Article
Chemistry, Applied
Siqi Zhu, Fang Li, Claire Empel, Sripati Jana, Chao Pei, Rene M. Koenigs
Summary: Here, we report a photocatalytic reaction of acceptor/acceptor diazoalkanes with terminal alkynes, leading to the formation of furan heterocycles. Experimental and computational studies reveal the involvement of a key triplet carbene intermediate, which undergoes addition reaction followed by cyclization. This reaction provides a mild and efficient method for the synthesis of furans using a broad range of substrates.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Physical
Courtney A. DelPo, Saeed-Uz-Zaman Khan, Kyu Hyung Park, Bryan Kudisch, Barry P. Rand, Gregory D. Scholes
Summary: Enhanced delocalization is beneficial for absorbing molecules in organic solar cells, and polaritons offer exceptional delocalization that can improve the efficiency of bilayer organic photovoltaics by aiding in exciton delivery to the donor-acceptor interface. The decay of polaritons in bilayer cavities shows an additional pathway through charge transfer, indicating that the charge transfer from the polariton is fast enough to outcompete decay to the ground state.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2021)
Article
Optics
Ines G. Tavares, Erki Enkvist, Joosep Kaimre, Asko Uri, Fernando B. Dias
Summary: This work investigates the intramolecular energy transfer between two thiophene donors and a perylene bisimide acceptor, demonstrating the transfer of energy from the thiophene donor's excited triplet state to the perylene bisimide acceptor's singlet state. The designed organic luminophore, ARC-1467, shows delayed fluorescence of perylene bisimide upon excitation of the donor unit, indicating the occurrence of energy transfer from the triplet state of the donor unit to the perylene bisimide acceptor.
JOURNAL OF LUMINESCENCE
(2021)
Article
Multidisciplinary Sciences
He Jiang, Jibiao Jin, Zijie Wang, Wuji Wang, Runfeng Chen, Ye Tao, Qin Xue, Chao Zheng, Guohua Xie, Wei Huang
Summary: This research introduces a dynamic approach to construct organic semiconductors with bipolar transporting character by utilizing resonance variation to achieve efficient and balanced charge transport, leading to high external quantum efficiencies in blue and deep-blue phosphorescent organic light emitting diodes.
Article
Chemistry, Organic
Maryam F. Abdollahi, Yuming Zhao
Summary: A class of wedge-shaped organic pi-fluorophores were synthesized and characterized. Among them, a pi-extended PI derivative showed versatile solid-state packing properties and solvatofluorochromism. Another PI derivative functionalized with two electron-donating DTF end groups exhibited redox reactivities and quenched fluorescence. Treatment of the DTF-PI compound with iodine resulted in the formation of fascinating macrocyclic products. Mixing with fullerene in an organic solvent led to substantial fluorescence enhancement due to oxidative C = C bond cleavages.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Paola Zimmermann Crocomo, Takahito Kaihara, Soki Kawaguchi, Patrycja Stachelek, Satoshi Minakata, Piotr de Silva, Przemyslaw Data, Youhei Takeda
Summary: Novel electron donor-acceptor-donor compounds were designed and synthesized with dibenzo[a,j]phenazine as the central acceptor core and two 7-membered diarylamines as the donors. Slight structural modification led to unique photophysical behavior, including dual emission from room-temperature phosphorescence and triplet-triplet annihilation, as revealed by physicochemical analysis and quantum chemical calculations. Electrochemical analysis suggested sigma-dimer formation and electrochemical polymerization on the electrode.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Physical
Chengxi Li, Xue Jin, Jianlei Han, Tonghan Zhao, Pengfei Duan
Summary: This article discusses the circularly polarized luminescence (CPL) activity of chiroptical materials, emphasizing the importance of increasing the dissymmetry factor glum value. Recent studies have shown that amplification of glum value can be achieved in hybrid donor-acceptor systems, providing new insights for the development of highly efficient CPL materials.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Haonan Zhao, Jongchan Kim, Kan Ding, Mina Jung, Yongxi Li, Harald Ade, Jun Yeob Lee, Stephen R. Forrest
Summary: By incorporating a sterically bulky, electron-transporting host material into a conventional single host-guest emissive layer, the phase separation of the host matrix can be suppressed, leading to improved efficiency and operational lifetime of deep-blue phosphorescent organic light-emitting diodes (PHOLEDs). This bulky host allows for homogeneous mixing of the emissive layer molecules while preventing single host aggregation and nonradiative recombination. The controlled amorphous phase morphology of the mixed-host device reduces nonradiative exciton decay and enhances external quantum efficiency by 120 +/- 6% compared to a similar single-host device. Additionally, the mixed host facilitates the conduction of both charge carriers, reducing the probability of exciton annihilation and doubling the operational lifetime of deep-blue PHOLEDs.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Physical
Weijun Wu, Andrew E. E. Sifain, Courtney A. A. Delpo, Gregory D. D. Scholes
Summary: This study theoretically investigates the quantum dynamics of a donor-acceptor cavity system and finds that polaritons have the potential to enhance free charge carrier generation on an ultrafast timescale, but are suppressed by internal conversion and cavity loss on a longer timescale.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
Pandiselvi Durairaj, Kiruthika Samuthirapandi, Sunandan Sarkar
Summary: The structure-property relationships of different conformers of an organic D-A-D triad have been investigated in order to understand the structural motif affecting photoluminescence activity. In a recent experiment, it was found that the PTZ-DBPHZ-PTZ (D-A-D) triad exhibited multicolor luminescence properties and thermally activated delayed fluorescence (TADF) emission. Computational studies were conducted to analyze the photophysical properties of the conformers and provide a detailed description of the luminescence activity. The results showed that the twisting of the axial phenothiazine (PTZ) unit to an equatorial position changed the nature of the S1 state and caused a large red shift in emission energy.
JOURNAL OF PHYSICAL CHEMISTRY A
(2023)
Article
Chemistry, Multidisciplinary
Xinrui Liu, Liuqing Yang, Xuefei Li, Lei Zhao, Shumeng Wang, Zheng-Hong Lu, Junqiao Ding, Lixiang Wang
Summary: A novel electroactive room-temperature phosphorescence (RTP) polymer with significant RTP characteristics in solid states has been developed, showing a record-high external quantum efficiency of 9.7% in electrophosphorescence. This performance surpasses the theoretical limit for typical fluors, suggesting potential for efficient pure organic light-emitting diodes in the future.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Alexander Aster, Christopher Rumble, Anna-Bea Bornhof, Hsin-Hua Huang, Naomi Sakai, Tomas Solomek, Stefan Matile, Eric Vauthey
Summary: The study focuses on the charge-transfer dynamics of electron donor-acceptor dyads based on NDI chromophores, demonstrating long-lived charge separation in the triplet state can be achieved by controlling the mutual orientation of the donor-acceptor sub-units.
Article
Chemistry, Physical
Jumi Park, Jooyoung Sung, Dongho Kim
Summary: In this study, the charge transfer (CT) processes in donor-pyreneacceptor (DPA) molecules were deciphered using various time-resolved spectroscopic measurements. The ultrafast CT rate of approximately 200 fs in DPA molecules was observed, indicating isoenergetic potential surfaces for LE and CT states. Strong electronic coupling between the LE and CT states was found upon the introduction of the acceptor to the pyrene moiety in DPA systems.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Matthew R. Lasky, Tolani K. Salvador, Sukrit Mukhopadhyay, Matthew S. Remy, Thomas P. Vaid, Melanie S. Sanford
Summary: This report describes the development of a photochemical method for C(sp(2))-H pyridination that leverages the photoexcitation of electron donor-acceptor (EDA) complexes. The reaction results in aryl radical cation intermediates that can be trapped with pyridine nucleophiles under aerobic conditions. This approach eliminates the need for an exogenous photocatalyst and is cost-effective.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Materials Science, Multidisciplinary
Dong Jun Kim, Sunhee Lee, Yong Hui Lee, Hyungkeun Jang, Kwang-Hyun Ahn, Won-Sik Han
Summary: Effective host materials play a crucial role in enhancing the performance of phosphorescent organic light-emitting diodes. In this study, a series of triazine-dibenzofuran-based n-type host materials were synthesized, with the position of dibenzofuran substitution found to significantly impact the chemical structure and properties. Among the developed materials, the green PhOLEDs utilizing DBT4/BPCz as a mixed host exhibited the best EL performance, showcasing high current efficiency, external quantum efficiency, power efficiency, and a device lifetime of 180 hours at 10,000 nits.
JOURNAL OF MATERIALS CHEMISTRY C
(2021)
Article
Engineering, Environmental
Shuo Chen, Chunying Zhang, Hui Xu
Summary: The development of near-ultraviolet (NUV) emitters with wide band gap and high photoluminescence quantum efficiency (PLQY) for organic light-emitting diode (OLED) applications is a significant challenge. By utilizing crescent phenanthrene (Phen) fused with acceptor imidazole (Im) as NUV chromophore, and introducing steric hindrance for aggregation suppression and triphenylphosphine to enhance electronic states, the designed PhImPOCz and PhImPOtBuCz emitters achieved low turn-on voltages and high external quantum efficiency. This work highlights the importance of electronic state engineering in high-energy OLED applications.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Chemistry, Multidisciplinary
Jiteng Ni, Chunlei Zhong, Liyuan Li, Mengxue Su, Xinran Wang, Jianan Sun, Shuo Chen, Chunbo Duan, Chunmiao Han, Hui Xu
Summary: The translation briefly introduces the optoelectronic applications of clusters and the potential of cluster light-emitting diodes (CLEDs), pointing out the lack of deep-blue CLEDs reported so far. It then discusses the two chosen clusters and their contributions to deep-blue CLEDs. Finally, it mentions the high-resolution display capabilities of CLEDs based on device engineering.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Zhuliang Lin, Yi Man, Ziyue Lv, Baoping Zhang, Hui Xu, Daquan Yu, Xingchen Yang, Yan He, Xiaowu Shi, Leiying Ying, Dan Zhang
Summary: Chelate phosphine oxide ligand (9,9-dimethyl-9H-xanthene-4,5-diyl) bis (diphenylphosphineoxide) (XPO) is used as a neutral ligand to synthesize complex Nd (TTA)(3) (XPO) (TTA = 2-thenoyltrifluoroacetone). The appropriate energy gap between XPO and TTA ligands supports energy transfer from T-1 state of XPO to TTA, leading to improved energy transfer in the Nd complex. Optical gains at 1.06 and 1.31 μm are achieved in Nd (TTA)(3) (XPO)-doped polymer waveguides using low-power LEDs as pump sources instead of semiconductor lasers.
ADVANCED MATERIALS
(2023)
Article
Engineering, Environmental
Chao Qu, Huiqin Wang, Yi Man, Zhe Li, Peng Ma, Peng Chang, Xin Li, Chunmiao Han, Yudong Pang, Hui Xu
Summary: A feasible strategy of D-A-A structure is proposed to improve the PL and EL performance of red TADF emitters. Four newly designed and synthesized TADF emitters with D-A-A and D-A-D structures are demonstrated. The asymmetric compounds show abundant intra- and inter-molecular C-H···O hydrogen bonds, promoting charge transfer. Additionally, the steric hindrance of DPPO group effectively suppresses concentration quenching, resulting in better PL quantum yields and lower nonradiation rates.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Chemistry, Physical
Yuyang Huang, Yi Man, Guohua Xie, Ce Wang, Baoping Zhang, Hui Xu, Hongyan Fu, Jiyun Zhu, Ziyue Lv, Leiying Ying, Feng Xia, Dan Zhang
Summary: By utilizing the molecular energy transfer mechanism, relative gains at 1067 and 637 nm wavelengths are achieved in polymer waveguides doped with thermally activated delayed fluorescence molecule AQ(PhDPA)(2) and Nd complex with chelating phosphine oxide as ligands, using low-power UV LEDs as pump sources. The gains at 1067 nm are 2.2 and 1.8 dB cm(-1) under excitation of 300 mW 405 nm LED, and the gains at 637 nm are 3.9 and 4.9 dB cm(-1) with pumping of 530 mW 450 nm LED, respectively. With the addition of a 100 nm-thick aluminum reflector, the optical gain at 1067 and 637 nm can be enhanced to 3.5 and 6.1 dB cm(-1), corresponding to AQ(PhDPA)(2)-Nd(DBTTA)(3)(DBFDPO) and AQ(PhDPA)(2)-Nd(DBTTA)(3)(FDPO)-doped PMMA polymers, respectively.
Article
Chemistry, Multidisciplinary
Ying Li, Xianfa Zhang, Yi Man, Shiwei Xu, Jing Zhang, Guangming Zhang, Shuo Chen, Chunbo Duan, Chunmiao Han, Hui Xu
Summary: The key factor limiting optoelectronic performances of organic-inorganic hybrid systems, which is defect, has been overcome through interfacial passivation by electron transporting layers (ETL). By using TmPyPB as ETL, the photoluminescence (PL) and electroluminescence (EL) quantum efficiencies of monophosphine Cu4I4 cube [TPP](4)Cu4I4 are significantly improved, resulting in a huge increase in luminance from nearly unlighted state to highly bright state. The passivation effect of TmPyPB on surface defects of cluster layer is manifested in the prevention of interfacial charge trapping and suppression of exciton nonradiation.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Nan Zhang, Ying Li, Sanyang Han, Ying Wei, Huan Hu, Ran Huo, Chunbo Duan, Jing Zhang, Chunmiao Han, Guohua Xie, Hui Xu
Summary: Clusters combine the advantages of organic molecules and inorganic nanomaterials, providing promising alternatives for optoelectronic applications. The optimization of excited states of cluster emitters, particularly reducing population of the cluster-centered triplet quenching state, is important for cluster light-emitting diodes. In this study, redox-active ligands were found to enhance reverse intersystem crossing (RISC) of Cu4I4 cluster for triplet-to-singlet conversion, while thermally activated delayed fluorescence (TADF) host served as an external RISC channel.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Xiaoqing Song, Guang Lu, Yi Man, Jing Zhang, Shuo Chen, Chunmiao Han, Hui Xu
Summary: In this study, three carbazole-triphenylphosphine hybrids were designed and synthesized to achieve high efficiency and long lifetime of organic room temperature phosphorescence (RTP). The para-substituted pCzTPP showed high RTP efficiency (>10%) and extended lifetime (>600 ms), surpassing the ortho- and meta- isomers. Theoretical simulation and photophysical investigation revealed that the strong intermolecular p-p and p-p interactions in pCzTPP facilitated the transition probability and triplet stability of (3)pp state, demonstrating the synergy of p-p and p-p in RTP process.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Jibiao Jin, Chunbo Duan, He Jiang, Peng Tao, Hui Xu, Wai-Yeung Wong
Summary: Developing deep-blue TADF emitters with high efficiency and color purity is challenging. A design strategy integrating asymmetric O-B-N MR unit into traditional N-B-N MR molecules was proposed. Three deep-blue MR-TADF emitters with different MR units were synthesized, and the proof-of-concept emitter ODBN showed respectable deep-blue emission. The OLED using ODBN as emitter achieved a high external quantum efficiency of 24.15% with deep-blue emission.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Green & Sustainable Science & Technology
Wei Ge, Hai-tao Yu, Chun-miao Han, Ying Xie, Ting-feng Yi
Summary: A series of anode materials, Li2ZnTi3O8 (LZTO) and Li2-xZnTi3-xNbxO8 (x = 0.2, 0.4, and 0.5) (LZTNO), were designed. The introduction of Nb5+ dopants improved the electrochemical performances of the composites by reducing lithium content and altering their intrinsic characteristics. The best electrochemical performance was observed in the LZTNO-2 sample, which showed a charge/discharge capacity of 182.7/181.2 mAh g(-1) at 1 A g(-1) after 500 cycles, higher than LZTO (100.41/100.41 mAh g(-1)). The study suggests that introducing high valence dopants effectively modifies the stoichiometry and lithium content of anode materials, enhancing their specific capacity and electrochemical performances.
ADVANCED SUSTAINABLE SYSTEMS
(2023)
Article
Chemistry, Multidisciplinary
Ying Xin, Yonglin Zhu, Ruixin Chi, Chunbo Duan, Pengfei Yan, Chunmiao Han, Hui Xu
Summary: This study demonstrates an effective strategy to achieve balanced intra- and interchain charge transfer in non-conjugated copolymers by optimizing the inductive and steric effects of the acceptors, resulting in greatly enhanced performance of thermally activated delayed fluorescence polymers.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Ying Li, Siwei Xu, Xianfa Zhang, Yi Man, Jing Zhang, Guangming Zhang, Shuo Chen, Chunbo Duan, Chunmiao Han, Hui Xu
Summary: By using a bulky passivation strategy and an active matrix, efficient light-emitting diodes with high quantum yields and luminance can be achieved.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Physical
Xin Gao, Yumeng Chen, Xueting Jiao, Xiang Li, Yuwei Chen, Zhenzhong Lu, Cong Zhang, Xiao-Chun Hang, Hui Xu, Wei Huang
Summary: Two novel Pt(II) complexes, Pt(pzpyOppz-A) and Pt(pzpyOppz-B), were developed for excimer-based emissions. These complexes can readily form dimers in a solid matrix, resulting in excimer-based emission with high photoluminescence efficiency. By utilizing dual emission bands, efficient phosphorescent organic light-emitting diodes (PhOLEDs) with a broad spectral emission were fabricated. The Pt(pzpyOppz-A) device achieves a broad yellowish-white emission with high efficiencies, while the Pt(pzpyOppz-B) device exhibits exclusive excimer-based emission.
CHEMISTRY OF MATERIALS
(2023)
