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General radical difluoromethylation using difluoroacetic anhydride via photoredox catalysis

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Science China chemistry 2024年第8期67卷 2637-2646页

作者： Meng He Yankai Yang Heng Zhang Zhipeng Guan Zhi-Bing Dong Hong Yi Aiwen Lei School of chemistry and Environmental Engineering Wuhan Institute of TechnologyWuhan 430205China College of chemistry and Molecular Sciences and institute for Advanced Studies(IAS) Wuhan UniversityWuhan 430072China

CF_(2)H-containing molecules play pivotal roles in diverse fields from medicinal chemistry to materials science. However, the application of existing CF_(2)H reagents as a source of CF_(2)H radical is limited by their reactivity and preparation. Herein, we develop a simple and general visible-light-catalyzed radical difluoromethylation reaction of alkenes, dienes, and heteroaromatics using commercially available, easy-to-handle, and low-cost difluoroacetic anhydride as the CF_(2)H reagent. This scalable protocol enables the convenient synthesis of a range of CF_(2)H-containing compounds under mild conditions, exhibiting a broad substrate scope and functional group tolerance. Potential applications are further demonstrated by gram-scale synthesis, sunlight experiments, derivatization experiments as well as the synthesis of bioactive molecules.

关键词： radical difluoromethylation alkenes/dienes/heteroaromatics difluoroacetic anhydride photoredox

Suppressing the lattice oxygen diffusion via high-entropy oxide construction towards stabilized acidic water oxidation

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Nano Research 2024年第3期17卷 1107-1113页

作者： Jing Ni Zhaoping Shi Yibo Wang Jiahao Yang Hongxiang Wu Pengbo Wang Kai Li Meiling Xiao Changpeng Liu Wei Xing State Key Laboratory of Electroanalytic chemistry Jilin Province Key Laboratory of Low Carbon Chemistry PowerChangchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China School of Applied chemistry and Engineering University of Science and Technology of ChinaHefei 230026China State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China

The scale-up deployment of ruthenium(Ru)-based oxygen evolution reaction(OER)electrocatalysts in proton exchange membrane water electrolysis(PEMWE)is greatly restricted by the poor *** the lattice-oxygen-mediated mechanism(LOM)has been identified as the major contributor to the fast performance degradation,impeding lattice oxygen diffusion to inhibit lattice oxygen participation is imperative,yet remains challenging due to the lack of efficient ***,we strategically regulate the bonding nature of Ru–O towards suppressed LOM via Ru-based high-entropy oxide(HEO)*** lattice disorder in HEOs is believed to increase migration energy barrier of lattice *** a result,the screened Ti_(23)Nb_(9)Hf_(13)W_(12)Ru_(43)O_(x) exhibits 11.7 times slower lattice oxygen diffusion rate,84%reduction in LOM ratio,and 29 times lifespan extension compared with the state-of-the-art RuO_(2) *** work opens up a feasible avenue to constructing stabilized Ru-based OER catalysts towards scalable application.

关键词： ruthenium-based high-entropy oxide suppressing the lattice oxygen diffusion acidic oxygen evolution reaction

Using vitamin C to improve both performance and stability of n-type organic semiconductors

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Science China Materials 2024年第11期67卷 3755-3756页

作者： Sizhe Liu Xingxin Shao Jun Liu Key Laboratory of Polymer Physics and chemistry Changchun Institute of Applied ChemistryChinese Academy of Sciences School of Applied chemistry and Engineering University of Science and Technology of China

Organic semiconductors(OSCs) have the great advantages of flexibility, light weight, low-cost and large-area processing [1].After intensively studied for several decades, OSCs are now considered to be the most promising candidate materials for next-generation electronic circuits. N-type OSCs are the vital component for the basic electronic element, such as p-n junctions, light-emitting diodes and complementary circuits [2].

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Highly Red Emissive Conjugated Homopolymers Based on Double B←N Bridged Bipyridine Unit

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Chinese Journal of Polymer Science 2024年第8期42卷 1029-1037页

作者： Yu-Yue Gao Kai-Yuan Zhang Shu-Meng Wang Hui Tong Jun Liu State Key Laboratory of Polymer Physics and chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China School of Applied chemistry and Engineering University of Science and Technology of ChinaHefei 230026China

Conjugated homopolymers based on six-member rings,e.g.,polyfluorene,always exhibit blue emission and conjugated homopolymers based on five-member rings,e.g.,polythiophene,can give red emission with low *** this work,we report a series of new conjugated homopolymers based on six-member rings with high-efficiency deep-red *** repeating units of the red light emitting homopolymers are double B←N bridged bipyridine(BNBP)with the boron atoms functionalized with diphenyl,borafluorene,and 2,7-di-tert-butyl-borafluorene groups,*** relationship between the chemical structures and the opto-electronic properties of the monomers and the homopolymers has been systematically *** three polymers emit pure red light(λ_(max)=656 nm)or deep red light(λ_(max)=693 nm)with fluorescence quantum efficiency in solution higher than 60%.The polymers can be used as the emitters in solution-processed organic light-emitting diodes with red emission and decent device *** work indicates a new strategy to design highly efficient light emitting conjugated polymers.

关键词： Conjugated homopolymers Double B←N bridged bipyridine(BNBP) Deep-red emission High fluorescent efficiency

Critical Role of Ethylene-Propylene Block Copolymer in Impact Polypropylene Copolymer

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Chinese Journal of Polymer Science 2024年第3期42卷 344-351,I0007页

作者： Yu-Hui Tang Na Zhang Wei Bao Wei Jiang Yuan Lin Zhao-Hui Su State Key Laboratory of Polymer Physics and chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China School of Applied chemistry and Engineering University of Science and Technology of ChinaHefei 230026China

Ethylene-propylene block copolymer(EbP) is a vital component in impact polypropylene copolymer(IPC), yet its distribution in the multiphase composite material and how it influences the phase structure and the mechanical properties are not well understood. In this work,four IPCs were investigated by atomic force microscopy-infrared(AFM-IR) to assess the phase compositions in situ, based on which in conjunction with the chain microstructure information obtained ex situ the distributions of the copolymer components were derived for each alloy. For the IPCs whose EbP comprises long P and long E segments, the EbP fraction was found to phase separate from the rubber and the PP matrix to form the cores of the disperse particles with the E-P segmented copolymer(EsP). In contrast, in the IPC with EbP composed of long P and short E segments, the EbP fraction formed an outer shell for the rubber particles with the cores comprising the EsP alone, and this IPC, containing a lower E comonomer content than its counterpart, exhibited both better impact resistance and higher flexural modulus. These results clarify how the chain structure of EbP governs the phase morphology in IPC, which in turn impacts the properties of the composite material.

关键词： Impact polypropylene copolymers AFM-IR Ethylene-propylene block copolymers Core-shell rubber particles

Copper-catalyzed asymmetric dearomatizing amination of 2-naphthols:Csp^(2)–N coupling via 1,3-reductive elimination

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Science China chemistry 2024年第8期67卷 2694-2700页

作者： Aying Yihuo Maoping Pu Zheng Tan Jibang Liao Jiuqi Tan Qi-Lin Zhou Xiaohua Liu Xiaoming Feng Key Laboratory of Green chemistry&Technology Ministry of EducationCollege of ChemistrySichuan UniversityChengdu 610064China Key Laboratory and institute of Elemento-Organic chemistry College of Chemistry Frontiers Science Centerfor New Organic MatterNankai UniversityTianjin300071China

An efficient catalytic asymmetric dearomatizing amination of 2-naphthols and phenols catalyzed by N,N′-dioxide-copper(I)complex as a chiral catalyst was presented.A variety of optically activeβ-naphthalenone compounds with a nitrogen-containing quaternary carbon stereocenter were obtained with high yield and enantioselectivity under mild reaction *** studies indicated that this Csp^(2)–N dearomatizing coupling proceeds via 1,3-reductive elimination of phenolate-Cu~Ⅲ-amino intermediate in five-membered ring transition *** origin of enantioselectivity has also been elucidated based on density functional theory calculations.

关键词： asymmetric catalysis amination dearomatization copper catalysis coupling reaction

Dielectric Constant Calculation of Poly(vinylidene fluoride)Based on Finite Field and Density Functional Theory

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Chinese Journal of Polymer Science 2024年第5期42卷 655-662,I0009页

作者： Yong-Zhi Lin Lu-Kun Feng Ya-Dong Li Chao-Fan Chang Cai-Zhen Zhu Ming-Liang Wang Jian Xu College of chemistry and Environmental Engineering Shenzhen UniversityShenzhen518055China Chengdu institute of Organic chemistry Chinese Academy of SciencesChengdu610041China

In this study,we proposed a novel method that integrates density functional theory(DFT)with the finite field method to accurately estimate the polarizability and dielectric constant of *** approach effectively accounts for the influence of electronic and geometric conformation changed on the dielectric *** validated our method using polyethylene(PE)and polytetrafluoroethylene(PTFE)as benchmark materials,and found that it reliably predicted their dielectric ***,we explored the impact of conformation variations in poly(vinylidene fluoride)(PVDF)on its dielectric constant and *** resulting dielectric constants ofα-andγ-PVDF(3.0)showed excellent agreement with crystalline PVDF in *** findings illuminate the relationship between PVDF’s structural properties and its electrical behavior,offering valuable insights for material design and applications.

关键词： Dielectric constant PVDF Finite field DFT

Diatomic Fe-Co catalysts synergistically catalyze oxygen evolution reaction

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Nano Research 2024年第5期17卷 3794-3800页

作者： Tianmi Tang Jingyi Han Zhenlu Wang Xiaodi Niu Jingqi Guan institute of Physical chemistry College of ChemistryJilin UniversityChangchun 130021China College of Food Science and Engineering Jilin UniversityChangchun 130062China

The design of diatomic catalysts with uniformly dispersed metal atoms is expected to improve catalytic performance,which is conducive to the intensive comprehending of the synergistic mechanism between dual-metal sites for the oxygen evolution reaction(OER)at the atomic ***,we design a strategy to immobilize bimetallic Fe-Co atoms onto nitrogen-doped graphene to obtain a diatomic catalyst(DA-FC-NG)with FeN_(3)-CoN_(3) *** DA-FC-NG shows excellent OER activity with a low overpotential(η_(10)=268 mV),which is superior to commercial iridium dioxide *** calculations uncover that the excellent activity of DA-FC-NG is due to the interaction between Fe and Co diatoms,which causes charge rearrangement and induces the adsorption of intermediates on the Fe-O-Co bridge structure,thus improving the catalytic OER *** work is of great significance for the design of highly active diatomic catalysts to replace noble metal catalysts for energy-related applications.

关键词： oxygen evolution reaction diatomic catalyst FeN_(3)-CoN_(3) X-ray absorption spectroscopy(XAS)spectrum theoretical calculation

Introducing urea into tirapazamine derivatives to enhance anticancer therapy

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National Science Review 2024年第4期11卷 245-253页

作者： Yajun Xu Jianlin Lv Chaoying Kong Ya Liu Kun Wang Zhaohui Tang Xuesi Chen Key Laboratory of Polymer Ecomaterials Changchun Institute of Applied ChemistryChinese Academy of Sciences School of Applied chemistry and Engineering University of Science and Technology of China

Tirapazamine（TPZ） has been approved for multiple clinical trials relying on its excellent anticancer ***,as a typical hypoxia-activated prodrug（HAP）,TPZ did not exhibit survival advantages in Phase Ⅲ clinical trials when used in combination therapy due to the insufficient hypoxia levels in patients' *** this study,to improve the therapeutic effects of TPZ,we first introduced urea to synthesize a series of urea-containing derivatives of *** urea-containing TPZ derivatives showed increased hypoxic cytotoxicity（9.51-30.85-fold） compared with TPZ,while maintaining hypoxic ***,one of these derivatives,showed 20-fold higher cytotoxicity than TPZ while maintaining a similar hypoxic cytotoxicity *** highly efficiently deliver TPZP to the tumors and reduce its side effects on healthy tissues,we further prepared TPZP into a nanodrug with fibrin-targeting ability:***4-NPs,a vascular disrupting agent,was used to increase the fibrin level within tumors and exacerbate tumor *** being combined with CA4-NPs,FT11-TPZP-NPs can accumulate in the hypoxia-aggravated tumors and activate sufficiently to kill tumor *** a single-dose treatment,FT11-TPZP-NPs+CA4-NPs showed a high inhibition rate of 98.1% against CT26 tumor models with an initial volume of ～480 mm3and four out of six tumors were completely eliminated;it thereby exerted a significant antitumor *** study provides a new strategy for improving the therapeutic effect of TPZ and other HAPs in anticancer therapy.

关键词： tirapazamine vascular disrupting agent hypoxia-activated prodrug combretastatin A4 urea