Reaction dynamics by time-resolved wave packet spectroscopies & molecular dynamics simulation

• Main Authors: Heo, Wooseok, Kim, JunWoo, Lee, Changmin, Joo, Taiha
• Other Authors: Asian Spectroscopy Conference 2020
• Format: Conference or Workshop Item
• Language: English
• Published: 2020
• Subjects: Science::Chemistry; Nuclear Wave Packets; Molecular Dynamics Simulation
• Online Access: https://hdl.handle.net/10356/144279
• Institution: Nanyang Technological University

Recent advances in short pulse lasers and time domain spectroscopies enabled investigation of molecular dynamics in a few femtosecond and even attosecond regime. For a coherent photochemical reaction occurring in an electronic excited state, molecular reaction dynamics can be studied by recording the nuclear wave packet motions in the reactant and product potential energy surfaces (PES) following photoexcitation to a Franck-Condon state. [1-4] Wave packets in the product state may also be formed by an impulsive chemical reaction. Evolution of the wave packets may contain extensive information on the PES and reaction coordinates. Time-domain experiments such as pump-probe transient absorption (TA) and time-resolved fluorescence (TF) with high enough time resolution can record nuclear wave packet motions spanning a full vibrational spectrum up to 3000 cm−1. We have developed experimental methods to record the wave packets and a theoretical method based on a molecular dynamics simulation to analyze the wave packet motion of each vibrational mode following photoexcitation. In this presentation, we show the method and application examples.