Article ID Journal Published Year Pages File Type
220458 Journal of Electroanalytical Chemistry 2008 8 Pages PDF
Abstract

Standard vibrational sum-frequency generation (SFG) spectroscopy is performed to probe the electrochemical cyanoacetylene/Au(1 1 1) interface, enlightening a 20 cm−1/V Stark shift of the free CN vibration mode of this cyanopolyynes-class molecule. SFG data suggest an orientation for the adsorbed molecules with the CN moiety pointing out in a direction perpendicular to the metal surface. A newly developed two-colour SFG (2C-SFG) set-up based on the CLIO free electron laser synchronized with a tuneable visible laser source is used to probe simultaneously the vibrational and electronic fingerprint of a thiophenol/Ag(1 1 1) interface. Structural information on the adsorbed self-assembled monolayer is put in evidence as a function of the immersion time of the silver substrate in the thiophenol solution (24 h or 5 days). With a longer immersion time, the molecular packing is of better quality and more compact, with the carbon rings less tilted with respect to the surface normal. This new experimental set-up combines the advantages to have a higher spectral and temporal resolution with higher power energies at far infrared wavelengths than these presently available from tabletop infrared optical parametric oscillators.

Related Topics
Physical Sciences and Engineering Chemical Engineering Chemical Engineering (General)
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