Prevention of surface reconstruction at the Au(110)/electrolyte interface by the adsorption of cytosine.
It is shown that the adsorption of cytosine at the Au(110)/liquid interface at a potential of 0.0 V "freezes" the Au(110) surface in the (1x1) structure and that the molecule does not change its orientation on the surface as the potential is varied. In contrast the adsorption of adenine does not freeze the Au(110) surface even though both molecules adopt a base stacking structure with individual molecules oriented in a plane vertical to the Au(110) surface with their long axes along [110] rows. It is suggested that cytosine bonds to three Au atoms through the NH(2) group, the N(3) and O(8) sites, and that this arrangement stabilizes the Au(110) surface and prevents its reconstruction to the more open (1x2) and (1x3) structures as the applied voltage is varied. The weaker bonding of the adenine molecule with the gold surface is unable to prevent the voltage induced reconstruction of the Au(110) surface.
Department of Physics, Oliver Lodge Laboratory, University of Liverpool, Liverpool L69 7ZE, United Kingdom.
C P
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Mansley
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Smith
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Bowfield
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Fernig
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Edwards
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Weightman
D000327:Adsorption; D003596:Cytosine / Q000737:chemistry*; D004573:Electrolytes / Q000737:chemistry; D006046:Gold / Q000737:chemistry*; D013499:Surface Properties
D004573:Electrolytes; D006046:Gold; D003596:Cytosine