New insight into the electrochemical desorption of alkanethiol SAMs on gold
A combination of Polarization Modulation Infrared Reflection Absorption Spectroscopy (PMIRRAS) under electrochemical control, Electrochemical Scanning Tunneling Microscopy (ECSTM) and Molecular Dynamics (MD) simulations has been used to shed light on the reductive desorption process of dodecanethiol...
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todo:paper_14639076_v14_n35_p12355_Pensa2023-10-03T16:16:48Z New insight into the electrochemical desorption of alkanethiol SAMs on gold Pensa, E. Vericat, C. Grumelli, D. Salvarezza, R.C. Park, S.H. Longo, G.S. Szleifer, I. Méndez De Leo, L.P. alkane gold thiol derivative water adsorption article chemistry electrochemical analysis molecular dynamics surface property Adsorption Alkanes Electrochemical Techniques Gold Molecular Dynamics Simulation Sulfhydryl Compounds Surface Properties Water A combination of Polarization Modulation Infrared Reflection Absorption Spectroscopy (PMIRRAS) under electrochemical control, Electrochemical Scanning Tunneling Microscopy (ECSTM) and Molecular Dynamics (MD) simulations has been used to shed light on the reductive desorption process of dodecanethiol (C12) and octadecanethiol (C18) SAMs on gold in aqueous electrolytes. Experimental PMIRRAS, ECSTM and MD simulations data for C12 desorption are consistent with formation of randomly distributed micellar aggregates stabilized by Na + ions, coexisting with a lying-down phase of molecules. The analysis of pit and Au island coverage before and after desorption is consistent with the thiolate-Au adatoms models. On the other hand, PMIRRAS and MD data for C18 indicate that the desorbed alkanethiolates adopt a Na+ ion-stabilized bilayer of interdigitated alkanethiolates, with no evidence of lying down molecules. MD simulations also show that both the degree of order and tilt angle of the desorbed alkanethiolates change with the surface charge on the metal, going from bilayers to micelles. These results demonstrate the complexity of the alkanethiol desorption in the presence of water and the fact that chain length and counterions play a key role in a complex structure. © This journal is the Owner Societies 2012. Fil:Grumelli, D. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Méndez De Leo, L.P. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_14639076_v14_n35_p12355_Pensa |
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Universidad de Buenos Aires |
| institution_str |
I-28 |
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R-134 |
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Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
alkane gold thiol derivative water adsorption article chemistry electrochemical analysis molecular dynamics surface property Adsorption Alkanes Electrochemical Techniques Gold Molecular Dynamics Simulation Sulfhydryl Compounds Surface Properties Water |
| spellingShingle |
alkane gold thiol derivative water adsorption article chemistry electrochemical analysis molecular dynamics surface property Adsorption Alkanes Electrochemical Techniques Gold Molecular Dynamics Simulation Sulfhydryl Compounds Surface Properties Water Pensa, E. Vericat, C. Grumelli, D. Salvarezza, R.C. Park, S.H. Longo, G.S. Szleifer, I. Méndez De Leo, L.P. New insight into the electrochemical desorption of alkanethiol SAMs on gold |
| topic_facet |
alkane gold thiol derivative water adsorption article chemistry electrochemical analysis molecular dynamics surface property Adsorption Alkanes Electrochemical Techniques Gold Molecular Dynamics Simulation Sulfhydryl Compounds Surface Properties Water |
| description |
A combination of Polarization Modulation Infrared Reflection Absorption Spectroscopy (PMIRRAS) under electrochemical control, Electrochemical Scanning Tunneling Microscopy (ECSTM) and Molecular Dynamics (MD) simulations has been used to shed light on the reductive desorption process of dodecanethiol (C12) and octadecanethiol (C18) SAMs on gold in aqueous electrolytes. Experimental PMIRRAS, ECSTM and MD simulations data for C12 desorption are consistent with formation of randomly distributed micellar aggregates stabilized by Na + ions, coexisting with a lying-down phase of molecules. The analysis of pit and Au island coverage before and after desorption is consistent with the thiolate-Au adatoms models. On the other hand, PMIRRAS and MD data for C18 indicate that the desorbed alkanethiolates adopt a Na+ ion-stabilized bilayer of interdigitated alkanethiolates, with no evidence of lying down molecules. MD simulations also show that both the degree of order and tilt angle of the desorbed alkanethiolates change with the surface charge on the metal, going from bilayers to micelles. These results demonstrate the complexity of the alkanethiol desorption in the presence of water and the fact that chain length and counterions play a key role in a complex structure. © This journal is the Owner Societies 2012. |
| format |
JOUR |
| author |
Pensa, E. Vericat, C. Grumelli, D. Salvarezza, R.C. Park, S.H. Longo, G.S. Szleifer, I. Méndez De Leo, L.P. |
| author_facet |
Pensa, E. Vericat, C. Grumelli, D. Salvarezza, R.C. Park, S.H. Longo, G.S. Szleifer, I. Méndez De Leo, L.P. |
| author_sort |
Pensa, E. |
| title |
New insight into the electrochemical desorption of alkanethiol SAMs on gold |
| title_short |
New insight into the electrochemical desorption of alkanethiol SAMs on gold |
| title_full |
New insight into the electrochemical desorption of alkanethiol SAMs on gold |
| title_fullStr |
New insight into the electrochemical desorption of alkanethiol SAMs on gold |
| title_full_unstemmed |
New insight into the electrochemical desorption of alkanethiol SAMs on gold |
| title_sort |
new insight into the electrochemical desorption of alkanethiol sams on gold |
| url |
http://hdl.handle.net/20.500.12110/paper_14639076_v14_n35_p12355_Pensa |
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