Molecular Dynamics of Excited State Intramolecular Charge Transfer in Solution by Coherent Nuclear Wave Packets. Issue 11 (16th May 2019)

• Record Type: Journal Article
• Authors: Heo, Wooseok; Joo, Taiha
• Is Part Of: Chemphyschem. Volume 20:Issue 11(2019)
• Page Start: 1448
• Page End: 1455
• Publication Date: 2019-05-16
• Subjects: intramolecular charge transfer -- nuclear wave packets -- photochemistry -- reaction coordinates -- time-resolved fluorescence; Chemistry, Physical and theoretical -- Periodicals; 541.05
• DOI: 10.1002/cphc.201801103
• Languages: English
• ISSNs: 1439-4235

Abstract

Abstract: Revealing a proper reaction coordinate in a chemical reaction is the key step towards elucidation of the molecular reaction dynamics. In this report, we investigated the dynamics of intramolecular charge transfer (ICT) of 8‐aminopyrene‐1, 3, 6‐trisulfonic acid (APTS) occurring in the excited state by time‐resolved fluorescence (TF) and TF spectra. Accurate reaction rates and rate‐dependent nuclear wave packets in the product state allow detailed investigation of the molecular reaction dynamics. The ICT rate is solvent dependent: (34 fs) −1, (87 fs) −1, and (∞) −1 in water, formamide, and dimethylformamide, respectively. By recording spectra of the nuclear wave packets for different reaction rates, chemical species responsible for the emission spectra can be positively identified. The origin of the wave packets can be deduced from the amplitude change of the wave packets at different reaction rates, and the vibrational modes that are associated with the reaction coordinate could be identified. Theoretical calculations of the vibrational reorganization energies reproduce the experimental spectrum of the nuclear wave packets and corroborate the conclusions. Abstract : Reaction coordinates : Accurate reaction rates and rate‐dependent nuclear wave packets in the product state allow detailed investigation of the molecular reaction dynamics and identifying reaction coordinates.