This Week in Chemistry

Thursday 14th February 2013

Departmental Seminar

Nonlinear Optical Spectroscopy of Interfaces

Speaker: Dr. Heike Arnolds, Surface Science Research Centre, Department of Chemistry, University of Liverpool.

Vibrational spectroscopy is powerful because intrinsic vibrations of the sample under study provide us with chemical information. It is a challenge to study specifically molecules at an interface, as IR and Raman have limited surface sensitivity, and the response of a minor portion of interfacial molecules may be obscured by the bulk response on either side of the interface. In vibrational Sum Frequency Generation (SFG), two short laser pulses, one in the IR, one in the visible, meet at the interface, which causes emission of light at the sum frequency. The optical selection rules suppress the signal from the isotropic bulk, making it inherently sensitive to the interface and allow determination of the absolute orientation of molecules at interfaces. Additionally, the use of femtosecond laser pulses permits simultaneous time and frequency resolution in order to follow molecular dynamics at interfaces in real time. In this talk I will give an overview of SFG for the study of molecular adsorption and dynamics at interfaces.
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12.00 pm, Chemistry Department, Lecture Theatre 6