Nanoscale metal organic frameworks(NMOFs)have been widely reported in biomedical field for their unique porous structure and tunable multifunctionality.However,when administrated in vivo,the protein corona will be for...Nanoscale metal organic frameworks(NMOFs)have been widely reported in biomedical field for their unique porous structure and tunable multifunctionality.However,when administrated in vivo,the protein corona will be formed on the surface of NMOFs,significantly affecting their biodistribution,pharmacokinetics and drug release.Few studies paid attention to the protein corona formation process and its influencing factors of NMOFs.As a well-established strategy for altering structure features of NMOFs,the organic ligand modification may have effect on the protein corona formation process,which is to be investigated.In this study,the zirconium(Zr)-based UIO66 was chosen as model NMOFs,the organic ligand of which was modified with amino group(-NH_(2))or carboxyl group(-COOH)to synthesize UIO66-NH_(2)and UIO66-2COOH,respectively.Bovine serum albumin(BSA)was chosen as model protein to investigate the protein corona formation process of NMOFs.The current results showed that the-COOH modification remarkably enhanced the BSA adsorption on NMOFs while-NH_(2)slightly decreased the protein binding affinity.These differences may be ascribed to the two different dominate protein corona formation modes,i.e.,surface coating mode and porous embedded mode.The protein corona formation did not affect the crystal phase of NMOFs but increased the content ofα-helix of BSA.Ultimately,upon protein corona formation,the cellular uptake of NMOFs was significantly affected.We believe our study will provide a new research paradigm to the design and applications of NMOFs.展开更多
In this work,we describe bis-cyclometalated iridium complexes with efficient deep-red luminescence.Two different cyclometalating(C^N)ligands-1-phenylisoquinoline(piq)and 2-(2-pyridyl)benzothiophene(btp)-are used with ...In this work,we describe bis-cyclometalated iridium complexes with efficient deep-red luminescence.Two different cyclometalating(C^N)ligands-1-phenylisoquinoline(piq)and 2-(2-pyridyl)benzothiophene(btp)-are used with five strongπ-donating ancillary ligands(L^X)to furnish a suite of nine new complexes with the general formula Ir(C^N)_(2)(L^X).Improvements in deep-red photoluminescence quantum yields were accomplished by the incorporation of sterically encumbering substituents onto the ancillary ligand,which can enhance the radiative rate constant(k_(r))and/or reduce the non-radiative rate constant(k_(nr)).Five of the complexes were characterized by X-ray crystallography,and all of them were investigated by in-depth spectroscopic and electrochemical measurements.展开更多
The poor stability of halide perovskite nanocrystals(NCs)has severely hindered future practical application.Herein,we proposed a facile and effective ligand modification route to synthesize stable CsPbBr_(3) nanocryst...The poor stability of halide perovskite nanocrystals(NCs)has severely hindered future practical application.Herein,we proposed a facile and effective ligand modification route to synthesize stable CsPbBr_(3) nanocrystals by introducing a double-terminal ligand,namely 4,4'-Azobis(4-cyanovalericacid)(CA),to replace the conventional oleic acid(OA)ligand at room temperature.The as-synthesized CsPbBr_(3)-CA not only possesses high photoluminescence quantum yield(72%)related to the reduced trap defects,but also shows significantly improved stability exposure to water,ethanol,light,and/or heat benefiting from the CA ligand anchored to NC surfaces tightly.The photoluminescence intensity of CsPbBr_(3)-CA maintains about 80%and 75%of its initial emission intensity after immersed in water or ethanol for 360 min,respectively,whereas that of the CsPbBr_(3)-OA was quenched completely within a few minutes.Moreover,an all-inorganic white light-emitting diode(LED)covered 126%National Television System Committee(NTSC)standard and 92%Rec.2020 standard was fabricated by combining the green CsPbBr_(3)-CA and commercial red-emitting K2SiF6:Mn4+(KSF)phosphors onto a blue LED chip.Thus,the presented work initiates the development of the room temperature preparation of high quality CsPbBr_(3) and shows prospect for next-generation displays.展开更多
All-inorganic CsPbBr_(3) perovskite quantum dots(QDs)have received great attention in white light emission because of their outstanding properties.However,their practical application is hindered by poor stability.Here...All-inorganic CsPbBr_(3) perovskite quantum dots(QDs)have received great attention in white light emission because of their outstanding properties.However,their practical application is hindered by poor stability.Herein,we propose a simple strategy to synthesize excellent stability and efficient emission of CsPbBr_(3) QDs by using 2-hexyldecanoic acid(DA)as a ligand to replace the regular oleic acid(OA)ligand.Thanks to the strong binding energy between DA ligand and QDs,the modified QDs not only show a high photoluminescence quantum yield(PLQY)of 96%but also exhibit high stability against ethanol and water.Thereby warm white light-emitting diodes(WLEDs)are constructed by combining lig-and modified CsPbBr_(3) QDs with red AgInZnS QDs on blue emitting InGaN chips,exhibiting a color rendering index of 93,a power efficiency of 64.8 lm/W,a CIE coordinate of(0.44,0.42)and correlated color temperature value of 3018 K.In ad-dition,WLEDs based on ligand modified CsPbBr_(3) QDs also exhibit better thermal performance than that of WLEDs based on the regular CsPbBr_(3) QDs.The combination of improved efficiency and better thermal stability with high color quality indicates that the modified CsPbBr_(3) QDs are ideal for WLEDs application.展开更多
Chiral metal-organic clusters(cMOCs)are characterized by diverse chiral origins,tunable luminescence,and multifunctionality.Among them,chiral aluminum oxo clusters(AlOCs)exhibit unique advantages in terms of resource ...Chiral metal-organic clusters(cMOCs)are characterized by diverse chiral origins,tunable luminescence,and multifunctionality.Among them,chiral aluminum oxo clusters(AlOCs)exhibit unique advantages in terms of resource sustainability and environmental friendliness compared to other cluster materials.Nevertheless,the simultaneous achievement of precise enantiomeric control and optical response within AlOCs remains a critical challenge to be addressed in the field.Herein,we achieve precise control over the transition from chirality to circularly polarized luminescence properties in AlOCs by leveraging their highly flexible and modifiable coordination surfaces through a stepwise ligand functionalization strategy.We employed the Al2cluster as a platform with programmable surface coordination sites and introduced classical chiral L/D-valine molecules.We successfully constructed four pairs of alcohol-coordinated pure chiral enantiomers(AlOC-189-L/D-MeOH,EtOH,PrOH,and PDO).Absolute helical structures can be identified in the supramolecular architectures of clusters,achieving unambiguous chirality transfer from chiral ligands to chiral clusters and further to absolute helical superstructures.Hierarchical ligand modification,endowed with a top-down design paradigm,offers a rational and feasible route to cluster functionalization.Based on the excellent replaceability of the Al_(2)cluster's surface coordination sites,we achieved chiral-luminescent bifunctional coupling by partially substituting the chiral ligands withπ-conjugated naphthyl-based luminophores(HNA/HNN),yielding two new classes of enantiomers(AlOC-190-L/D-HNA and AlOC-190-L/D-HNN)exhibiting bright yellow-green photoluminescence(PL).DFT calculations reveal that this is attributed to a ligand-to-ligand charge transfer(LLCT)luminescence mechanism.Notably,AlOC-190-L/D-HNN exhibited promising circularly polarized luminescence(CPL)activity via the synergy between chiral induction from L/D-valine ligands and intermolecular charge transfer of the HNN ligands.This work not only highlights the highly designable coordination chemistry of AlOC-enabling on-demand integration of specific functionalities through modular ligand substitution-but also establishes a novel"ligand editing"paradigm for developing multifunctional chiral optical materials.展开更多
Heteroleptic stannylenes,featuring pendant hemilabile iminophosphorane functionalities and kinetically stabilizing terphenyl ligands,were synthesized straightforwardly through formal C-H activation.Subsequently,they w...Heteroleptic stannylenes,featuring pendant hemilabile iminophosphorane functionalities and kinetically stabilizing terphenyl ligands,were synthesized straightforwardly through formal C-H activation.Subsequently,they were investigated for their ability to activate ammonia through N-H bond scission.By combining synthetic modifications of the ancillary ligand framework and computational analyses,detailed insights into the mechanism of NH_(3) activation by these systems were obtained,highlighting an activation pathway at tin without a change in oxidation state.Additionally,an observed by-product during these studies underscores the non-innocence of a lithium salt in the synthesis of the stannylene starting materials,providing access to a novel lithium stannylenoid.展开更多
Inhaled nanoparticles(NPs)need to penetrate the bronchial mucosa to deliver drug payloads deeply in the lung for amplified local therapy.However,the bronchial mucociliary barrier eliminates NPs rapidly,which considera...Inhaled nanoparticles(NPs)need to penetrate the bronchial mucosa to deliver drug payloads deeply in the lung for amplified local therapy.However,the bronchial mucociliary barrier eliminates NPs rapidly,which considerably limits their mucosal penetration.In this study,we find that surface ligand modification and stiffness adjustment of NPs contribute to the significantly enhanced bronchial mucosal absorption and pulmonary retention of inhaled drugs.We utilize neonatal Fc receptor ligand(FcBP)to modify the rationally designed low stiffness NPs(Soft-NP)and high stiffness NPs(Stiff-NP)to target bronchial mucosa.In an acute lung inflammation rat model,after intranasal administration with dexamethasone-loaded NPs,Stiff-NP endowed with FcBP displays superior therapeutic effects.The in vitro data demonstrate that the promotion effect of FcBP to bronchial mucosal absorption of Stiff-NP dominates over Soft-NP.This could be attributed to the higher affinity between ligand-receptor when incorporating FcBP on the Stiff-NP surface.Meanwhile,high stiffness modulates more actin filaments aggregation to mediate endocytosis,along with strengthened Ca2+signal to enhance exocytosis.Conclusively,we highlight that FcBP-modified NPs with higher stiffness would be a potential pulmonary drug delivery system.展开更多
Electroreduction of nitrate(NO_(3)-)to ammonia(NH_(3))is an environmentally friendly route for NH_(3)production,serving as an appealing alternative to the Haber-Bosch process.Recently,various noble metal-based electro...Electroreduction of nitrate(NO_(3)-)to ammonia(NH_(3))is an environmentally friendly route for NH_(3)production,serving as an appealing alternative to the Haber-Bosch process.Recently,various noble metal-based electrocatalysts have been reported for electroreduction of NO_(3)-.However,the application of pure metal electrocatalysts is still limited by unsatisfactory performance,owing to the weak adsorption of nitrogen-containing intermediates on the surface of pure metal electrocatalysts.In this work,we report thiol ligand-modified Au nanoparticles as the effective electrocatalysts toward electroreduction of NO_(3)-.Specifically,three mercaptobenzoic acid(MBA)isomers,thiosalicylic acid(ortho-MBA),3-mercaptobenzoic acid(meta-MBA),and 4-mercaptobenzoic acid(para-MBA),were employed to modify the surface of the Au nanocatalyst.During the NO_(3)-electroreduction,para-MBA modified Au(denoted as para-Au/C)displayed the highest catalytic activity among these Au-based catalysts.At-1.0 V versus reversible hydrogen electrode(vs RHE),para-Au/C exhibited a partial current density for NH_(3)of 472.2 mA cm^(-2),which was 1.7 times that of the pristine Au catalyst.Meanwhile,the Faradaic efficiency(FE)for NH_(3)reached 98.7%at-1.0 V vs RHE for para-Au/C.The modification of para-MBA significantly improved the intrinsic activity of the Au/C catalyst,thus accelerating the kinetics of NO_(3)-reduction and giving rise to a high NH_(3)yield rate of para-Au/C.展开更多
Luminescence is one of the most important properties for metal nanoclusters;however,clearly revealing its origin remains challenging.The different luminescence properties of the two prototypical 8e nanoclusters Au_(11...Luminescence is one of the most important properties for metal nanoclusters;however,clearly revealing its origin remains challenging.The different luminescence properties of the two prototypical 8e nanoclusters Au_(11)and Au_(13)remain elusive—Au_(11)is always nonluminescent,whereas Au_(13)is luminescent.In this work,by using a designed unique aromatic ligand(quinoline-2-thiol),we obtained new atomically precise phosphine-thiolate-protected neutral Au_(11)-SH and cationic Au_(13)-SH.In comparison with the classic phosphine-halide-protected Au_(11)-Cl and Au_(13)-Cl,the Cl-to-thiol alteration triggered room-temperature luminescence of the Au_(11)core and dramatically modulated that of the Au_(13)core.Ultrafast ultraviolet/infrared(UV/IR)spectroscopy,which is sensitive to organic aromatic groups,together with ultrafast transient absorption(TA)spectroscopy unprecedently revealed a relaxation process from the ligand to core state affecting the dynamics in excited states and some critical intermediate states favouring efficient room-temperature emission of these nanoclusters.This work provides some new insights into the origin of photoluminescence of metal nanoclusters and opens an avenue to modulate the dynamics of their excited states using aromatic ligands,which would have direct applications in lighting,light harvesting,and photocatalysis.展开更多
It is still a formidable challenge to simultaneously switch single-chain magnet(SCM)behavior via ligand modification and light irradiation in the field of molecular spintronics.Herein,we present a ligandbridged layer{...It is still a formidable challenge to simultaneously switch single-chain magnet(SCM)behavior via ligand modification and light irradiation in the field of molecular spintronics.Herein,we present a ligandbridged layer{[pzTpFe(CN)3]4Co2(Bib)4}·3H2O(1;pzTp,tetra-kis(1-pyrazolyl)borate;Bib,1,4-bis-(1Himidazol-1-yl)benzene)and a well-isolated double chain{[pzTpFe(CN)3]2Co(Bpi)2}·CH3CN·4H2O(2;Bpi,1-Biphenyl-4-yl-1H-imidazole)that display reversible metal-to-metal charge transfer(MMCT)between FeIII LS(μ-CN)CoII HS(μ-NC)FeIII LS(LS,low spin;HS,high spin)and FeIII LS(μ-CN)CoIII LS(μ-NC)FeII LS linkages under alternating irradiation with 808 and 532 nm lasers.The bidirectional light irradiations induces significant changes in anisotropy and intrachain magnetic interactions,resulting in the on/off switching of SCM behavior with observable hysteresis loops by 808 and 532 nm light irradiations for both compounds.Because of the ligand modification,the SCM property of 2 with the monodentate ligand is greatly improved with a correlation length increased to 83,which is the largest correlation length among all reported light actuated SCMs.Furthermore,the influence of ligand modification on their thermally induced MMCT is also discussed.This study provides a rational approach for the swift and reversible control of SCM behavior via ligand modified and light induced MMCT,which is crucial to the future technological demand for high-density data storage and processing.展开更多
As a kind of two-dimensional(2D)nanostructured materials,metal oxide nanosheets(MONS)are attractive and promising humidity sensing materials due to their considerable surface area,good charge carrier transportation,an...As a kind of two-dimensional(2D)nanostructured materials,metal oxide nanosheets(MONS)are attractive and promising humidity sensing materials due to their considerable surface area,good charge carrier transportation,and designable surface functional groups properties.Nevertheless,the ultra-thin MONS modified with active functional groups for humidity sensing are still rare.As a proof of concept,the atomically thin TiO_(2)nanosheets with high surface area and electron-donating amino groups are prepared by a structure-maintained post-ligand modification strategy.The fabricated TiO_(2)-based sensors demonstrate superior humidity sensing performance with high response,short response time,narrow hysteresis,and ultra-low theoretical limit of detection of about 15 ppm.Additionally,the possible mechanism is proposed from the AC complex impedance measurements and DC instantaneous reverse polarity experiments.This work provides a possible path for developing the high-performance 2D nanostructured metal oxides-based humidity materials through the surface chemical method.展开更多
Incorporating functional ligands and biodegradable bonds into biocompatible low-molecular-weight(LMW)polymers,such as 1.8 kDa poly(ethylenimine)(PEI1.8 k),is a common strategy to improve the properties of LMW polymers...Incorporating functional ligands and biodegradable bonds into biocompatible low-molecular-weight(LMW)polymers,such as 1.8 kDa poly(ethylenimine)(PEI1.8 k),is a common strategy to improve the properties of LMW polymers including biosafety and delivery efficacy.This study demonstrates the hypothesis that introducing different functional ligands and linked reductive disulfides in PEI 1.8k will achieve superior siRNA transfection efficiency.By incorporating PEI-X(X represents cholesterol(Ch),heptafluorobutyric anhydride(HFBA,F)and 4-carboxyphenylboronic acid(PBA))functional ligands into PEI 1.8k and subsequently crosslinking with each other via disulfide bond links,reductive-responsive PEI-X-SS-X-PEI copolymers were constructed to enhance the cellular transfection via the synergistic effect of the high affinity of Ch,F and PBA to cell membranes and the disulfide reduction triggered intracellular disassembly of micelles and subsequent siRNA release.Extraordinarily,ternary Ch-SS-F-SS-PBA micelles exhibited the strongest siRNA transfection efficiencies in in vitro cell experiments and in vivo animal experiments due to the coordination of enhanced serum stability,promoted cell uptake and endosomal escape,and cell targeting ability.This strategy of constructed multifunctional polymer here we called"building-block crosslinking"showed a simple and smart way to synthesize new materials.Also this strategy of constructing ligands-directed reduction-sensitive micelles improves the transfection efficiency of LMW PEI and provides a valuable insight to develop novel gene delivery systems.展开更多
基金the project grants from the National Natural Science Foundation of China (No. 82104070)the Key Areas Research and Development Program of Guangdong Province (No. 2019B020204002)the Fundamental Research Funds for the Central Universities (No. 21621012)
文摘Nanoscale metal organic frameworks(NMOFs)have been widely reported in biomedical field for their unique porous structure and tunable multifunctionality.However,when administrated in vivo,the protein corona will be formed on the surface of NMOFs,significantly affecting their biodistribution,pharmacokinetics and drug release.Few studies paid attention to the protein corona formation process and its influencing factors of NMOFs.As a well-established strategy for altering structure features of NMOFs,the organic ligand modification may have effect on the protein corona formation process,which is to be investigated.In this study,the zirconium(Zr)-based UIO66 was chosen as model NMOFs,the organic ligand of which was modified with amino group(-NH_(2))or carboxyl group(-COOH)to synthesize UIO66-NH_(2)and UIO66-2COOH,respectively.Bovine serum albumin(BSA)was chosen as model protein to investigate the protein corona formation process of NMOFs.The current results showed that the-COOH modification remarkably enhanced the BSA adsorption on NMOFs while-NH_(2)slightly decreased the protein binding affinity.These differences may be ascribed to the two different dominate protein corona formation modes,i.e.,surface coating mode and porous embedded mode.The protein corona formation did not affect the crystal phase of NMOFs but increased the content ofα-helix of BSA.Ultimately,upon protein corona formation,the cellular uptake of NMOFs was significantly affected.We believe our study will provide a new research paradigm to the design and applications of NMOFs.
基金the National Science Foundation(CHE-1846831)the Welch Foundation(grant no.E-1887)for funding this research.
文摘In this work,we describe bis-cyclometalated iridium complexes with efficient deep-red luminescence.Two different cyclometalating(C^N)ligands-1-phenylisoquinoline(piq)and 2-(2-pyridyl)benzothiophene(btp)-are used with five strongπ-donating ancillary ligands(L^X)to furnish a suite of nine new complexes with the general formula Ir(C^N)_(2)(L^X).Improvements in deep-red photoluminescence quantum yields were accomplished by the incorporation of sterically encumbering substituents onto the ancillary ligand,which can enhance the radiative rate constant(k_(r))and/or reduce the non-radiative rate constant(k_(nr)).Five of the complexes were characterized by X-ray crystallography,and all of them were investigated by in-depth spectroscopic and electrochemical measurements.
基金supported by the National Natural Science Foundation of China(Nos.61775060,61275100,61761136006,61790583,and 61874043).
文摘The poor stability of halide perovskite nanocrystals(NCs)has severely hindered future practical application.Herein,we proposed a facile and effective ligand modification route to synthesize stable CsPbBr_(3) nanocrystals by introducing a double-terminal ligand,namely 4,4'-Azobis(4-cyanovalericacid)(CA),to replace the conventional oleic acid(OA)ligand at room temperature.The as-synthesized CsPbBr_(3)-CA not only possesses high photoluminescence quantum yield(72%)related to the reduced trap defects,but also shows significantly improved stability exposure to water,ethanol,light,and/or heat benefiting from the CA ligand anchored to NC surfaces tightly.The photoluminescence intensity of CsPbBr_(3)-CA maintains about 80%and 75%of its initial emission intensity after immersed in water or ethanol for 360 min,respectively,whereas that of the CsPbBr_(3)-OA was quenched completely within a few minutes.Moreover,an all-inorganic white light-emitting diode(LED)covered 126%National Television System Committee(NTSC)standard and 92%Rec.2020 standard was fabricated by combining the green CsPbBr_(3)-CA and commercial red-emitting K2SiF6:Mn4+(KSF)phosphors onto a blue LED chip.Thus,the presented work initiates the development of the room temperature preparation of high quality CsPbBr_(3) and shows prospect for next-generation displays.
基金supported by the National Natural Science Foundation of China(NSFC)(Grant Nos.11974063,11904156)Postdoctoral Science Foundation of China(No.2019M653336).The calcu-lations were done at the Center for Computational Science and Engineering of Southern University of Science and Technology(SUSTech).
文摘All-inorganic CsPbBr_(3) perovskite quantum dots(QDs)have received great attention in white light emission because of their outstanding properties.However,their practical application is hindered by poor stability.Herein,we propose a simple strategy to synthesize excellent stability and efficient emission of CsPbBr_(3) QDs by using 2-hexyldecanoic acid(DA)as a ligand to replace the regular oleic acid(OA)ligand.Thanks to the strong binding energy between DA ligand and QDs,the modified QDs not only show a high photoluminescence quantum yield(PLQY)of 96%but also exhibit high stability against ethanol and water.Thereby warm white light-emitting diodes(WLEDs)are constructed by combining lig-and modified CsPbBr_(3) QDs with red AgInZnS QDs on blue emitting InGaN chips,exhibiting a color rendering index of 93,a power efficiency of 64.8 lm/W,a CIE coordinate of(0.44,0.42)and correlated color temperature value of 3018 K.In ad-dition,WLEDs based on ligand modified CsPbBr_(3) QDs also exhibit better thermal performance than that of WLEDs based on the regular CsPbBr_(3) QDs.The combination of improved efficiency and better thermal stability with high color quality indicates that the modified CsPbBr_(3) QDs are ideal for WLEDs application.
基金supported by the National Natural Science Foundation of China(22371278,92261108,92061104)the Natural Science Foundation of Fujian Province(2021J06035)+1 种基金the Fujian Provincial Department of Science and Technology(#2023T3081)the Youth Innovation Promotion Association Chinese Academy of Sciences(Y2021081).
文摘Chiral metal-organic clusters(cMOCs)are characterized by diverse chiral origins,tunable luminescence,and multifunctionality.Among them,chiral aluminum oxo clusters(AlOCs)exhibit unique advantages in terms of resource sustainability and environmental friendliness compared to other cluster materials.Nevertheless,the simultaneous achievement of precise enantiomeric control and optical response within AlOCs remains a critical challenge to be addressed in the field.Herein,we achieve precise control over the transition from chirality to circularly polarized luminescence properties in AlOCs by leveraging their highly flexible and modifiable coordination surfaces through a stepwise ligand functionalization strategy.We employed the Al2cluster as a platform with programmable surface coordination sites and introduced classical chiral L/D-valine molecules.We successfully constructed four pairs of alcohol-coordinated pure chiral enantiomers(AlOC-189-L/D-MeOH,EtOH,PrOH,and PDO).Absolute helical structures can be identified in the supramolecular architectures of clusters,achieving unambiguous chirality transfer from chiral ligands to chiral clusters and further to absolute helical superstructures.Hierarchical ligand modification,endowed with a top-down design paradigm,offers a rational and feasible route to cluster functionalization.Based on the excellent replaceability of the Al_(2)cluster's surface coordination sites,we achieved chiral-luminescent bifunctional coupling by partially substituting the chiral ligands withπ-conjugated naphthyl-based luminophores(HNA/HNN),yielding two new classes of enantiomers(AlOC-190-L/D-HNA and AlOC-190-L/D-HNN)exhibiting bright yellow-green photoluminescence(PL).DFT calculations reveal that this is attributed to a ligand-to-ligand charge transfer(LLCT)luminescence mechanism.Notably,AlOC-190-L/D-HNN exhibited promising circularly polarized luminescence(CPL)activity via the synergy between chiral induction from L/D-valine ligands and intermolecular charge transfer of the HNN ligands.This work not only highlights the highly designable coordination chemistry of AlOC-enabling on-demand integration of specific functionalities through modular ligand substitution-but also establishes a novel"ligand editing"paradigm for developing multifunctional chiral optical materials.
文摘Heteroleptic stannylenes,featuring pendant hemilabile iminophosphorane functionalities and kinetically stabilizing terphenyl ligands,were synthesized straightforwardly through formal C-H activation.Subsequently,they were investigated for their ability to activate ammonia through N-H bond scission.By combining synthetic modifications of the ancillary ligand framework and computational analyses,detailed insights into the mechanism of NH_(3) activation by these systems were obtained,highlighting an activation pathway at tin without a change in oxidation state.Additionally,an observed by-product during these studies underscores the non-innocence of a lithium salt in the synthesis of the stannylene starting materials,providing access to a novel lithium stannylenoid.
基金support from the National Science Foundation for Distinguished Yong Scholars(81625023)the National Natural Science Foundation of China(81872818).
文摘Inhaled nanoparticles(NPs)need to penetrate the bronchial mucosa to deliver drug payloads deeply in the lung for amplified local therapy.However,the bronchial mucociliary barrier eliminates NPs rapidly,which considerably limits their mucosal penetration.In this study,we find that surface ligand modification and stiffness adjustment of NPs contribute to the significantly enhanced bronchial mucosal absorption and pulmonary retention of inhaled drugs.We utilize neonatal Fc receptor ligand(FcBP)to modify the rationally designed low stiffness NPs(Soft-NP)and high stiffness NPs(Stiff-NP)to target bronchial mucosa.In an acute lung inflammation rat model,after intranasal administration with dexamethasone-loaded NPs,Stiff-NP endowed with FcBP displays superior therapeutic effects.The in vitro data demonstrate that the promotion effect of FcBP to bronchial mucosal absorption of Stiff-NP dominates over Soft-NP.This could be attributed to the higher affinity between ligand-receptor when incorporating FcBP on the Stiff-NP surface.Meanwhile,high stiffness modulates more actin filaments aggregation to mediate endocytosis,along with strengthened Ca2+signal to enhance exocytosis.Conclusively,we highlight that FcBP-modified NPs with higher stiffness would be a potential pulmonary drug delivery system.
基金This work was supported by Strategic Priority Research Program of the Chinese Academy of Sciences(XDB0450401)National Key Research and Development Program of China(2021YFA1500500 and 2019YFA0405600)+3 种基金NSFC(22209161,22209163,92061111,22322901,22221003,and 22250007)CAS Project for Young Scientists in Basic Research(YSBR-051 and YSBR-022)National Science Fund for Distinguished Young Scholars(21925204),China Postdoctoral Program for Innovative Talents(BX20200324)Fundamental Research Funds for the Central Universities.J.Z.acknowledges support from the Tencent Foundation through the XPLORER PRIZE.The authors acknowledge support from Prof.Chao Ma and Mr.Sunpei Hu in conducting the microscopic characterization,and Dr.Hong Wu in the DFT computations.This work was partially carried out at the Instruments Center for Physical Science,University of Science and Technology of China.This work was also partially carried out at the USTC Center for Micro and Nanoscale Research and Fabrication。
文摘Electroreduction of nitrate(NO_(3)-)to ammonia(NH_(3))is an environmentally friendly route for NH_(3)production,serving as an appealing alternative to the Haber-Bosch process.Recently,various noble metal-based electrocatalysts have been reported for electroreduction of NO_(3)-.However,the application of pure metal electrocatalysts is still limited by unsatisfactory performance,owing to the weak adsorption of nitrogen-containing intermediates on the surface of pure metal electrocatalysts.In this work,we report thiol ligand-modified Au nanoparticles as the effective electrocatalysts toward electroreduction of NO_(3)-.Specifically,three mercaptobenzoic acid(MBA)isomers,thiosalicylic acid(ortho-MBA),3-mercaptobenzoic acid(meta-MBA),and 4-mercaptobenzoic acid(para-MBA),were employed to modify the surface of the Au nanocatalyst.During the NO_(3)-electroreduction,para-MBA modified Au(denoted as para-Au/C)displayed the highest catalytic activity among these Au-based catalysts.At-1.0 V versus reversible hydrogen electrode(vs RHE),para-Au/C exhibited a partial current density for NH_(3)of 472.2 mA cm^(-2),which was 1.7 times that of the pristine Au catalyst.Meanwhile,the Faradaic efficiency(FE)for NH_(3)reached 98.7%at-1.0 V vs RHE for para-Au/C.The modification of para-MBA significantly improved the intrinsic activity of the Au/C catalyst,thus accelerating the kinetics of NO_(3)-reduction and giving rise to a high NH_(3)yield rate of para-Au/C.
基金supported by the National Natural Science Foundation of China(Nos.U21A20277,92061201,21825106,21975065,12174012,22203006,and 22103072)Zhengzhou University.
文摘Luminescence is one of the most important properties for metal nanoclusters;however,clearly revealing its origin remains challenging.The different luminescence properties of the two prototypical 8e nanoclusters Au_(11)and Au_(13)remain elusive—Au_(11)is always nonluminescent,whereas Au_(13)is luminescent.In this work,by using a designed unique aromatic ligand(quinoline-2-thiol),we obtained new atomically precise phosphine-thiolate-protected neutral Au_(11)-SH and cationic Au_(13)-SH.In comparison with the classic phosphine-halide-protected Au_(11)-Cl and Au_(13)-Cl,the Cl-to-thiol alteration triggered room-temperature luminescence of the Au_(11)core and dramatically modulated that of the Au_(13)core.Ultrafast ultraviolet/infrared(UV/IR)spectroscopy,which is sensitive to organic aromatic groups,together with ultrafast transient absorption(TA)spectroscopy unprecedently revealed a relaxation process from the ligand to core state affecting the dynamics in excited states and some critical intermediate states favouring efficient room-temperature emission of these nanoclusters.This work provides some new insights into the origin of photoluminescence of metal nanoclusters and opens an avenue to modulate the dynamics of their excited states using aromatic ligands,which would have direct applications in lighting,light harvesting,and photocatalysis.
基金supported by the National Natural Science Foundation of China(grant nos.21901133,22171155,22035003,91856124,22025101,91961114,21871039,and 22173015)China National Postdoctoral Program for Innovative Talents(grant no.BX20180147).
文摘It is still a formidable challenge to simultaneously switch single-chain magnet(SCM)behavior via ligand modification and light irradiation in the field of molecular spintronics.Herein,we present a ligandbridged layer{[pzTpFe(CN)3]4Co2(Bib)4}·3H2O(1;pzTp,tetra-kis(1-pyrazolyl)borate;Bib,1,4-bis-(1Himidazol-1-yl)benzene)and a well-isolated double chain{[pzTpFe(CN)3]2Co(Bpi)2}·CH3CN·4H2O(2;Bpi,1-Biphenyl-4-yl-1H-imidazole)that display reversible metal-to-metal charge transfer(MMCT)between FeIII LS(μ-CN)CoII HS(μ-NC)FeIII LS(LS,low spin;HS,high spin)and FeIII LS(μ-CN)CoIII LS(μ-NC)FeII LS linkages under alternating irradiation with 808 and 532 nm lasers.The bidirectional light irradiations induces significant changes in anisotropy and intrachain magnetic interactions,resulting in the on/off switching of SCM behavior with observable hysteresis loops by 808 and 532 nm light irradiations for both compounds.Because of the ligand modification,the SCM property of 2 with the monodentate ligand is greatly improved with a correlation length increased to 83,which is the largest correlation length among all reported light actuated SCMs.Furthermore,the influence of ligand modification on their thermally induced MMCT is also discussed.This study provides a rational approach for the swift and reversible control of SCM behavior via ligand modified and light induced MMCT,which is crucial to the future technological demand for high-density data storage and processing.
基金supported by the National Natural Science Foundation of China(21905280,22171263,91961115,22175176 and 21975254)National Natural Science Foundation of Fujian(2021J02017 and 2020J01109)Youth Innovation Promotion Association CAS。
文摘As a kind of two-dimensional(2D)nanostructured materials,metal oxide nanosheets(MONS)are attractive and promising humidity sensing materials due to their considerable surface area,good charge carrier transportation,and designable surface functional groups properties.Nevertheless,the ultra-thin MONS modified with active functional groups for humidity sensing are still rare.As a proof of concept,the atomically thin TiO_(2)nanosheets with high surface area and electron-donating amino groups are prepared by a structure-maintained post-ligand modification strategy.The fabricated TiO_(2)-based sensors demonstrate superior humidity sensing performance with high response,short response time,narrow hysteresis,and ultra-low theoretical limit of detection of about 15 ppm.Additionally,the possible mechanism is proposed from the AC complex impedance measurements and DC instantaneous reverse polarity experiments.This work provides a possible path for developing the high-performance 2D nanostructured metal oxides-based humidity materials through the surface chemical method.
基金supported by the National Natural Science Foundation of China(81903556)the Natural Science Fund for Colleges and Universities in Jiangsu Province(19KJB350004)supported by the National Health and Medical Research Council(NHMRC)Early Career Fellowship(1112258)of Australia。
文摘Incorporating functional ligands and biodegradable bonds into biocompatible low-molecular-weight(LMW)polymers,such as 1.8 kDa poly(ethylenimine)(PEI1.8 k),is a common strategy to improve the properties of LMW polymers including biosafety and delivery efficacy.This study demonstrates the hypothesis that introducing different functional ligands and linked reductive disulfides in PEI 1.8k will achieve superior siRNA transfection efficiency.By incorporating PEI-X(X represents cholesterol(Ch),heptafluorobutyric anhydride(HFBA,F)and 4-carboxyphenylboronic acid(PBA))functional ligands into PEI 1.8k and subsequently crosslinking with each other via disulfide bond links,reductive-responsive PEI-X-SS-X-PEI copolymers were constructed to enhance the cellular transfection via the synergistic effect of the high affinity of Ch,F and PBA to cell membranes and the disulfide reduction triggered intracellular disassembly of micelles and subsequent siRNA release.Extraordinarily,ternary Ch-SS-F-SS-PBA micelles exhibited the strongest siRNA transfection efficiencies in in vitro cell experiments and in vivo animal experiments due to the coordination of enhanced serum stability,promoted cell uptake and endosomal escape,and cell targeting ability.This strategy of constructed multifunctional polymer here we called"building-block crosslinking"showed a simple and smart way to synthesize new materials.Also this strategy of constructing ligands-directed reduction-sensitive micelles improves the transfection efficiency of LMW PEI and provides a valuable insight to develop novel gene delivery systems.
