XII Iberian Meeting of Electrochemistry XVI Meeting of the ...

XII Iberian Meeting of Electrochemistry & XVI Meeting of the Portuguese Electrochemical Society PC 03
Formation of mixed self-assembled monolayers of mono- and
dithiols on Au(111)
Rafael C. González-Cano, Rafael Madueño, Manuel Blázquez, Teresa Pineda
Dpto. Química Física y Termodinámica Aplicada, Universidad de Córdoba, Córdoba, SPAIN
tpineda@uco.es
Alkanedithiolate self-assembled monolayers (SAMs) can form on Au(111) singlecrystal
electrodes by the spontaneous formation of a strong gold-sulfur bond with one of
the SH terminal groups and the attractive van der Waals forces between adjacent alkyl
chains. The control of the organization of these architectures is of great technological
importance, and the formation of well-organized layers is needed. In these layers, the
second unreacted thiol moieties should
be exposed to the outer surface [1,2].
To obtain compact dithiol layers of
standing-up molecules, the use of a
mixture of monothiol and dithiol
derivatives at the appropriate relative
concentrations that results in an
almost pure dithiol film, have been
reported [3]. In this work, we report
on the formation of a mixed layer of
octanedithiol (ODT) and octanethiol
(OT). The formation process is carried
out under electrochemical control.
Thus, an exploration of the different
experimental conditions of ODT/OT
molar ratio, electrochemical
deposition potential and deposition
time is described.
Figure 1. Cyclic voltammograms for the oxidative deposition of ODT and OT layer in
0.1 M NaOH solution on Au(111) single crystal electrode.
In Figure 1, the oxidative deposition of ODT and OT in alkaline solutions are shown. It
can be deduced that the different peak potentials will drive the formation of a mixed
layer depending on the ratio of molecules employed.
Acknowledgments: Project CTQ2007/62723, Junta de Andalucía and Universidad de Córdoba.
References
[1] García Raya, D.; Madueño, R.; Sevilla, J.M.; Blázquez, M.; Pineda, T.; Electrochim. Acta,
2008, 53, 8026.
[2] García Raya, D.; Madueño, R.; Blázquez, M.; Pineda, T.; J. Phys. Chem. C, 2010, 114, 3568.
[3] Jiang, W. R.; Zhitenev, N.; Bao, Z. N.; Meng, H.; Abusch-Magder, D.; Tennant, D.; Garfunkel,
E. Langmuir 2005, 21, 8751.
September, 811, 2010. ISEL - Lisbon 81