 04:00:00 EST 2009 · Journal of Physical Chemistry C

OSTI ID:1044679

Dai, Sheng ^[1]; Jiang, Deen ^[1]

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1. ORNL

Although neat gold-thiolate oligomers and polymers made of linear S-Au-S bonds have been well-known, observation of RS-Au-SR linear complexes (RS- being an alkylthiolate group) on Au(111) has been reported only recently. On the basis of the unique geometry and bonding of the RS-Au-SR complex on Au(111), we construct simple geometric models of Au-SR oligomers and polymers on Au(111) by fusing linear S-Au-S units matched to the underlying Au(111) surface lattice. We then optimize these models by density functional theory. The hexagonal geometry of the Au(111) lattice determines three possible angles (60{sup o}, 120{sup o}, and 180{sup o}) for connecting two linear S-Au-S units, which lead to isomerism of the Au-SR oligomers and polymer on Au(111). Here we explore open dimers, trimers, and tetramers and cyclic trimers, tetramers, and hexamers of the Au-SR oligomers on Au(111). We also examine four isomers of the Au-SR polymer on Au(111). We find that the 120{sup o} Au-S-Au angle is preferred in constructing both oligomeric and polymeric isomers. The two polymeric isomers with 120{sup o} Au-S-Au angles are found to be energetically competitive with a previous model proposed for the Au-SR polymer on Au(111). We also discuss potential ways to create Au-SR oligomers on Au(111).

• Research Organization: Oak Ridge National Laboratory (ORNL)
• Sponsoring Organization: SC USDOE - Office of Science (SC)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 1044679
• Journal Information: Journal of Physical Chemistry C, Journal Name: Journal of Physical Chemistry C Journal Issue: 18 Vol. 113; ISSN 1932-7447
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
BONDING
DIMERS
FUNCTIONALS
GEOMETRY
ISOMERS
POLYMERS