講演情報
[15p-P04-2]Benchmark molecular design strategy to achieve dual enhancement of record high two-photon absorption cross-section with TADF character
〇(D)GomathiVinayakam Mageswari1, Youhei Chitose1, Ja-Hon Lin2, Youichi Tsuchiya1, Chihaya Adachi1 (1.Kyushu Univ, 2.Nati Taipei Univ Tec)
キーワード：
TADF、Two photon absorption
In this study, we devise a systematic molecular design for the dual character of record high two-photon absorption (2PA) with a thermally activated delayed fluorescence (TADF) emitter by the concurrent achievement of a small singlet-triplet energy gap (ΔEST) and a large oscillator strength (f).[1] The interconnection between chemical design and photophysical character is crucial for developing fluorophores in optoelectronic applications. Herein, we designed a novel TBPZ2TPA composed of a tetrabenzo[a,c] phenazine (TBPZ) unit as a planar acceptor and a triphenylamine (TPA) unit as a donor.[2] TADF material, having an emission property of λ max = 575 nm and 71 % photoluminescence quantum yields (PLQY), demonstrates strong nonlinear optical absorption. The integrated effects of rigid planar acceptor influence and moderate steric hindrance between D and A units endow high molecular rigidity that suppresses nonradiative decay with improved PLQYs. Specifically, the well-aligned excited states involve a singlet and a triplet charge transfer excited states. The combined effect balances the TADF phenomenon by a small ΔEST and maintains a high 2PA cross-section with a large f value. (Fig. 1). Moreover, the fused molecular design exhibits a quadrupolar structure with a rigid molecular framework, giving rise to the enhancement of 2PA cross-section (σ2) value up to 1871 GM at 730 nm, which is the highest value among the reported TADF emitters.[3] The benchmark molecular design for TADF and 2PA materials offers a venue for designing efficient TADF emitters with exceptional 2PA properties.
References
H. Uoyama et al. Nature, 2012, 492, 234−238.
U. Balijapalli et al. Angew. Chem. Int. Ed, 2021, 60, 19364-19373.
G. V. Mageswari et al. Angew. Chem. Int. Ed, 2024, e202420417.
References
H. Uoyama et al. Nature, 2012, 492, 234−238.
U. Balijapalli et al. Angew. Chem. Int. Ed, 2021, 60, 19364-19373.
G. V. Mageswari et al. Angew. Chem. Int. Ed, 2024, e202420417.