Article
Engineering, Environmental
Hao Sun, Shan-Shan Sun, Fang-Fang Han, Yun Zhao, Ming-De Li, Bao-Xi Miao, Jing Nie, Ran Zhang, Zhong-Hai Ni
Summary: The synthesized TPENOCN can achieve dynamic fluorescence switching induced by water, with potential applications in data security and anti-counterfeiting.
CHEMICAL ENGINEERING JOURNAL
(2021)
Article
Chemistry, Physical
Xiaobin Chen, Dehui Tan, Jiaqi Dong, Tinghao Ma, Yi Duan, Deng-Tao Yang
Summary: In this research, a facile synthesis method was developed to modify the structure of [4]triangulene by replacing its carbon edges with oxygen-boron-oxygen units. The resulting compounds, termed OBO-modified [4]triangulenes, exhibited excellent thermal stability and rare fluorescence and phosphorescence emissions from multiple higher excited states.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Review
Biochemistry & Molecular Biology
Daniele Malpicci, Elena Lucenti, Clelia Giannini, Alessandra Forni, Chiara Botta, Elena Cariati
Summary: In recent years, anti-Kasha behavior has sparked intense debate, with research focusing on both mechanistic and applicative aspects. This review collects examples of anomalous emitters reported in the last 10 years, specifically focusing on strictly anti-Kasha organic molecules displaying radiative deactivation from S-n and/or T-n.
Article
Chemistry, Organic
Prabhu Ganesan, Paramaguru Ganesan, Zilong Zhang, Jianbin Xu, Renganathan Rajalingam, Peng Gao
Summary: Imidazole-based donor-acceptor materials exhibit polarity-controlled trade-off between short-wavelength (SW) emission and long-wavelength (LW) emission. By synthesizing and verifying imidazole-based donor-acceptor fluorophores with different electron-donating groups, it was found that certain compounds showed dual emission in solvents of varying polarity, while others only exhibited SW emission. DFT calculations and experimental results revealed the different origins of SW and LW emissions. This work provides a new approach for achieving concurrent SW and LW emission characteristics and offers insights for the design of panchromatic emitters for lighting and display applications.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Multidisciplinary Sciences
Jiuyang Li, Xun Li, Guangming Wang, Xuepu Wang, Minjian Wu, Jiahui Liu, Kaka Zhang
Summary: The emission maximum of phosphorescence is usually longer than that of fluorescence. In this study, researchers report a serendipitous finding of up-converted room-temperature phosphorescence (RTP) with emission maximum smaller than that of fluorescence. This is achieved by doping benzophenone-containing difluoroboron beta-diketonate (BPBF2) into phenyl benzoate matrices. The up-converted RTP originates from BPBF2's higher-lying triplet states with (3n-pi*) characters and large phosphorescence rates, violating Kasha's rule.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Daniela Cappello, Francis L. Buguis, Joe B. Gilroy
Summary: Molecular materials with pi-conjugated donor-acceptor and acceptor-donor-acceptor structures have versatile applications in organic photovoltaic materials, organic light-emitting diodes, and biological imaging agents. Boron-containing compounds with unique optoelectronic and redox properties are synthesized using Stille cross-coupling chemistry. The compounds exhibit reversible redox waves, solid-state emission, and aggregation-induced emission. The optical band gaps determined from experiments and density functional theory calculations support the rationalization of the observed optoelectronic properties. This study provides a foundation for incorporating these boron-containing compounds into applications that require fine-tuning of band gaps.
Article
Chemistry, Physical
Shalu Gupta, Marilyn Daisy Milton
Summary: Seven novel donor-acceptor-donor type push-pull quadrupolar quinoxaline scaffolds with blue or green emission in solution were successfully synthesised via Heck coupling reaction, showing tunable photophysical properties. The compounds exhibited large Stokes shifts and bathochromic shifts in emission wavelength, along with a twisted structural conformation and donor-acceptor interactions revealed by XRD studies. Reversible fluorescence switching and color modulation upon treatment with TFA and TEA were observed, with potential applications in detecting volatile acids.
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Xingdong Wang, Jun Hu, Jianhong Lv, Qingqing Yang, Hongkun Tian, Shiyang Shao, Lixiang Wang, Xiabin Jing, Fosong Wang
Summary: Pi-stacked dendrimers with cofacial alignment of donors and acceptors were developed by introducing unique dendritic teracridan donors and triazine acceptors, leading to through-space charge transfer emission with thermally activated delayed fluorescence. By adjusting the charge transfer strength, the emission color of the dendrimers can be tuned, achieving high efficiency two-color white OLEDs.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Review
Chemistry, Multidisciplinary
Daniel Escudero, Koen Veys
Summary: The study reveals various exceptions to Kasha's rule and different types of anomalous fluorescence phenomena. Through quantum chemical investigations, three types of anti-Kasha scenarios are highlighted, which may provide theoretical support for the design and application of new fluorescence properties.
ACCOUNTS OF CHEMICAL RESEARCH
(2022)
Article
Chemistry, Multidisciplinary
Midori Kawashiro, Tatsuya Mori, Masato Ito, Naoki Ando, Shigehiro Yamaguchi
Summary: A new class of donor-pi-acceptor fluorophores with ortho-P(=X)R-2-substituted phenyl groups (X=O or S) as a photodissociation module is reported. The P=X moiety coordinates to the boron atom and undergoes dissociation in the excited state, resulting in dual emission from tetra- and tricoordinate boron species. The intensity ratios of the dual emission bands are sensitive to environmental parameters and single-molecule white emission can be achieved by precise tuning of the P(=X)R-2 group and the electron-donating amino moiety in solution.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Review
Chemistry, Multidisciplinary
Xi Chen, Xue Zhang, Xiao Xiao, Zhijia Wang, Jianzhang Zhao
Summary: Charge transfer is crucial in molecular electron donor-acceptor systems for artificial photosynthesis, photocatalysis, photovoltaics, and fundamental photochemistry. We summarized recent developments in the study of charge transfer and discussed its application in thermally activated delayed fluorescence (TADF) emitters.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Inorganic & Nuclear
Yangbin Xie, Luying Liu, Zetao Huang, Huixian Miao, Wenjiang Zhaxi, Fengnan Duan, Wei Huang, Dayu Wu
Summary: In this study, the observation of anti-Kasha's rule emission in a multicomponent three-dimensional nanotubular metal-organic framework (MOF-NT) was reported. The MOF-NT displayed strong excitation-dependent fluorescence from the ultraviolet to the visible spectral region and showed a discriminative photoluminescence response to isomeric nitroaromatic compounds. This work demonstrated the intrinsic anti-Kasha's rule emission in crystalline-state MOF materials and provided new perspectives for the development of advanced solid-state emissive materials.
INORGANIC CHEMISTRY
(2023)
Article
Multidisciplinary Sciences
Jianwei Shen, Ajay Jha, Meng Lv, Guanyu Jiang, Qixu Zhao, Zihui Liu, Jinquan Chen, Yan Yang, Haitao Sun, Hong-Guang Duan, Zhenrong Sun
Summary: Merocyanine dyes are of great interest due to their nonlinear optical properties and solvatochromism. In this study, the excited state dynamics of a merocyanine dye known as HB194 were investigated, revealing solvent-dependent charge transfer dynamics. The excited state decays in different solvents showed multi-exponential components, with polar solvents inducing conformationally relaxed intramolecular charge transfer states and nonpolar solvents exhibiting solvent-stabilized ICT states. An anomalously red-shifted emission was observed in ethylene glycol, which was attributed to the presence of molecular dimers. This work emphasizes the importance of gaining molecular-level insight into system-solvent interactions for designing next-generation merocyanine-based solvatochromic dyes.
SCIENTIFIC REPORTS
(2022)
Article
Chemistry, Multidisciplinary
Chao Wu, Weiqiang Liu, Kai Li, Gang Cheng, Jinfan Xiong, Teng Teng, Chi-Ming Che, Chuluo Yang
Summary: Intramolecular through-space charge-transfer (TSCT) excited states are utilized for developing thermally activated delayed fluorescence (TADF) emitters, with a series of precisely controlled TSCT emitters designed through alignment optimization of donor and acceptor segments. By increasing intramolecular pi-pi interactions, radiative decay rate of the lowest singlet excited state (S-1) is progressively enhanced with suppression of nonradiative decay, leading to significantly improved photoluminescence quantum yields of up to 0.99 in doped thin films. A high-efficiency electroluminescence device achieves a maximum external quantum efficiency (EQE) of 23.96% and maintains >20% at a brightness of 1000 cd m(-2), highlighting the importance of conformation control for high-efficiency intramolecular exciplex emitters.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Multidisciplinary Sciences
Tao Wang, Zhubin Hu, Xiancheng Nie, Linkun Huang, Miao Hui, Xiang Sun, Guoqing Zhang
Summary: Aggregation-induced emission (AIE) is a successful strategy for achieving highly efficient room temperature phosphorescence (RTP) by limiting molecular motions. In this study, the authors demonstrate a novel design strategy by combining AIE and donor-acceptor motifs to achieve unusual thermochromic dual phosphorescence.
NATURE COMMUNICATIONS
(2021)