Code: MOG	Time Slot/Poster Number: 4:00 - 4:30 pm	Session: Time Resolved Raman
Primary Protein Responses to Chromophore Isomerization of Photosensary Proteins
Yasuhisa Mizutani; Misao Mizuno
Osaka University, Toyonaka, Osaka, Japan
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Summary
Photoactive yellow protein (PYP) is a blue-light sensor considered to be responsible for the light-induced negative phototaxis of bacteria. It possesses the PAS domain structural motif, which is widely involved in a number of sensory proteins, and thus serves as a useful structural prototype for the PAS super-family as well as a good model for understanding the signal transduction of sensory proteins. In this talk, we will discuss the ultrafast structural dynamics of aromatic amino acid residues in PYP using picosecond time-resolved ultraviolet resonance Raman spectroscopy.

Code: MOG	Time Slot/Poster Number: 4:30 - 5:00 pm	Session: Time Resolved Raman
New Attempts with Raman Spectroscopy for Examining Macromolecules and Lipid Bilayer Membranes
Koichi Iwata
Gakushuin University, Toshima, Tokyo , Japan
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Summary
We report on two new attempts for examining the structure and characteristics of macromolecules and molecular assemblies. We develop a low-frequency multichannel Raman microspectrometer that covers the spectral range down to 20 cm-1 with a new notch filter. A grating is formed in the filter glass itself. We measure the cooling kinetics of S1 trans-stilbene solubilized in a lipid bilayer of egg-PC liposome. The cooling rate observed in the liposome bilayer was faster than the rates recorded for ordinary alkanes. The disagreement is probably caused by the presence of water which has a markedly large thermal diffusivity.

Code: MOG	Time Slot/Poster Number: 5:00 - 5:30 pm	Session: Time Resolved Raman
The ULTRA Laser System - For Time-Resolved Spectroscopy
Anthony Parker
Central Laser Facility, Didcot, United Kingdom
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Summary
Time-resolved vibrational spectroscopy (TRVS) has many unique features and capabilities for elucidating the structural changes of transient species across the fs to ms time frame. The recently developed 10 KHz, 10W ULTRA laser system represents the very latest technology. ULTRA's performance and capabilities will be described for the time resolved infrared, 2D infrared and femtosecond stimulated Raman spectroscopy techniques with examples taken from organometallic intermediates, organic excited states and DNA tertiary structure.

Code: MOG	Time Slot/Poster Number: 5:30 - 5:50 pm	Session: Time Resolved Raman
Singlet fission and triplet dynamics in carotenoid aggregates probed with picosecond resonance Raman spectroscopy
Michael Tauber; Chen Wang
University of California, San Diego, La Jolla, CA
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Summary
We report the first finding of singlet fission in a self-assembled organic molecular aggregate. The aggregates consist of natural carotenoids. Our use of picosecond resonance Raman spectroscopy was crucial in the discovery of >100% triplet yield per absorbed photon, which is proof of a singlet fission mechanism for triplet generation. The triplet yield depends on aggregate structure, and is hundreds of times greater than found for monomeric carotenoids. The findings have general implications for the mechanism of singlet fission, and the possibility of utilizing this photophysical process in new methods of solar energy conversion.

Code: MOG	Time Slot/Poster Number: 5:50 - 6:10 pm	Session: Time Resolved Raman
The Vibrational Pumping Mechanism in Surface Enhanced Raman Scattering – a sub Picosecond Time Resolved Study
Wolfgang Werncke; Valeri Kozich
Max-Born-Institut, Berlin, Germany
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Summary
Vibrational pumping in surface enhanced Raman scattering is investigated applying sub-picosecond Raman spectroscopy. We observe selective excitation of distinct fingerprint modes resulting in a pronounced non-equilibrium population distribution followed by a decay with a 1 ps time constant. In particular, a Raman-active mode with the highest frequency becomes strongly excited. Vibrational excitation is delayed with respect to the excitation pulses. Our findings clearly rule out Stokes Raman scattering, but indicate electronic excitation as the main source of vibrational pumping. After electronic excitation energy is transferred to the vibrations by fluorescence and ultrafast internal conversion within about 0.8 ps.