Molecular Spectroscopy Laboratory, RIKEN

报告人简介：

Tahei Tahara graduated and obtained his Ph.D. from the University of Tokyo in 1984 and 1989. After being a research associate at the University of Tokyo in 1989 and at Kanagawa Academy of Science and Technology in 1990, he joined the Institute for Molecular Science (IMS) as an associate professor and started his own research group in 1995. He moved to RIKEN as a chief scientist in 2001 and has been the director of the Molecular Spectroscopy Laboratory since then. His research interests are ultrafast spectroscopy, nonlinear spectroscopy, and single-molecule spectroscopy of complex molecular systems.

报告摘要：

Liquid interfaces provide unique environments where various important chemical/physical processes occur. Heterodyne-detected vibrational sum-frequency generation (HD-VSFG) directly measures the phase and amplitude of the 2nd-order nonlinear optical signal generated only from the interface region of a few monolayer thicknesses. Therefore, time-resolved HD-VSFG provides interface-selective time-resolved vibrational spectra interpreted as the spectral change induced by photoexcitation.

We realized that femtosecond IR-excited and UV-excited time-resolved HD-VSFG were used to observe ultrafast processes directly proceeding at the water interfaces. We recently clarified the vibrational relaxation mechanism of free OH and obtained an overall picture of the vibrational relaxation process of the OH stretch at the air/water interface. Furthermore, we successfully tracked a drastically accelerated photochemical phenol reaction at the water surface. These studies on phenol photochemistry indicated the generality of the significant difference in reaction dynamics between the interface and bulk.

邀请人：翁羽翔（8264 8118）

联系人：胡颖（8264 9361）