Affiliation:
1. College of Chemistry and Molecular Engineering, Beijing National Laboratory for Molecular Sciences Peking University Beijing 100871 China
Abstract
AbstractVibrational‐mode‐selective modulation of electronic excitation is conducted with a synchronized femtosecond (fs) visible (vis) pulse and a picosecond (ps) infrared (IR) pulse. The mechanism of modulation of vibrational and vibronic relaxation behavior of excited state is investigated with ultrafast vis/IR, IR/IR, and vis‐IR/IR transient spectroscopy, optical gating experiments and theoretical calculations. An organic molecule, 4′‐(N,N‐dimethylamino)‐3‐methoxyflavone (DMA3MHF) is chosen as the model system. Upon 1608 cm−1 excitation, the skeleton stretching vibration of DMA3MHF is energized, which can significantly change the shape of the absorption, facilitate the radiative decay and promote emission from vibrational excited states. As results, a remarkable enhancement and a slight blueshift in fluorescence are observed. The mode‐selective modulation of electronic excitation is not limited in luminescence or photophysics. It is expected to be widely applicable in tuning many photochemical processes.
Funder
National Natural Science Foundation of China
Peking University