Probing effect of solvation on photoexcited quadrupolar donor-acceptor-donor molecule via ultrafast Raman spectroscopy

Autor: Wei Zhang, Jie Kong, Wenqi Xu, Xinmiao Niu, Di Song, Weimin Liu, Andong Xia
Rok vydání: 2022
Předmět:
Zdroj: Chinese Journal of Chemical Physics. 35:69-76
ISSN: 2327-2244
1674-0068
DOI: 10.1063/1674-0068/cjcp2111223
Popis: The symmetric and quadrupolar donor-acceptor-donor (D-A-D) molecules usually exhibit excited-state charge redistribution process from delocalized intramolecular charge transfer (ICT) state to localized ICT state. Direct observation of such charge redistribution process in real-time has been intensively studied via various ultrafast time-resolved spectroscopies. Femtosecond stimulated Raman spectroscopy (FSRS) is one of the powerful methods which can be used to determine the excited state dynamics by tracking vibrational mode evolution of the specific chemical bonds within molecules. Herein, a molecule, 4,4′-(buta-1,3-diyne-1,4-diyl)bis( N, N-bis(4-methoxyphenyl)aniline), that consists of two central adjacent alkyne (-C≡C-) groups as electron-acceptors and two separated, symmetric N, N-bis(4-methoxyphenyl)aniline at both branches as electron-donors, is chosen to investigate the excited-state photophysical properties. It is shown that the solvation induced excited-state charge redistribution in polar solvents can be probed by using femtosecond stimulated Raman spectroscopy. The results provide a fundamental understanding of photoexcitation induced charge delocalization/localization properties of the symmetric quadrupolar molecules with adjacent vibrational markers located at central position.
Databáze: OpenAIRE