PATRITO EDUARDO MARTÍN
Congresos y reuniones científicas
Título:
Structure and Stability of a,w-alkanedithiols Adlayers on Au(111): An Electrochemical Study
Autor/es:
F. P. COMETTO; C. A. CALDERÓN; E. M. EUTI; D. K. JACQUELÍN; M. A. PEREZ; E. M. PATRITO; V. A. MACAGNO
Lugar:
Florianopolis
Reunión:
Congreso; 10th Intl. Symposium on Passivity of Metals and Semiconductors; 2011
Institución organizadora:
Internaternational Society of Electrochemistry
Resumen:
Structure and stability of self-assembled adlayers of alkanedithiols (DTs) were studied
with electrochemical techniques: reductive desorption experiments, redox couples cyclic
voltamperometry and electrochemical impedance spectroscopy. Adlayers for DTs with
different number of carbon atoms in the chain length (2-9) were formed in solvents with
different polarity (ethanol, n-hexane and toluene), by controlling the O2 levels, and by using a
post-deposition treatment with mild reducing agents to investigate the role played by the
disulphide bond (S-S) formation (whether interlayer or intralayer) in determining the final
structure and stability1-2. Multilayer is the most favored structure for adlayers of short chain
length DTs (ethanedithiol) when formed by dipping in solutions with solvents of high polarity
(ethanol). As the chain length increases, the multilayer structure is not observed although
intralayer formation of S-S bonds is detected. DTs adlayers with a monolayer structure are
easily obtained by using low polarity solvents in the dipping solution. The treatment of
adlayers with mild reducing agents proved to be a very effective procedure to transform
multilayers into monolayers as well as to re-activate the adlayer ending groups by reduction
of the S-S bonds. Adlayers formed in toluene dipping solutions exhibit DTs molecules in a
lying-down or U-loop structures.
FIGURE: C-1 vs. number of carbons in the DTs’ chain length for adlayers formed in ethanol, n-hexane and toluene as to compared to the references of monothiols SAMs and alkanedithiols in a Uloop configuration.
References
1 M. L. Carot, M. J. Esplandiu, F. P. Cometto, E. M. Patrito, V. A. Macagno; J. Electroanal. Chem. 579 (2005)
13.
2 T. Y. B. Leung, M. C. Gerstenberg, D. J. Lavrich, G. Scoles, F. Schreiber, G. E. Poirier; Langmuir 16 (2000)
549.
with electrochemical techniques: reductive desorption experiments, redox couples cyclic
voltamperometry and electrochemical impedance spectroscopy. Adlayers for DTs with
different number of carbon atoms in the chain length (2-9) were formed in solvents with
different polarity (ethanol, n-hexane and toluene), by controlling the O2 levels, and by using a
post-deposition treatment with mild reducing agents to investigate the role played by the
disulphide bond (S-S) formation (whether interlayer or intralayer) in determining the final
structure and stability1-2. Multilayer is the most favored structure for adlayers of short chain
length DTs (ethanedithiol) when formed by dipping in solutions with solvents of high polarity
(ethanol). As the chain length increases, the multilayer structure is not observed although
intralayer formation of S-S bonds is detected. DTs adlayers with a monolayer structure are
easily obtained by using low polarity solvents in the dipping solution. The treatment of
adlayers with mild reducing agents proved to be a very effective procedure to transform
multilayers into monolayers as well as to re-activate the adlayer ending groups by reduction
of the S-S bonds. Adlayers formed in toluene dipping solutions exhibit DTs molecules in a
lying-down or U-loop structures.
FIGURE: C-1 vs. number of carbons in the DTs’ chain length for adlayers formed in ethanol, n-hexane and toluene as to compared to the references of monothiols SAMs and alkanedithiols in a Uloop configuration.
References
1 M. L. Carot, M. J. Esplandiu, F. P. Cometto, E. M. Patrito, V. A. Macagno; J. Electroanal. Chem. 579 (2005)
13.
2 T. Y. B. Leung, M. C. Gerstenberg, D. J. Lavrich, G. Scoles, F. Schreiber, G. E. Poirier; Langmuir 16 (2000)
549.
