Article
Polymer Science
Shuaiyuan Han, Yichao Zheng, Jit Sarkar, Hiroshi Niino, Shunsuke Chatani, Atsushi Goto
Summary: This paper reports the first use of organic chloride salts as catalysts for reversible complexation mediated living radical polymerization. The chloride salt catalysts have wide monomer scope, good livingness, accessibility to block copolymers, and good solubility in organic media. Therefore, the use of chloride salt catalysts is industrially attractive and may lower the cost of polymerization.
MACROMOLECULAR RAPID COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Zhen Lu, Rui Zhao, Hongjie Yang, Xiaoling Fu, Yulai Zhao, Longqiang Xiao, Linxi Hou
Summary: Two imine-based covalent organic framework photocatalysts, TPB-DMTA-COF and TAT-DMTA-COF, were developed for photo-induced energy transfer reversible complexation-mediated radical polymerization (PET-RCMP). The results showed that both photocatalysts produced ideal polymers with accurate molecular weight and moderate dispersity under visible light irradiation. The compatibility of RCMP processes in both bulk and aqueous system was also demonstrated. Moreover, density functional theory (DFT) calculations verified the higher activity of the heteroatom-doped TAT-DMTA-COF in weakening C-I bond energy barrier.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Polymer Science
Kazuya Ohtani, Kanta Shimizu, Tatsuhiro Takahashi, Masumi Takamura
Summary: A novel chain-end modification of polymer iodides via reversible complexation-mediated polymerization with different functionalized radical generation agents was developed. The reaction mechanism was probed using MALDI-TOF MS, and the key factors for efficiency were the combination rate constant and the amount of radicals generated per unit of time.
Article
Polymer Science
Weijia Mao, Xiu Ting Tay, Jit Sarkar, Chen-Gang Wang, Atsushi Goto
Summary: An air-tolerant reversible complexation mediated polymerization (RCMP) technique has been developed, which does not require deoxygenation. The technique uses aldehyde, N-hydroxyphthalimide (NHPI), and a base as catalysts. The oxygen in the system is consumed through NHPI-catalyzed conversion to carboxylic acid, which is then converted to carboxylate anion by the base. This technique is applicable to various monomers and produces polymers with low dispersity.
MACROMOLECULAR RAPID COMMUNICATIONS
(2022)
Review
Polymer Science
Graeme Moad
Summary: This paper discusses the development of the term 'reversible-deactivation radical polymerization (RDRP)' and highlights the significance of the paper that introduced this term.
POLYMER INTERNATIONAL
(2023)
Article
Polymer Science
Xia Lin, Qianxi Gu, Jiajia Li, Jian Zhu
Summary: In this study, a facile and robust method for living cationic polymerization using zinc wire as a catalyst precursor was developed. Well-defined poly(vinyl ether)s with various molecular weights and narrow molecular weight distributions were obtained at room temperature. The in situ generation of trace zinc ions was found to be the key to the mild conditions of the polymerization. The utilization of zinc wire offered advantages of reusability, easy separation, and low metal residue. Moreover, the method was successfully applied in continuous flow polymerization, showing potential for scalable and efficient industrial production under mild conditions.
Article
Polymer Science
Jin-Ying Wang, Yuan-Yuan Ni, Jian-Nan Cheng, Li-Fen Zhang, Zhen-Ping Cheng
Summary: The article introduces a strategy combining RCMP and SET-DTLRP to adjust the dispersity of polymers, successfully preparing a block copolymer with adjustable dispersity.
CHINESE JOURNAL OF POLYMER SCIENCE
(2021)
Article
Polymer Science
Hien The Ho, Veronique Montembault, Sagrario Pascual, Laurent Fontaine, Didier Gigmes, Trang N. T. Phan
Summary: A novel alkyl iodide compound was synthesized and used as an initiator for polymerization reactions. The new initiator showed high efficiency in producing functional polymers through thermal and photochemical activation.
Article
Chemistry, Multidisciplinary
Q. Li, R. Zhao, Z. Lu, L. Xiao, L. Hou
Summary: This article presents the research on a halogen-free covalent organic framework (TAPPy-TFPPy-COF) based on imine bonds for the reversible polymerization under white light irradiation. By energy transfer, the polymerization reaction is initiated, resulting in polymers with controllable molecular weight and relatively uniform distribution. The obtained polymer has high chain end fidelity.
MATERIALS TODAY CHEMISTRY
(2022)
Article
Polymer Science
Fehaid M. Alsubaie, Othman Y. Alothman, Hassan Fouad, Abdel-Hamid I. Mourad
Summary: This study reported the aqueous Cu(0)-mediated reversible deactivation radical polymerization (RDRP) of triblock copolymers with two block sequences at 0.0 degrees C. Sequence-controlled triblock copolymers were successfully synthesized via ultrafast one-pot synthesis and without any purification steps throughout the monomer additions. The resulting copolymers exhibited narrow dispersities, controlled chain length, and quantitative conversion.
Article
Polymer Science
Soumaya Kouki, Najeh Jaoued-Grayaa, Amira Anene, Emmanuel Beyou, Yves Chevalier, Souhaira Hbaieb
Summary: This study investigates the origin of the improved performance of Molecular Imprinted Polymers (MIPs) prepared by Nitroxide-Mediated Radical Deactivation Reversible Polymerization (NMRP) and by conventional Free Radical Polymerization (FRP). The study reveals that the enhanced adsorption of NMRP MIPs is due to a higher density of molecular imprints rather than a higher affinity. Additionally, hydrogen bonding between the MIP carboxylic acids and the target molecule is found to be the main contribution to adsorption.
Article
Polymer Science
Fehaid M. Alsubaie, Othman Y. Alothman, Basheer A. Alshammari, Hassan Fouad
Summary: In this study, copper-mediated reversible deactivation radical polymerization of homo-polyacrylamides was conducted in aqueous solutions at 0.0 degrees C, resulting in well-defined water-soluble homopolymers with narrow dispersity. The effect of decreasing the reaction temperature on the polymerization rate was also investigated, showing that temperatures below 0.0 degrees C did not affect the controlled polymerization and process rate.
Article
Polymer Science
Satu Hakkinen, Billy Dyer, Andrew Kerr, Sebastien Perrier
Summary: This versatile synthetic methodology utilizes Z group-tethered grafts to facilitate intermolecular graft exchange reactions between distinct starting materials, resulting in graft copolymers with mixed graft distributions.
Review
Chemistry, Multidisciplinary
Ruoyu Li, Weina Kong, Zesheng An
Summary: This Minireview discusses the key roles enzymes play in reversible deactivation radical polymerization (Enz-RDRP) and highlights their applications in surface brush fabrication, sensing, polymerization-induced self-assembly, and high-throughput synthesis. The authors also reflect on the challenges and future directions of this emerging area.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Review
Polymer Science
Zhi-Hao Chen, Xiao-Yan Wang, Yong Tang
Summary: This review summarizes the research on RCMP in the last ten years, mainly focusing on the development of catalytic systems, photo-induced RCMP, and the special applications derived from their inherent characteristics.
Article
Chemistry, Physical
Samrat Ghosh, Yusuke Tsutsui, Takahiro Kawaguchi, Wakana Matsuda, Shusaku Nagano, Katsuaki Suzuki, Hironori Kaji, Shu Seki
Summary: This study developed crystalline pi-conjugated covalent organic frameworks (COFs) and demonstrated their potential in terms of conductivity and photoresponsivity, providing new active materials for multifunctional organic electronics.
CHEMISTRY OF MATERIALS
(2022)
Article
Polymer Science
Yuji Kinose, Keita Sakakibara, Yoshinobu Tsujii
Summary: Cellulosic bottlebrushes with polystyrene and poly(ethylene glycol) side chains were synthesized and characterized to reveal the second structure. The bottlebrushes were found to have a core-shell-corona structure, where the PEG and PS side chains formed a homogeneous shell layer surrounding the cellulosic core, and the outer segments of PS chains formed an outer corona layer. The PEG side chains effectively suppressed the internal rotation of the cellulosic main chain.
Article
Nanoscience & Nanotechnology
Sharvan Kumar, Yun Hee Koo, Tomohiro Higashino, Wakana Matsuda, Samrat Ghosh, Yusuke Tsutsui, Masayuki Suda, Hiroshi Imahori, Katsuaki Suzuki, Hironori Kaji, Shu Seki
Summary: The preparation and characterization of a new class of electron deficient organic compounds, truxenone triimide (TTI), is reported. The electrochemical analysis confirms that multi-imidization helps in lowering the LUMO energy level, resulting in improved optoelectronic and/or semiconducting properties. The charge carrier transport properties and dynamics of the compounds are studied using flash-photolysis time-resolved microwave conductivity measurements. Compound 2D exhibits a high electron mobility of 0.27 cm(2) V-1 s(-1) under ambient conditions.
ADVANCED ELECTRONIC MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Dongdong Zhang, Yoshimasa Wada, Qi Wang, Hengyi Dai, Tianjiao Fan, Guoyun Meng, Jinbei Wei, Yuewei Zhang, Katsuaki Suzuki, Guomeng Li, Lian Duan, Hironori Kaji
Summary: This study proposes a novel D-void-A structure for TADF emitters, which achieves high efficiency and blue-shifted emission by connecting D and A moieties at the void position between donor and acceptor segments. Compared to the contrast D-A isomers, the TADF emitter in this study exhibits more efficient and blue-shifted emission. Additionally, the involvement of the lower HOMO-2 of the acceptor segment in conjugation provides a wider energy gap.
Article
Chemistry, Multidisciplinary
Yu Kusakabe, Yoshimasa Wada, Tomoya Misono, Katsuaki Suzuki, Katsuyuki Shizu, Hironori Kaji
Summary: Members of the imidazole family are widely used in the field of electron transporting, host, fluorescent, and phosphorescent materials. However, the emission color of imidazole-based organic light-emitting diodes (OLEDs) has been limited to blue to green. In this study, four acridan-imidazole systems are designed to achieve deep or pure-blue emission, and one of them exhibits a high external quantum efficiency (EQEMAX) in its application to OLEDs.
Article
Chemistry, Multidisciplinary
Katsuyuki Shizu, Hironori Kaji
Summary: This study provides a comprehensive understanding of the emission mechanism of a representative multiple resonance-type thermally activated delayed fluorescence (MR-TADF) molecule. Through calculations, the rate constants and photoluminescence quantum yield related to the emission mechanism were quantified.
COMMUNICATIONS CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Natsuo Nagamura, Hisahiro Sasabe, Hiroki Sato, Nozomi Ito, Shoki Abe, Yoshihito Sukegawa, Daisuke Yokoyama, Hironori Kaji, Junji Kido
Summary: Using a tailored high triplet energy hole transport layer is an effective way to improve the efficiency and lifetime of organic light-emitting devices. In this study, two HTL materials were developed and showed excellent performance in terms of external quantum efficiency and operational lifetime in green phosphorescent OLEDs.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Physics, Applied
Natsuko Kanno, Yongxia Ren, Yu Kusakabe, Katsuaki Suzuki, Katsuyuki Shizu, Hiroyuki Tanaka, Yoshimasa Wada, Hiromichi Nakagawa, Jan Geldsetzer, Hironori Kaji
Summary: Accelerating reverse intersystem crossing (RISC) without sacrificing fast radiative decay is effective in suppressing efficiency roll-off (eRO) in thermally activated delayed fluorescence (TADF)-based organic light-emitting diodes. We here report a TADF emitter, CC-TXO-I, combining a bicarbazole donor (CC) and a sulfur-containing acceptor (TXO). We realized very large rate constants of RISC (k (RISC)s) of similar to 10(7) s(-1). Both k (RISC)s and rate constants of radiative decay of CC-TXO-I increased with increasing doping concentration, resulting in improved eROs.
APPLIED PHYSICS EXPRESS
(2023)
Article
Chemistry, Physical
Katsuyuki Shizu, Yongxia Ren, Hironori Kaji
Summary: Thermally activated delayed fluorescence (TADF) molecules show potential for durable organic light-emitting diodes. Fast reverse intersystem crossing (RISC) can improve their device lifetime. This study focuses on the heavy-atom effect on TADF and proposes a molecular design to enhance RISC. Results indicate that heavier atoms can significantly increase RISC rate constants, but a too heavy-atom effect may hinder both RISC and efficient TADF.
JOURNAL OF PHYSICAL CHEMISTRY A
(2023)
Article
Chemistry, Organic
Dongyang Chen, Yoshimasa Wada, Yu Kusakabe, Liansheng Sun, Eiichi Kayahara, Katsuaki Suzuki, Hiroyuki Tanaka, Shigeru Yamago, Hironori Kaji, Eli Zysman-Colman
Summary: In this study, we investigated the possibility of utilizing cycloparaphenylenes (CPP) in a donor-acceptor TADF emitter design. The compound 4PXZPh-[10]CPP, which contains four electron-donating groups connected to a [10]CPP, exhibited sky-blue emission with a wavelength of 475 nm and a photoluminescence efficiency of 29% in a 15 wt% doped CzSi film. Solution-processed OLEDs incorporating 4PXZPh-[10]CPP displayed sky-blue emission with a wavelength of 465 nm and a maximum external quantum efficiency of 1.0%.
Article
Chemistry, Physical
Hideka Ando, Katsuaki Suzuki, Hironori Kaji, Takashi Kambe, Yuta Nishina, Chiyu Nakano, Kazuma Gotoh
Summary: Dynamic nuclear polarizing (DNP) technique in nuclear magnetic resonance (NMR) is a powerful tool for microanalysis, but its application to carbon materials like graphene oxide (GO) and amorphous carbon has been limited by their electroconductivity and microwave absorption. In this study, DNP-NMR was successfully applied to analyze surface functional groups on GO and sucrose-derived carbon, revealing enhanced peaks of 13C and the presence of previously undetectable functional groups. The dominant enhancement mechanism was found to be the cross effect, except for the CH3 groups on GO, which were mainly enhanced through Overhauser effect or solid effect.
Article
Chemistry, Physical
Hector Miranda-Salinas, Angela Rodriguez-Serrano, Jeremy M. Kaminski, Fabian Dinkelbach, Nakagawa Hiromichi, Yu Kusakabe, Hironori Kaji, Christel M. Marian, Andrew P. Monkman
Summary: We conducted an experimental and theoretical study on the through-space charge transfer in the TADF molecule TpAT-tFFO. Our measurements showed a singular Gaussian line shape fluorescence with two decay components from two distinct molecular CT conformers. The intersystem crossing rate was found to be one order of magnitude faster than radiative decay, leading to quenched prompt emission and observable delayed fluorescence. Time-resolved emission spectra showed a redshift in emission, attributed to the transition from delayed fluorescence to phosphorescence.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Physical
Hiroyuki Tanaka, Yoshiyuki Mizuhata, Norihiro Tokitoh, Riichi Miyamoto, Kazuyoshi Kanamori, Hironori Kaji
Summary: A stimuli-responsive luminophore with a supramolecular organic framework structure has been designed and synthesized. It exhibits reversible and cyclical solid-state phase transitions triggered by external stimuli, such as mechanical grinding, thermal annealing, and solvent treatment, accompanied by color changes in emission.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Materials Science, Multidisciplinary
Yugo Tsuji, Natsuko Kanno, Chigusa Goto, Shohei Katao, Yasuo Okajima, Pablo Reine, Paulius Imbrasas, Sebastian Reineke, Katsuyuki Shizu, Takuya Nakashima, Hironori Kaji, Tsuyoshi Kawai, Marine Louis
Summary: This work presents the synthesis and characterization of a carbazole-naphthalimide donor-acceptor pair for circularly polarized thermally activated delayed fluorescence. The monomeric form shows only fluorescence, while the dimeric form exhibits TADF emission. The dimerization greatly reduces the singlet-triplet energy gap, enabling TADF emission with high photoluminescence quantum yield. In addition, the chiral target shows high performance CPL at room and low temperature, and it undergoes a transition from yellow phase to orange/red phase under mechanical stress.
JOURNAL OF MATERIALS CHEMISTRY C
(2023)
Article
Chemistry, Physical
Katsuyuki Shizu, Yongxia Ren, Hironori Kaji
Summary: Thermally activated delayed fluorescence (TADF) molecules show promise for durable organic light-emitting diodes. Fast reverse intersystem crossing (RISC) can improve the device lifetime of TADF-based OLEDs. This study investigates the heavy-atom effect on TADF and proposes a molecular design to enhance RISC.
JOURNAL OF PHYSICAL CHEMISTRY A
(2023)
