TADF and X-ray Radioluminescence of New Cu(I) Halide Complexes: Different Halide Effects on These Processes
oleh: Alexander V. Artem'ev, Andrey Yu. Baranov, Alexey S. Berezin, Dmitry V. Stass, Christina Hettstedt, Ul’yana A. Kuzmina, Konstantin Karaghiosoff, Irina Yu. Bagryanskaya
| Format: | Article |
|---|---|
| Diterbitkan: | MDPI AG 2023-03-01 |
Deskripsi
A series of complexes [Cu<sub>2</sub>X<sub>2</sub>(Pic<sub>3</sub>PO)<sub>2</sub>] (X = Cl, Br, I) based on tris(pyridin-2-ylmethyl)phosphine oxide (Pic<sub>3</sub>PO) has been synthesized. At 298 K, these compounds exhibit thermally activated delayed fluorescence (TADF) of <sup>1</sup>(M+X)LCT type with λ<sub>max</sub> varying from 485 to 545 nm, and quantum efficiency up to 54%. In the TADF process, the halide effect appears as the emission intensification and bathochromic shift of λ<sub>max</sub> in the following order X = I < Br < Cl. Upon X-ray irradiation, the title compounds emit radioluminescence, the emission bands of which have the same shape as those at TADF, thereby meaning a similar radiative excited state. By contrast to TADF, the halide effect in the radioluminescence is reversed: its intensity grows in the order X = Cl < Br < I, since heavier atoms absorb X-rays more efficiently. These findings essentially contribute to our knowledge about the halide effect in the photo- and radioluminescent Cu(I) halide emitters.