Imidazole-based excited-state intramolecular proton-transfer (ESIPT) materials: observation of thermally activated delayed fluorescence (TDF) |
| |
Authors: | Park Sanghyuk Kwon Oh-Hoon Lee Young-Shin Jang Du-Jeon Park Soo Young |
| |
Institution: | Department of Materials Science and Engineering, Seoul National University, ENG 445, Seoul 151-744, Korea. |
| |
Abstract: | We report the first observation of thermally activated delayed fluorescence (TDF) from an excited-state intramolecular proton-transfer (ESIPT) molecule, a hydroxyl-substituted tetraphenyl imidazole derivative (HPI-Ac), in degassed solutions as well as in low-temperature organic matrixes. In the absence of oxygen, the blue emission of an identical spectral feature was observed in the nanosecond ( approximately 4.4 ns) and microsecond ( approximately 25 micros) time domains, and the fluorescence intensity increased with temperature. From the temperature dependence of the time-resolved spectra of HPI-Ac, the energy gap between the first-excited singlet state and the lowest triplet state was determined to be 7.6 +/- 0.3 kJ/mol (630 +/- 25 cm-1), and the limiting rate constant of intrinsic reverse intersystem crossing was estimated to be 1.3 (+/-0.5) x 107 s-1. |
| |
Keywords: | |
本文献已被 PubMed 等数据库收录! |
|