These are preliminary reports that have not been peer-reviewed. They should not be regarded as conclusive, guide clinical practice/health-related behavior, or be reported in news media as established information. For more information, please see our FAQs.
Characterization of Excited States in a Multiple-Resonance-Type Thermally Activated Delayed Fluorescence Molecule Using Time-resolved Infrared Spectroscopy
preprintsubmitted on 07.02.2021, 07:15 and posted on 08.02.2021, 12:37 by Yuushi Shimoda, Masaki Saigo, Tomohiro Ryu, Takumi Ehara, Kiyoshi Miyata, Ken Onda
We have investigated the correlation between the photophysical properties and the excited-state detailed characteristics in a multiple-resonance-type thermally activated delayed fluorescence (TADF) molecule, DABNA-1, using time-resolved infrared vibrational spectroscopy. In comparison of the distinctive vibrational spectra in the fingerprint region, 1000 - 1700 cm-1, to the simulated spectra by density functional theory calculations, we found the best calculation condition. On the basis of the calculations, we determined the excited-state geometries and molecular orbitals of the lowest excited singlet (S1) and triplet (T1) states as well as the ground state (S0). We revealed that the similarity of the potential surfaces between T1 and S0 suppresses the nonradiative decay and causes the high fluorescence quantum yield via TADF process.