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Crystalline cyclic(alkyl)(amino)stannylene via transient stannyne

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Science China Chemistry 2024年

作者： xinfeng Wang Chaopeng Hu Zhihao Lu liu Leo liu Department of Chemistry and Research Center for Chemical Biology and Omics Analysis College of Science Southern University of Science and Technology

We demonstrate that a bulky cyclic amino ligand, specifically 1,1,3,3-tetraphenylisoindolinyl, can facilitate the formation of a transient stannyne, endowed with adjacent ambiphilic carbon and tin centers. This stannyne, manifesting carbene-like behavior,engages in an unprecedented sequence of reactions, including Buchner ring expansion, [1,3]sigmatropic, and [1,5]-sigmatropic shifts, culminating in the synthesis of a stable cyclic(alkyl)(amino)stannylene. This compound represents the first tin analogue of the well-known cyclic(alkyl)(amino)carbenes. Both the bonding configuration and the formation process of this stannylene are thoroughly analyzed through quantum chemical computations. Our findings pave the way for further synthesis of unusual main group species using bulky isoindolinyl substituents, emphasizing their potential as a versatile tool in synthetic chemistry.

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Comprehensive understanding on sources of high levels of fine particulate nitro-aromatic compounds at a coastal rural area in northern China

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Journal of Environmental Sciences 2024年第1期135卷 483-494页

作者： Yueru Jiang xinfeng Wang Min Li Yiheng Liang Zhiyi liu Jing Chen Tianyi Guan Jiangshan Mu Yujiao Zhu He Meng Yang Zhou Lan Yao Likun Xue Wenxing Wang Environment Research Institute Shandong UniversityQingdao 266237China Department of Environmental Systems Science Swiss Federal Institute of Technology ZurichZurich 8092Switzerland Department of Water Resources and Drinking Water Swiss Federal Institute of Aquatic Science and TechnologyDuebendorf 8600Switzerland Qingdao Eco-Environment Monitoring Center of Shandong Province Qingdao 266003China College of Oceanic and Atmospheric Sciences Ocean University of ChinaQingdao 266100China School of Environmental and Geographical Sciences Shanghai Normal UniversityShanghai 200234China

Nitro-aromatic compounds(NACs)are among the major components of brown carbon(BrC)in the atmosphere,causing negative impacts on regional climate,air quality,and ecological health.Due to the extensive origins,it is still a challenge to figure out the contributions and originating regions for different sources of atmospheric NACs.Here,field observations on fine particulate NACs were conducted at a coastal rural area in Qingdao,China in the winter of 2018 and 2019.The mean total concentrations of fine particulate nitro-aromatic compounds were 125.0±89.5 and 27.7±21.1 ng/m^(3)in the winter of 2018 and 2019,respectively.Among the measured eleven NACs,nitrophenols and nitrocatechols were the most abundant species.Variation characteristics and correlation analysis showed that humidity and anthropogenic primary emissions had significant influences on the NAC abundances.In this study,two tracing methods of the improved spatial concentration weighted trajectory(SCWT)model and the receptor model of positive matrix factorization(PMF)were combined to comprehensively understand the origins of NACs in fine particles at coastal Qingdao.Four major sources were identified,including coal combustion,biomass burning,vehicle exhaust,and secondary formation.Surprisingly,coal combustion was responsible for about half of the observed nitro-aromatic compounds,followed by biomass burning(~30%).The results by SCWT demonstrated that the coal combustion dominated NACs mainly originated from the Shandong peninsula and the areas to the north and southwest,while those dominated by biomass burning primarily came from local Qingdao and the areas to the west.

关键词： Nitro-aromatic compounds Fine particles Source apportionment Originating region Combustion activities

Degradation of FAK-targeting by proteolytic targeting chimera technology to inhibit the metastasis of hepatocellular carcinoma

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Oncology Research 2024年第4期32卷 679-690页

作者： xinfeng ZHANG SHUANG LI MEIRU SONG YUE CHEN LIANGZHENG CHANG ZHERUI liu HONGYUAN DAI YUTAO WANG GANGQI YANG YUN JIANG YINYING LU The PLA 307 Clinical College of Anhui Medical University The Fifth Clinical Medical College of Anhui Medical UniversityHefei230032China Liver Tumor Diagnosis and Research Center 5th Medical Center of the PLA General HospitalBeijing100039China Department of Infection Diseases Guizhou Medical UniversityGuiyang550025China 4302 Clinical Medical School Peking UniversityBeijingChina Cell and Gene Therapy Innovation Center Beijing Lotuslake BiomedicalScience and Technology ParkBeijing102206China State Key Laboratory of Chemical Oncogenomics and the Institute of Biopharmaceutical and Health Engineering(iBHE) Shenzhen International Graduate SchoolTsinghua UniversityShenzhen518055China

Liver cancer is a prevalent malignant cancer,ranking third in terms of mortality rate.Metastasis and recurrence primarily contribute to the high mortality rate of liver cancer.Hepatocellular carcinoma(HCC)has low expression of focal adhesion kinase(FAK),which increases the risk of metastasis and recurrence.Nevertheless,the efficacy of FAK phosphorylation inhibitors is currently limited.Thus,investigating the mechanisms by which FAK affects HCC metastasis to develop targeted therapies for FAK may present a novel strategy to inhibit HCC metastasis.This study examined the correlation between FAK expression and the prognosis of HCC.Additionally,we explored the impact of FAK degradation on HCC metastasis through wound healing experiments,transwell invasion experiments,and a xenograft tumor model.The expression of proteins related to epithelial-mesenchymal transition(EMT)was measured to elucidate the underlying mechanisms.The results showed that FAK PROTAC can degrade FAK,inhibit the migration and invasion of HCC cells in vitro,and notably decrease the lung metastasis of HCC in vivo.Increased expression of E-cadherin and decreased expression of vimentin indicated that EMT was inhibited.Consequently,degradation of FAK through FAK PROTAC effectively suppressed liver cancer metastasis,holding significant clinical implications for treating liver cancer and developing innovative anti-neoplastic drugs.

关键词： Hepatocellular carcinoma(HCC) Focal adhesion kinase(FAK) Proteolytic targeting chimera technology(PROTAC) Epithelial-mesenchymal transformation(EMT) Metastasis

Phase/size dual controlled 2D semiconductor In_(2)X_(3)(X=S,Se,Te)for saturable absorption modulation

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Nano Research 2022年第6期15卷 5633-5639页

作者： Weibiao Wang Zhexue Chen Xinyu Sui Yueqi Li xinfeng liu Yong Zhang CAS Key Laboratory of Nanosystem and Hierarchical Fabrication CAS Center for Excellence in NanoscienceNational Center for Nanoscience and TechnologyBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China CAS Key Laboratory of Standardization and Measurement for Nanotechnology CAS Center for Excellence in NanoscienceNational Center for Nanoscience and TechnologyBeijing 100190China

The production of two-dimensional nanosheets(2D NSs)with all sizes(1-100 nm)and few(<10)layers is highly desired but far from satisfactory.Herein,we report an all-physical top-down method to produce indium chalcogenide(In2X3(X=S,Se,Te))NSs with wide-range(150-3.0 nm)controlled sizes.The method combines silica-assisted ball-milling and sonication-assisted solvent exfoliation to fabricate multiscale NSs with varying distributions,which are then precisely separated by cascade centrifugation.Multiple characterization techniques reveal that the as-produced In2X3 NSs are intrinsic and defect-free and remainβ-phase during the whole process.The redispersions of In2X3 NSs exhibit prominent excitation wavelength-,solvent-,concentration-,and size-dependent photoluminescence.The NSs-poly(methyl methacrylate)(PMMA)hybrid thin films demonstrate strong size effects in nonlinear saturation absorption.The absolute modulation depths of 35.4%,43.3%,47.2%and saturation intensities of 1.63,1.05,0.83 MW·cm^(−2)(i.e.,163,105,and 83 nJ·cm^(−2))are derived for the In_(2)S_(3),In_(2)Se_(3),and In2Te3 quantum sheets,respectively.Our method paves the way for mass production and full exploration of full-scale 2D NSs.

关键词： semiconductor quantum sheets intrinsic photoluminescence nonlinear saturation absorption

Spectroscopy and carrier dynamics of one-dimensional nanostructures

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Journal of Semiconductors 2022年第12期43卷 12-21页

作者： Yutong Zhang Zhuoya Zhu Shuai Zhang Xianxin Wu Wenna Du xinfeng liu CAS Key Laboratory of Standardization and Measurement for Nanotechnology CAS Center for Excellence in NanoscienceNational Center for Nanoscience and TechnologyBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China

In recent years,one-dimensional(1D)nanomaterials have raised researcher's interest because of their unique structur-al characteristic to generate and confine the optical signal and their promising prospects in photonic applications.In this re-view,we summarized the recent research advances on the spectroscopy and carrier dynamics of 1D nanostructures.First,the condensation and propagation of exciton-polaritons in nanowires(NWs)are introduced.Second,we discussed the properties of 1D photonic crystal(PC)and applications in photonic-plasmonic structures.Third,the observation of topological edge states in 1D topological structures is introduced.Finally,the perspective on the potential opportunities and remaining chal-lenges of 1D nanomaterials is proposed.

关键词： one-dimensional nanostructures carrier dynamics nanowires exciton-polaritons photonic crystals topological struc-tures

Phase-modulated quantum-sized TMDs for extreme saturable absorption

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Nano Research 2023年第4期16卷 5803-5808页

作者： Zhexue Chen Xinyu Sui Zhangqiang Li Yueqi Li xinfeng liu Yong Zhang CAS Key Laboratory of Nanosystem and Hierarchical Fabrication CAS Center for Excellence in NanoscienceNational Center for Nanoscience and TechnologyBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China CAS Key Laboratory of Standardization and Measurement for Nanotechnology CAS Center for Excellence in NanoscienceNational Center for Nanoscience and TechnologyBeijing 100190China

Two-dimensional semiconductors such as transition metal dichalcogenides(TMDs)have attracted much interest in the past decade.Herein,we present an all-physical top-down method for the scalable production of the intrinsic TMD quantum sheets(QSs).The phases of the TMDs(e.g.,2H-MoSe_(2),2H-WSe_(2),and Td-WTe2)remain stable during the transformation from bulk to QSs.However,phase transition(from Td to 2H)is detected in MoTe2.Such phase-modulation by size-reduction has never been reported before.The TMD QSs can be well dispersed in solvents,resulting in remarkable photoluminescence with excitation wavelength-,concentration-,and solvent-dependence.Meanwhile,the TMD QSs can be readily solution-processed into hybrid thin films,which demonstrate exceptional nonlinear saturation absorption(NSA).Notably,2H-MoTe2 QSs in poly(methyl methacrylate)show extremely high NSA performance with(absolute)modulation depth up to 46.6%and saturation intensity down to 0.81 MW·cm^(−2).Our work paves the way towards quantum-sized TMDs.

关键词： transition metal dichalcogenides(TMDs) intrinsic quantum sheets photoluminescence nonlinear saturation absorption

An on-Si directional second harmonic generation amplifier for MoS2/WS2 heterostructure

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Nano Research 2023年第3期16卷 4061-4066页

作者： Jiaxing Du Jianwei Shi Chun Li Qiuyu Shang xinfeng liu Yuan Huang Qing Zhang School of Materials Science and Engineering Peking UniversityBeijing 100871China CAS Key Laboratory of Standardization and Measurement for Nanotechnology CAS Center for Excellence in NanoscienceNational Center for Nanoscience and TechnologyBeijing 100190China Advanced Research Institute of Multidisciplinary Science Beijing Institute of TechnologyBeijing 100081China

Transition metal dichalcogenides(TMD)heterostructure is widely applied for second harmonic generation(SHG)and holds great promises for laser source,nonlinear switch,and optical logic gate.However,for atomically thin TMD heterostructures,low SHG conversion efficiency would occur due to reduction of light-matter interaction length and lack of phase matching.Herein,we demonstrated a facile directional SHG amplifier formed by MoS2/WS2 monolayer heterostructures suspended on a holey SiO_(2)/Si substrate.The SHG enhancement factor reaches more than two orders of magnitude in a wide spectral range from 355 to 470 nm,and the radiation angle is reduced from 38°to 19°indicating higher coherence and better emission directionality.The giant SHG enhancement and directional emission are attributed to the great excitation and emission field concentration induced by a self-formed vertical Fabry-Pérot microcavity.Our discovery gives helpful insights for the development of two-dimensional(2D)nonlinear optical devices.

关键词： two-dimensional(2D)materials transition metal dichalcogenides heterostructure second harmonic generation field enhancement optical microcavity

Lateral quantum confinement regulates charge carrier transfer and biexciton interaction in CdSe/CdSeS core/crown nanoplatelets

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Nano Research 2023年第7期16卷 10420-10428页

作者： Yige Yao Xiaotian Bao Yunke Zhu Xinyu Sui An Hu Peng Bai Shufeng Wang Hong Yang xinfeng liu Yunan Gao State Key Laboratory for Artificial Microstructure and Mesoscopic Physics School of PhysicsPeking UniversityBeijing 100871China CAS Key Laboratory of Standardization and Measurement for Nanotechnology National Center for Nanoscience and TechnologyBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China Frontiers Science Center for Nano-optoelectronics Beijing 100871China Collaborative Innovation Center of Extreme Optics Shanxi UniversityTaiyuan 030006China Peking University Yangtze Delta Institute of Optoelectronics Nantong 226010China Dalian National Laboratory for Clean Energy Dalian 116023China

Charge carrier dynamics essentially determines the performance of various optoelectronic applications of colloidal semiconductor nanocrystals.Among them,two-dimensional nanoplatelets provide new adjustment freedom for their unique core/crown heterostructures.Herein,we demonstrate that by fine-tuning the core size and the lateral quantum confinement,the charge carrier transfer rate from the crown to the core can be varied by one order of magnitude in CdSe/CdSeS core/alloy-crown nanoplatelets.In addition,the transfer can be affected by a carrier blocking mechanism,i.e.,the filled carriers hinder further possible transfer.Furthermore,we found that the biexciton interaction is oppositely affected by quantum confinement and electron delocalization,resulting in a non-monotonic variation of the biexciton binding energy with the emission wavelength.This work provides new observations and insights into the charge carrier transfer dynamics and exciton interactions in colloidal nanoplatelets and will promote their further applications in lasing,display,sensing,etc.

关键词： nanoplatelets core/crown charge carrier transfer ultrafast spectroscopy biexciton

Strong in-plane optical anisotropy in 2D van der Waals antiferromagnet VOCl

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Nano Research 2023年第5期16卷 7481-7488页

作者： Tianle Zhang Jiantao Du Wenjun Wang Keming Wu Shuai Yue xinfeng liu Wanfu Shen Chunguang Hu Minghui Wu Zhe Qu Shengxue Yang Chengbao Jiang School of Materials Science and Engineering Beihang UniversityBeijing 100191China Anhui Key Laboratory of Condensed Matter Physics at Extreme Conditions High Magnetic Field Laboratory Chinese Academy of SciencesHefei 230031China Science Island Branch of Graduate School University of Science and Technology of ChinaHefei 230026China CAS Key Laboratory of Standardization and Measurement for Nanotechnology CAS Center for Excellence in Nanoscience National Center for Nanoscience and Technology Beijing 100190China University of Chinese Academy of Sciences Beijing 100049China State Key Laboratory of Precision Measuring Technology and Instruments Tianjin UniversityTianjin 300072China College of Materials and Chemical Engineering MinJiang UniversityFuzhou 350108China Fujian Key laboratory of Functional marine Sensing materials Minjiang UniversityFuzhou 350108China

Two-dimensional(2D)van der Waals(vdW)magnetic materials with strong in-plane anisotropy can make possible novel applications such as optospintronics and strain sensors.In this work,the strong in-plane optical anisotropy in 2D vdW antiferromagnet VOCl has been systematically investigated.The optical brightness and absorption coefficient exhibit evident periodic variation with the change of incident polarization,unveiling the strong in-plane anisotropic optical absorption.The Raman intensity in this material shows obvious dependence on the polarization angle of incident laser,demonstrating that the phonon properties possess strong in-plane anisotropy.Besides,we have also realized in-situ visualization of in-plane optical reflection anisotropy in this material.Moreover,the strong second harmonic generation(SHG)signal can only be detected when the incident polarization is along specific in-plane crystal orientations,illustrating the presence of strong in-plane nonlinear optical anisotropy.These findings will benefit the applications of VOCl in the field of polarization-dependent electronics and spintronics.

关键词： two-dimensional material vanadium oxide chloride in-plane optical anisotropy linear dichroism nonlinear optics