A three-dimensional flexible organic framework FOF-1 has been synthesized from the condensation of a tetratopic acylhydrazine and a rigid 4,4-diphenyl-4,4-bipyridinium dialdehyde in water through the quantitative form...A three-dimensional flexible organic framework FOF-1 has been synthesized from the condensation of a tetratopic acylhydrazine and a rigid 4,4-diphenyl-4,4-bipyridinium dialdehyde in water through the quantitative formation of hydrazone bond. FOF-1 is further applied to construct a polycatenane framework FOF-pc-1 through the quantitative cucurbit[7]uril encapsulation for the diphenylbipyridinium subunits of the framework by making use of the dynamic nature of the hydrazone bond in water. The bipyridinium subunits in both frameworks can be reduced their radical cation counterparts to produce conjugated radical cation-linked dynamic organic frameworks rc-FOF-1 or rc-FOF-pc-1. Polycatenation is revealed to enhance the stability of the dynamic frameworks in water, whereas depolycatenation can be reached for both FOF-pc-1 and rc-FOF-pc-1 by using a ferrocene vip to form a more stable complex with CB[7].展开更多
Solvothermal reaction of Zn(NO_(3))_(2)and a bifunctional ligand 4-(3,5-dimethyl-1H-pyrazol-4-yl)benzoic acid(H_(2)mpba)using benzene as template gave a two-fold interpenetrated porous framework[Zn_(2)(Hmpba)_(2)(mpba...Solvothermal reaction of Zn(NO_(3))_(2)and a bifunctional ligand 4-(3,5-dimethyl-1H-pyrazol-4-yl)benzoic acid(H_(2)mpba)using benzene as template gave a two-fold interpenetrated porous framework[Zn_(2)(Hmpba)_(2)(mpba)]·2C_(6)H_(6)(1·C_(6)H_(6)or MCF-54),which displayed single-crystal to single-crystal(SCSC)structural transformations upon activation and adsorption of methanol,toluene and cyclohexane.Singlecrystal structural analysis and computational simulations demonstrated that compound 1 possesses adaptive pores toward various shapes or arrangements of vips.Using silicone rubber as binder,microcrystalline powders of 1 were coated on the inner surface of a capillary column for gas chromatography,which displayed high separation performances and/or abnormal separation sequences for similar benzene homologues.By virtue of the large loading amount of adsorbent,the column shows extra-large columncapacity,being almost 300 times larger than that of common commercial capillary columns,leading to good selectivities and resolutions even in the presence of large amount of interferents.展开更多
We have entered the age of renewable energy revolution.Hence,energy-dense all-solid-state lithium metal batteries are now being actively researched as one of the most promising energy storage systems.However,they have...We have entered the age of renewable energy revolution.Hence,energy-dense all-solid-state lithium metal batteries are now being actively researched as one of the most promising energy storage systems.However,they have not yet been a silver bullet due to the dendrite formation and interfacial issue.Here,we introduce the hybrid polymer electrolyte via a novel solvent-free strategy as well as utilize a polymerization and gelation effect of cyanoethyl polyvinyl alcohol to achieve superior electrochemical performance.The hybrid polymer electrolyte,using cyanoethyl polyvinyl alcohol,demonstrates a stable artificial solid electrolyte interface layer,which suppresses the continuous decomposition of Li salts.Importantly,we also present the lithium-graphite composite anode to reach the super-highenergy-density anode materials.Taken together,these advancements represent a significant stride toward addressing the challenges associated with all-solid-state lithium metal batteries.展开更多
Predictive design of vip-responsive frameworks on the molecular level is still a major challenge for experimental and theoretical chemists.The isoreticular approach is one of the most promising approaches for design...Predictive design of vip-responsive frameworks on the molecular level is still a major challenge for experimental and theoretical chemists.The isoreticular approach is one of the most promising approaches for designing MOFs with desired textural properties and framework topology.In this work we successfully applied the isoreticular approach for the design of the new flexible frameworks DUT-180 and DUT-190,constructed by square planar or octahedral metal nodes and a tetracarboxylate ligand.The flexibility mechanism in DUT-190 was explored using in situ PXRD and NMR in parallel to physisorption of subcritical gases such as nitrogen(77 K),carbon dioxide(195 K)and xenon(206 K).Methane physisorption experiments,conducted in a broad temperature range indicate a softening of the DUT-190 framework compared to its analogue DUT-13.These experimental and computational findings can be used as a roadmap for discovery of new flexible frameworks with desired micromechanical properties.展开更多
Photocatalytic CO_(2) reduction into valuable chemical fuels is a highly desirable subject in the field of photosynthesis.Nevertheless,the performance of most current photocatalytic CO_(2) reduction catalysts remains ...Photocatalytic CO_(2) reduction into valuable chemical fuels is a highly desirable subject in the field of photosynthesis.Nevertheless,the performance of most current photocatalytic CO_(2) reduction catalysts remains a significant challenge for practical applications.In this study,we present the achievement of anchoring of nickel(Ni)metal sites onto a flexible and stable covalent organic framework(COF-Tp-Azo)for photocatalytic CO_(2) reduction.It is noteworthy that the flexibility of the framework plays a crucial role in improving the adsorption of carbon dioxide,as it minimizes steric hindrance.On incorporating varying amounts of metal active species into the COFs,the resultant COF-Tp-Azo-Nix demonstrates a pronounced influence on the catalytic activity.Specifically,COF-Tp-Azo-Ni0.33 exhibits a high CO production rate of 9742.5μmol g^(−1) h^(−1) with a selectivity as high as 98.8%under visible light irradiation,representing the highest production and selectivity for reported nickel-based COFs.The photoelectrochemical experiments demonstrate that the covalent bonding between Ni^(2+)and COF-Tp-Azo inhibits the recombination of photogenerated charge carriers and facilitates electron migration,thereby enhancing catalytic activity.Additionally,theoretical calculations reveal that the low energy barrier in both the absorption process between Ni-COF-Tp-Azo and CO_(2),as well as the protonation process for Ni-^(*)COO,contributes to the superior catalytic activity of COF-Tp-Azo-Nix.This work opens a new pathway to high-performance catalysts for CO_(2) photoreduction.展开更多
The precise control of the crystal morphology of metal-organic frameworks(MOFs)enables optimization of its adsorptive properties,as well as enables better integration within functional devices.However,the influence of...The precise control of the crystal morphology of metal-organic frameworks(MOFs)enables optimization of its adsorptive properties,as well as enables better integration within functional devices.However,the influence of such modifications on the dynamic properties of flexible MOFs is poorly understood Here,we report the synthesis of a series of Cu_(2)(bdc)_(2)(bpy)(bdc^(2-)=1,4-benzenedicarboxylate;bpy=4,4,-bipyridine)crystals having an unusual picture frame-like morphology that results from a restriction in the quantity of bpy pillars added to the reaction mixture during the intercalation of the Cu_(2)(bdc)_(2)(MeOH)_(2)layers.The width of the frames is found to correlate with the quantity of bpy,and importantly,causes the dynamic properties of the resulting Cu_(2)(bdc)_(2)(bpy)material to vary between rigid,elastic,and shape memory modes.In all,the results demonstrate the potential for the properties of MOFs to be optimized via subtle manipulations in the crystal morphology rather than changes in the overall material composition.展开更多
Bioinspired membranes are advantageous in capturing the osmotic energy.However,the conventional hybrid membranes possess low harvesting power density due to their low interfacial ionic transport efficiency and high in...Bioinspired membranes are advantageous in capturing the osmotic energy.However,the conventional hybrid membranes possess low harvesting power density due to their low interfacial ionic transport efficiency and high internal resistance.Herein,a new kind of hybrid membranes consisting of porous polymer and flexible organic frameworks was developed.The 3D porous framework enables ions to flux with high efficiency at the polymer-framework interface,resulting in high osmotic energy harvesting efficiency.By systematically screening the pore size of the frameworks,the output power density as high as 5.7 W/m^(2) was achieved under 50-fold KCl salinity gradient.展开更多
Structural flexibility is an intriguing characteristic observed in materials that endows them with dynamic properties,allowing for intelligent adaptation and deformation in response to varying conditions.Covalent orga...Structural flexibility is an intriguing characteristic observed in materials that endows them with dynamic properties,allowing for intelligent adaptation and deformation in response to varying conditions.Covalent organic frameworks(COFs),a promising class of crystalline porous polymers,have garnered significant attention due to their unique features,including well-ordered,predesignable,and tunable structures,as well as their light-weighted nature and high thermal/chemical stability.Integrating flexibility into COFs offers a captivating pathway for developing advanced materials with dynamic properties and versatile functionalities.The flexible COF field is currently experiencing rapid expansion,and there is a growing need for systematic review articles that offer a comprehensive overview of the developments in this domain.In this mini-review,we delve into the factors that contribute to structural flexibility in COFs from the point of structural design.We summarize and categorize various modes of achieving flexibility across different dimensions,and discuss the potential applications of flexible COFs in vapor/gas adsorption,sensing,and smart membrane separations;further,we highlight their prospects and future research advancement.展开更多
Solvothermal reactions of MnCl2with pyridylbenzoic acids gave three-dimensional metal-carboxylate frameworks(MCFs),named MCF-34,MCF-43,and MCF-44,based on one-dimensional Mn-carboxylate chains.The crystal structure,st...Solvothermal reactions of MnCl2with pyridylbenzoic acids gave three-dimensional metal-carboxylate frameworks(MCFs),named MCF-34,MCF-43,and MCF-44,based on one-dimensional Mn-carboxylate chains.The crystal structure,stability,porosity,and framework flexibility of the new compound MCF-44 were studied in detail and compared with its analogs.Depending on their shapes and the bridging angles of the ligands,these compounds possess different network connectivities and porosities.Considering the pyridylbenzote ligands and Mn(II)ions as,respectively,3-and 6-connected nodes,they resemble either the anatase(ant)or rutile(rtl)polymorph of TiO2.Variable-temperature single-crystal X-ray diffraction studies revealed large thermal expansion coefficients for these compounds,which are probably related to the relatively flexible edge-sharing polyhedral structure of their Mn-carboxylate chains.Interestingly,the new compound MCF-44,with its highly porous rtl structure exhibits the largest thermal expansion coefficienct among the coordination polymers reported so far.展开更多
Reactions of[M(NH_(3))_(2)]OH(M=Ag and Cu)and 4-(1H-pyrazol-4-yl)pyridine(Hpypz),using p-xylene(C_(8)H_(10))as the template,gave isomorphous two-dimensional porous metal azolate frameworks[Ag_(2)(pypz)_(2)]·0.5C_...Reactions of[M(NH_(3))_(2)]OH(M=Ag and Cu)and 4-(1H-pyrazol-4-yl)pyridine(Hpypz),using p-xylene(C_(8)H_(10))as the template,gave isomorphous two-dimensional porous metal azolate frameworks[Ag_(2)(pypz)_(2)]·0.5C_(8)H_(10)(MAF-36(Ag),1·g)and[Cu_(2)(pypz)_(2)]·0.5C_(8)H_(10)(MAF-36(Cu),2·g).Powder and singlecrystal X-ray diffraction studies showed that,upon vip removal,1·g transformed into a three-dimensional nonporous framework[Ag_(6)(pypz)_(6)](1’),while 2·g can retain its porous two-dimensional structure.Depending on the metal ion,framework flexibility/rigidity,and/or porosity,1·g and 2·g,as well as their vip-free derivatives,showed distinctly different photoluminescence and vip-responsive behaviors.展开更多
基金financially supported by the National Natural Science Foundation of China (Nos. 21890732, 21890730 and21921003)。
文摘A three-dimensional flexible organic framework FOF-1 has been synthesized from the condensation of a tetratopic acylhydrazine and a rigid 4,4-diphenyl-4,4-bipyridinium dialdehyde in water through the quantitative formation of hydrazone bond. FOF-1 is further applied to construct a polycatenane framework FOF-pc-1 through the quantitative cucurbit[7]uril encapsulation for the diphenylbipyridinium subunits of the framework by making use of the dynamic nature of the hydrazone bond in water. The bipyridinium subunits in both frameworks can be reduced their radical cation counterparts to produce conjugated radical cation-linked dynamic organic frameworks rc-FOF-1 or rc-FOF-pc-1. Polycatenation is revealed to enhance the stability of the dynamic frameworks in water, whereas depolycatenation can be reached for both FOF-pc-1 and rc-FOF-pc-1 by using a ferrocene vip to form a more stable complex with CB[7].
基金supported by the“973 Project”(2014CB845602)the NSFC(21473260,91622109 and 21731007)+3 种基金the Guangdong Pearl River Talents Program(2017BT01C161)the National Key Scientific Instrument and Equipment Development Project(2013YQ24051107)C.-T.He is thankful to the National Postdoctoral Program for Innovative Talents(BX201600195)the China Postdoctoral Science Foundation(2017M620397).
文摘Solvothermal reaction of Zn(NO_(3))_(2)and a bifunctional ligand 4-(3,5-dimethyl-1H-pyrazol-4-yl)benzoic acid(H_(2)mpba)using benzene as template gave a two-fold interpenetrated porous framework[Zn_(2)(Hmpba)_(2)(mpba)]·2C_(6)H_(6)(1·C_(6)H_(6)or MCF-54),which displayed single-crystal to single-crystal(SCSC)structural transformations upon activation and adsorption of methanol,toluene and cyclohexane.Singlecrystal structural analysis and computational simulations demonstrated that compound 1 possesses adaptive pores toward various shapes or arrangements of vips.Using silicone rubber as binder,microcrystalline powders of 1 were coated on the inner surface of a capillary column for gas chromatography,which displayed high separation performances and/or abnormal separation sequences for similar benzene homologues.By virtue of the large loading amount of adsorbent,the column shows extra-large columncapacity,being almost 300 times larger than that of common commercial capillary columns,leading to good selectivities and resolutions even in the presence of large amount of interferents.
基金supported by the Technology Innovation Program(RS-2023-00256202,Development of MLCB design and manufacturing process technology for board mounting)funded by the Ministry of Trade,Industry&Energy(MOTIE,Korea).
文摘We have entered the age of renewable energy revolution.Hence,energy-dense all-solid-state lithium metal batteries are now being actively researched as one of the most promising energy storage systems.However,they have not yet been a silver bullet due to the dendrite formation and interfacial issue.Here,we introduce the hybrid polymer electrolyte via a novel solvent-free strategy as well as utilize a polymerization and gelation effect of cyanoethyl polyvinyl alcohol to achieve superior electrochemical performance.The hybrid polymer electrolyte,using cyanoethyl polyvinyl alcohol,demonstrates a stable artificial solid electrolyte interface layer,which suppresses the continuous decomposition of Li salts.Importantly,we also present the lithium-graphite composite anode to reach the super-highenergy-density anode materials.Taken together,these advancements represent a significant stride toward addressing the challenges associated with all-solid-state lithium metal batteries.
基金the European Research Council(ERC)under the European Union’s Horizon 2020 research and innovation program(grant agreement No.742743)support by the Federal Ministry of Education and Research(Project TIMESWITCH No 05K21OD1)support by the Graduate Academy of the Technical University Dresden.E.B.and S.K.gratefully acknowledge financial support from DFG(FOR 2433).
文摘Predictive design of vip-responsive frameworks on the molecular level is still a major challenge for experimental and theoretical chemists.The isoreticular approach is one of the most promising approaches for designing MOFs with desired textural properties and framework topology.In this work we successfully applied the isoreticular approach for the design of the new flexible frameworks DUT-180 and DUT-190,constructed by square planar or octahedral metal nodes and a tetracarboxylate ligand.The flexibility mechanism in DUT-190 was explored using in situ PXRD and NMR in parallel to physisorption of subcritical gases such as nitrogen(77 K),carbon dioxide(195 K)and xenon(206 K).Methane physisorption experiments,conducted in a broad temperature range indicate a softening of the DUT-190 framework compared to its analogue DUT-13.These experimental and computational findings can be used as a roadmap for discovery of new flexible frameworks with desired micromechanical properties.
基金the National Natural Science Foundation of China(Grant No.51604155)the Foundation of the Jiangsu Education Committee(20KJB150006)for financial supportsupported by the outstanding scientific and technological innovation teams in the colleges and univer-sities of Jiangsu province.
文摘Photocatalytic CO_(2) reduction into valuable chemical fuels is a highly desirable subject in the field of photosynthesis.Nevertheless,the performance of most current photocatalytic CO_(2) reduction catalysts remains a significant challenge for practical applications.In this study,we present the achievement of anchoring of nickel(Ni)metal sites onto a flexible and stable covalent organic framework(COF-Tp-Azo)for photocatalytic CO_(2) reduction.It is noteworthy that the flexibility of the framework plays a crucial role in improving the adsorption of carbon dioxide,as it minimizes steric hindrance.On incorporating varying amounts of metal active species into the COFs,the resultant COF-Tp-Azo-Nix demonstrates a pronounced influence on the catalytic activity.Specifically,COF-Tp-Azo-Ni0.33 exhibits a high CO production rate of 9742.5μmol g^(−1) h^(−1) with a selectivity as high as 98.8%under visible light irradiation,representing the highest production and selectivity for reported nickel-based COFs.The photoelectrochemical experiments demonstrate that the covalent bonding between Ni^(2+)and COF-Tp-Azo inhibits the recombination of photogenerated charge carriers and facilitates electron migration,thereby enhancing catalytic activity.Additionally,theoretical calculations reveal that the low energy barrier in both the absorption process between Ni-COF-Tp-Azo and CO_(2),as well as the protonation process for Ni-^(*)COO,contributes to the superior catalytic activity of COF-Tp-Azo-Nix.This work opens a new pathway to high-performance catalysts for CO_(2) photoreduction.
基金the Australian Research Council for a Discovery Early Career Research Award(No.D E I60100306)a Discovery Project(No.DP190101402)the Centre for Advanced Nanomaterials at the University of Adelaide for financial support.
文摘The precise control of the crystal morphology of metal-organic frameworks(MOFs)enables optimization of its adsorptive properties,as well as enables better integration within functional devices.However,the influence of such modifications on the dynamic properties of flexible MOFs is poorly understood Here,we report the synthesis of a series of Cu_(2)(bdc)_(2)(bpy)(bdc^(2-)=1,4-benzenedicarboxylate;bpy=4,4,-bipyridine)crystals having an unusual picture frame-like morphology that results from a restriction in the quantity of bpy pillars added to the reaction mixture during the intercalation of the Cu_(2)(bdc)_(2)(MeOH)_(2)layers.The width of the frames is found to correlate with the quantity of bpy,and importantly,causes the dynamic properties of the resulting Cu_(2)(bdc)_(2)(bpy)material to vary between rigid,elastic,and shape memory modes.In all,the results demonstrate the potential for the properties of MOFs to be optimized via subtle manipulations in the crystal morphology rather than changes in the overall material composition.
基金Financial support from the National R&D Program of China(Grant No.2017YFA0206901)the National Natural Science Foundation of China(NSFC,Grant Nos.21725202,21921003,and 21971046)the Science and Technology Commission of Shanghai Municipality(STCSM,Grant No.22JC1403700)is gratefully acknowledged。
文摘Bioinspired membranes are advantageous in capturing the osmotic energy.However,the conventional hybrid membranes possess low harvesting power density due to their low interfacial ionic transport efficiency and high internal resistance.Herein,a new kind of hybrid membranes consisting of porous polymer and flexible organic frameworks was developed.The 3D porous framework enables ions to flux with high efficiency at the polymer-framework interface,resulting in high osmotic energy harvesting efficiency.By systematically screening the pore size of the frameworks,the output power density as high as 5.7 W/m^(2) was achieved under 50-fold KCl salinity gradient.
基金supported by the Ministry of Education,Singapore(grant nos.MOE2019-T2-1-093 and MOET2EP10122-0002)the Energy Market Authority of Singapore(grant no.EMA-EP009-SEGC-020)+1 种基金the Agency for Science,Technology,and Research,Singapore(grant nos.U2102d2004 and U2102d2012)the National Research Foundation,Singapore(grant nos.NRF-CRP26-2021RS-0002 and NRF-NRFI08-2022-0008).
文摘Structural flexibility is an intriguing characteristic observed in materials that endows them with dynamic properties,allowing for intelligent adaptation and deformation in response to varying conditions.Covalent organic frameworks(COFs),a promising class of crystalline porous polymers,have garnered significant attention due to their unique features,including well-ordered,predesignable,and tunable structures,as well as their light-weighted nature and high thermal/chemical stability.Integrating flexibility into COFs offers a captivating pathway for developing advanced materials with dynamic properties and versatile functionalities.The flexible COF field is currently experiencing rapid expansion,and there is a growing need for systematic review articles that offer a comprehensive overview of the developments in this domain.In this mini-review,we delve into the factors that contribute to structural flexibility in COFs from the point of structural design.We summarize and categorize various modes of achieving flexibility across different dimensions,and discuss the potential applications of flexible COFs in vapor/gas adsorption,sensing,and smart membrane separations;further,we highlight their prospects and future research advancement.
基金supported by the National Basic Research Progrem of China(2012CB821706)the National Natural Science Foundation of China(21121061 and 21225105)
文摘Solvothermal reactions of MnCl2with pyridylbenzoic acids gave three-dimensional metal-carboxylate frameworks(MCFs),named MCF-34,MCF-43,and MCF-44,based on one-dimensional Mn-carboxylate chains.The crystal structure,stability,porosity,and framework flexibility of the new compound MCF-44 were studied in detail and compared with its analogs.Depending on their shapes and the bridging angles of the ligands,these compounds possess different network connectivities and porosities.Considering the pyridylbenzote ligands and Mn(II)ions as,respectively,3-and 6-connected nodes,they resemble either the anatase(ant)or rutile(rtl)polymorph of TiO2.Variable-temperature single-crystal X-ray diffraction studies revealed large thermal expansion coefficients for these compounds,which are probably related to the relatively flexible edge-sharing polyhedral structure of their Mn-carboxylate chains.Interestingly,the new compound MCF-44,with its highly porous rtl structure exhibits the largest thermal expansion coefficienct among the coordination polymers reported so far.
基金supported by the“973 Project”(2012CB821706)NSFC(21121061 and 21225105).
文摘Reactions of[M(NH_(3))_(2)]OH(M=Ag and Cu)and 4-(1H-pyrazol-4-yl)pyridine(Hpypz),using p-xylene(C_(8)H_(10))as the template,gave isomorphous two-dimensional porous metal azolate frameworks[Ag_(2)(pypz)_(2)]·0.5C_(8)H_(10)(MAF-36(Ag),1·g)and[Cu_(2)(pypz)_(2)]·0.5C_(8)H_(10)(MAF-36(Cu),2·g).Powder and singlecrystal X-ray diffraction studies showed that,upon vip removal,1·g transformed into a three-dimensional nonporous framework[Ag_(6)(pypz)_(6)](1’),while 2·g can retain its porous two-dimensional structure.Depending on the metal ion,framework flexibility/rigidity,and/or porosity,1·g and 2·g,as well as their vip-free derivatives,showed distinctly different photoluminescence and vip-responsive behaviors.
