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FOC

Code: FOC	Time Slot/Poster Number: 08:30 - 8:50 am	Session: Photophysics and Chemical Dynamics
Ultrafast Vibrational Spectroscopy of Perylene Diimide Complexes
Lynetta Mier¹; Yong Min²; Evgeny O. Danilov¹; Arthur J. Epstein^{1, 2}; Terry L. Gustafson¹
¹Department of Chemistry, The Ohio State University, Columbus, Ohio; ²Department of Physics, The Ohio State University, Columbus, Ohio

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Summary
The ultrafast vibrational dynamics of a series of Perylene Diimine complexes has been studied using time resolved infrared and Raman techniques aiming to retrieve structural details in the process of electron density redistribution upon photoexcitation

Code: FOC	Time Slot/Poster Number: 08:50 - 9:10 am	Session: Photophysics and Chemical Dynamics
Water Assisted and Acid Catalyzed Decarboxylation Reactions of Ketoprofen in Aqueous Solutions
David Lee Phillips¹; Ming-De Li¹; Yong Du³; Jiadan Xue²
¹University of Hong Kong, Hong Kong, Hong Kong; ²Ohio State University, Columbus, Ohio; ³University of Rochester, Rochester, New York

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Summary
In this presentation, nanosecond time-resolved resonance Raman (TR3) spectroscopy was utilized to investigate the photochemistry of ketoprofen in neutral aqueous solutions with varying water concentrations and also in different acidic solutions with varying pH values and kinds of acids.

Code: FOC	Time Slot/Poster Number: 09:10 - 9:30 am	Session: Photophysics and Chemical Dynamics
Photophysics Of Protochlorophyllide
Benjamin Dietzek^{1, 2}; Robert Hanf¹; Michael Schmitt¹; Sonja Seidel¹; Gudrun Hermann¹; Jürgen Popp^{1, 2}
¹Friedrich-Schiller-University Jena, Jena, Germany; ²Institute of Photonic Technology, Jena, Germany

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Summary
This contribution presents a detailed spectroscopic study on the photoinduced excited state dynamics of protochlorophyllide a (PChlide), the substrate of the enzyme protochlorophyllideoxidoreductase. In order to unravel the initial dynamics and its correlation with structural features of the analyte we combine resonance Raman investigations with ultrafast solvent-dependent transient absorption and transient anisotropy measurements. Combining Raman spectroscopy with DFT calculations, the modes observed in the coherent wavepacket can be assigned to low wavenumber motions of a cyclopentanonering, which is the prominent structural feature of the molecule and impacts the photophysics of the molecule over several orders in time.

Code: FOC	Time Slot/Poster Number: 09:30 - 9:50 am	Session: Photophysics and Chemical Dynamics
Photodissociation Dynamics of Acetone in the Gas Phase and in Solution Studied by Transient Absorption and Femtosecond Stimulated Raman Spectroscopy
Seung Min Jin; Hye Ran Koh; Ilseung Yang; Junhee Kang; Hyung Min Kim; Seong Keun Kim
Seoul National University, Seoul, South Korea

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Summary
Photodissociation dynamics of acetone was investigated for the first time in the gas phase and also in solution by transient absorption and femtosecond stimulated Raman spectrscopy. In the gas phase, a Rydberg state with a decay time of 350 fs, which in solution decays at ~ 100 fs. In solution. we also found evidence for solvated electron generation. Vibrational information about the photodissociation dynamics was investigated in the gas phase by femtosecond stimulated Raman spectroscopy. Vibrational peaks for the nR state were observed at 1835 cm-1 for C=O stretching and at 3100 cm-1 for C-H stretching.

Code: FOC	Time Slot/Poster Number: 09:50 - 10:10 am	Session: Photophysics and Chemical Dynamics
Molecular Near-Field Effect in Resonance Hyper-Raman Scattering: Excitation Profile of All-Trans-Beta-Carotene in Cyclohexane
Rintaro Shimada¹; Hiro-o Hamaguchi^{1, 2}
¹School of Science, the University of Tokyo, Tokyo, Japan; ²National Chiao Tung University, Hsinchu, Taiwan

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Summary
"Molecular near-field effect" is a new resonance phenomenon of hyper-Raman scattering that we discovered recently, in which solvent hyper-Raman bands gain their intensity by more than 5 orders of magnitude when all-trans-beta-carotene are present in the vicinity. We have proposed an extended vibronic theory, which explicitly incorporates intermolecular vibronic coupling between excited electronic states of the solute and vibrations of the neighboring solvent and accounted for the observed enhancement. In the present paper, we report resonance hyper-Raman excitation profiles of the enhanced solvent bands together with those of beta-carotene and discuss the mechanism of the newly found resonance effect.

Code: FOC	Time Slot/Poster Number: 10:10 - 10:30 am	Session: Photophysics and Chemical Dynamics
Understanding the Ground- and Excited-State Photophysics of Oxadiazole and Triarylamine Substituents in Copper and Rhenium Metal Complexes
Raphael Horvath¹; Michael Fraser¹; Pawel Wagner²; David Officer²; Keith Gordon¹
¹University of Otago, Dunedin, New Zealand; ²University of Wollongong, Wollongong, Australia

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Summary
Ground- and excited-state resonance Raman techniques were used to examine a series of copper and rhenium complexes containing oxadiazole and triarylamine groups. Their electronic transitions have been identified and excited-state behaviors elucidated in conjunction with density functional theory calculations as well as transient emission and absorption experiments. It is found that the complexes containing triarylamine groups exhibit strong charge transfer transitions at ca. 450 nm.