Chemisorption of Self Assembled Alkyl Thiol on Au(111)

1994 ◽  
Vol 366 ◽  
Author(s):  
M. S. Yeganeh ◽  
S. M. Dougal ◽  
R. S. Polizzotti ◽  
P. Rabinowitz
Keyword(s):  
Azimuthal Angle ◽  
Sum Frequency Generation ◽  
Interfacial Structure ◽  
Single Type ◽  
Gold Substrate ◽  
Self Assembled Monolayer ◽  
Sum Frequency ◽  
Self Assembled ◽  
Frequency Generation

ABSTRACTWe have used infrared-visible sum-frequency generation (SFG) to spectroscopically probe the interfacial structure of a self assembled monolayer (SAM) of alkyl thiol on a Au(111) surface. The SFG spectra of the CH3 group measured as a function of azimuthal angle indicates that sulfur atoms cannot be situated at sites of a single type, e.g., hollow or bridge, but must be in a mixed arrangement. SFG is also used to study the reconstruction of the gold substrate by alkyl thiol.

scholarly journals Sum frequency generation spectroscopy probing of formation of self-assembled monolayers from thiols with terminal phenylalanine ring and intrachain amide groups

Chemija ◽  
2018 ◽  
Vol 29 (4) ◽  
Author(s):  
Marija Špandyreva ◽  
Ilja Ignatjev ◽  
Ieva Matulaitienė ◽  
Zenonas Kuodis ◽  
Gediminas Niaura
Keyword(s):  
Low Frequency ◽  
Sum Frequency Generation ◽  
Self Assembled Monolayer ◽  
Sum Frequency ◽  
Sum Frequency Generation Spectroscopy ◽  
Assembled Monolayers ◽  
Stretching Vibration ◽  
Polycrystalline Gold ◽  
Self Assembled ◽  
Frequency Generation

Formation of a self-assembled monolayer onto the polycrystalline gold substrate from thiols containing a terminal phenylalanine (Phe) ring and intrachain amide groups (HS-(CH2)7-CONH-(CH2)2-C6H5) was characterized by vibrational sum frequency generation (SFG) spectroscopy. The temporal evolution of the characteristic Phe ring stretching vibration ν(=C–H) near 3069 cm–1 and the Amide A mode were monitored by nonlinear vibrational spectroscopy. The SFG data revealed the complete ordering of the terminal Phe rings after about 60 min of adsorption. Formation of a strong hydrogen bonding between the adjacent chains of adsorbed molecules was evident by appearance of the Amide A mode at the relative low frequency (3280–3308 cm–1). The well-ordered and strongly hydrogen bonded SAM with the terminal Phe ring functionality is a promising platform for the analysis of interactions and the function of aromatic rings in biomolecular processes.

Bulk Contributions Modulate the Sum-Frequency Generation Spectra of Interfacial Water on Model Sea-Spray Aerosols

2018 ◽  
Author(s):  
Sandeep K. Reddy ◽  
Raphael Thiraux ◽  
Bethany A. Wellen Rudd ◽  
Lu Lin ◽  
Tehseen Adel ◽  
...  
Keyword(s):  
Single Layer ◽  
Sum Frequency Generation ◽  
Second Order ◽  
Interfacial Structure ◽  
Sea Spray ◽  
Third Order ◽  
Systematic Analysis ◽  
Sum Frequency ◽  
Structure Of Water ◽  
Frequency Generation

Vibrational sum-frequency generation (vSFG) spectroscopy is used to determine the molecular structure of water at the interface of palmitic acid monolayers. Both measured and calculated spectra display speci c features due to third-order contributions to the vSFG response which are associated with nite interfacial electric potentials. We demonstrate that theoretical modeling enables to separate the third-order contributions, thus allowing for a systematic analysis of the strictly surface-sensitive, second-order component of the vSFG response. This study provides fundamental, molecular-level insights into the interfacial structure of water in a neutral surfactant system with relevance to single layer bio-membranes and environmentally relevant sea-spray aerosols. These results emphasize the key role that computer simulations can play in interpreting vSFG spectra and revealing microscopic details of water at complex interfaces, which can be difficult to extract from experiments due to the mixing of second-order, surface-sensitive and third-order, bulk-dependent contributions to the vSFG response.

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