The combination of a zirconium metal-organic cluster and a Keggin type polyoxotungstate into a compound of the formula[Zr_(6)(μ_(3)-O)_(4)(μ_(3)-OH)_(4)(μ-OOCC_(6)H_(5))_(8)(H_(2)O)_(8)][SiW_(12)O_(4)0]led to a che...The combination of a zirconium metal-organic cluster and a Keggin type polyoxotungstate into a compound of the formula[Zr_(6)(μ_(3)-O)_(4)(μ_(3)-OH)_(4)(μ-OOCC_(6)H_(5))_(8)(H_(2)O)_(8)][SiW_(12)O_(4)0]led to a chemically and photochemically stable material in which a synergistic effect between the metal-organic cluster and the polyoxometalate allows marked enhancement of the photochemical activity of the single ionic components toward the photooxidation of dyes.展开更多
Three different precursors of boron-aqua and glycerol solutions of boric acid and ethanol solution of trimethyl borate were used for the preparation of organic–inorganic advanced materials. The films and bulk materia...Three different precursors of boron-aqua and glycerol solutions of boric acid and ethanol solution of trimethyl borate were used for the preparation of organic–inorganic advanced materials. The films and bulk materials samples were heat treated at 100, 400, 800？C for 2 h. The hybrid samples were stable and transparent until 100？C. The further increase of temperature to 400？C led to destruction of samples, and at 800？C they were molten. The structural changes during the pyrolysis were studied by Fourier transform infrared spectroscopy, differential thermal analysis, and X-ray diffraction. Details of surface morphology were observed by scanning electron microscopy. The obtained BO_3 and BO_4 groups were identified in the molten materials after pyrolysis. The quantities and order of borate structural units as well as residual carbon in the networks depended on boron precursor type. PVA/PEG/B_2O_3 hybrid materials were proved to be appropriate precursors for synthesizing borate and carboborate glass and carbon/borate glass nanocomposites. To access the impact of the experimental conditions on the structural changes of the nanocomposites, cluster analysis of the IR-spectral data was used as a classification method.展开更多
Construction of metal-organic polyhedral clusters is promising and challenging in science due to their highly symmetric structures and potential application to molecular devices.In this work,three neutral nanocages of...Construction of metal-organic polyhedral clusters is promising and challenging in science due to their highly symmetric structures and potential application to molecular devices.In this work,three neutral nanocages of{[Fe(Tp)(CN)_(3)]_(24)[M(H_(2)O)_(2)]_(6)[M(L)(H_(2)O)]12}·xH_(2)O(1-Fe,2-Ni,and 3-Mn for M=Fe,Ni,Mn and x=6,2,4,respectively;Tp=hydrotris(pyrazolyl)borate and L=pyridine-4-carboxylate)were prepared through the assembly of[Fe(Tp)(CN)_(3)]^(-)with Fe^(II),Ni^(II),or Mn^(II) ions and pyridine-4-carboxaldehyde,which was oxidized to pyridine-4-carboxylic acid during the reactions.Single crystal structure analyses revealed that each cage has the same core structure of an Archimedean polyhedra,the pseudo-rhombicuboctahedron.Elemental analyses and magnetic and spectroscopic measurements were performed to determine the oxidation and spin states of the composite metal ions,demonstrating that their electron configurations can be altered by changing the metal ions and deprotonating the auxiliary ligands.In addition,magnetic studies indicated that the metal ions were ferromagnetically coupled within the cage structure.These clusters exhibited magnetocaloric effects(MCEs)with the entropy changes of 11.55 J kg^(-1) K^(-1) for 1-Fe,5.84 J kg^(-1) K^(-1) for 2-Ni,and 19.84 J kg^(-1) K^(-1) for 3-Mn at 3 K and 8.5 T,and 3-Mn is among the family of high-performance 3d-metal-based magnetic coolants.展开更多
It is crucial to design highly selective and cost-effective materials for efficient CO_(2) uptake and the desirable transformation of CO_(2) into fuels or high-value chemical products.Here,we synthesize a series of tr...It is crucial to design highly selective and cost-effective materials for efficient CO_(2) uptake and the desirable transformation of CO_(2) into fuels or high-value chemical products.Here,we synthesize a series of trinuclear indium cluster-based metal-organic frameworks(MOFs)for highly efficient CO_(2) capture and electrocatalytic conversion into C1 products.By adjusting the metal type and replacing the ligand,the mixed metal-based MOF InCo-ABDBC-HIN shows high CO_(2) capture performance(101.7 cm^(3) g^(-1) at 273 K under low pressure)and superior activity(a maximum FEC1 of 81.5% at -2.2 V vs.Ag/Ag^(+))for electrocatalytic CO_(2) reduction in organic electrolytes due to its modified electronic structure.Theoretical calculations suggest that the substitution of In by Co significantly modified the electronic structure of In-based clusters,which provides rich unpaired electrons for the CO_(2)RR and enhances the charge transfer efficiency.This work provides a specially coordinated trinuclear indium cluster-based MOF and sheds new light on the precise structural design of both CO_(2) adsorbents and electrocatalysts for efficient CO_(2) reduction.展开更多
Two novel porous MOFs,[Cu_(2)Cl(TZI)(H_(2)O)_(3)]·4DMA(compound 1)and[Cu_(2)(TZI)(OH)(DMF)]·DMF·H_(2)O(compound 2)(H_(3)TZI=5-(tetrazol-5-yl)isophthalic acid,DMA=N,N-dimethylacetamide,and DMF=N,N-dimeth...Two novel porous MOFs,[Cu_(2)Cl(TZI)(H_(2)O)_(3)]·4DMA(compound 1)and[Cu_(2)(TZI)(OH)(DMF)]·DMF·H_(2)O(compound 2)(H_(3)TZI=5-(tetrazol-5-yl)isophthalic acid,DMA=N,N-dimethylacetamide,and DMF=N,N-dimethylformamide),have been successfully synthesized using the same ligand consisting of isophthalate and tetrazolate groups and CuCl_(2)·2H_(2)O through the secondary building unit(SBU)strategy.Both compounds are constructed from copper cluster-based SBUs.Compound 1 is made up of two different cages based on a Cu paddlewheel and rare-reported double-crown like hexanuclear Cu cluster.In this SBU,the Cu atom adopts a five-coordination in a trigonal bipyramidal configuration,which is very rare in reported MOFs.Moreover,compound 1 with dual functionalities of open metal sites(OMSs)and N-rich Lewis basic sites(LBSs)exhibits good CO_(2) adsorption(92 cm^(3) g^(-1) at 273 K)and high-effect separation ability(9.6 for CO_(2)/CH_(4)=0.5/0.5 under 1 bar at 298 K).展开更多
基金financial support from the Basque Government(IT1291-19)from the University of the Basque Country(predoctoral fellowships for J.P.C.and M.P.I.:PIF17/51 and PIF18/175)+1 种基金from the Spanish Ministry of Science and Innovation(PID2019-108028GB-C21)Technical and human support provided by SGIker(UPV/EHU,MICINN,GV/EJ,and ESF)is also acknowledged.
文摘The combination of a zirconium metal-organic cluster and a Keggin type polyoxotungstate into a compound of the formula[Zr_(6)(μ_(3)-O)_(4)(μ_(3)-OH)_(4)(μ-OOCC_(6)H_(5))_(8)(H_(2)O)_(8)][SiW_(12)O_(4)0]led to a chemically and photochemically stable material in which a synergistic effect between the metal-organic cluster and the polyoxometalate allows marked enhancement of the photochemical activity of the single ionic components toward the photooxidation of dyes.
基金supported by the Spanish Ministry of Education and Science (Project CTM2012-39183)the Generalitat de Catalunya (Grup Consolidat 2014SGR1017)support of H2020 program of the European Union (project Materials Networking)
文摘Three different precursors of boron-aqua and glycerol solutions of boric acid and ethanol solution of trimethyl borate were used for the preparation of organic–inorganic advanced materials. The films and bulk materials samples were heat treated at 100, 400, 800？C for 2 h. The hybrid samples were stable and transparent until 100？C. The further increase of temperature to 400？C led to destruction of samples, and at 800？C they were molten. The structural changes during the pyrolysis were studied by Fourier transform infrared spectroscopy, differential thermal analysis, and X-ray diffraction. Details of surface morphology were observed by scanning electron microscopy. The obtained BO_3 and BO_4 groups were identified in the molten materials after pyrolysis. The quantities and order of borate structural units as well as residual carbon in the networks depended on boron precursor type. PVA/PEG/B_2O_3 hybrid materials were proved to be appropriate precursors for synthesizing borate and carboborate glass and carbon/borate glass nanocomposites. To access the impact of the experimental conditions on the structural changes of the nanocomposites, cluster analysis of the IR-spectral data was used as a classification method.
基金supported by the National Natural Science Foundation of China(22025101,91961114,21871039,21801037 and 22071017the Fundamental Research Funds for Central University,China.
文摘Construction of metal-organic polyhedral clusters is promising and challenging in science due to their highly symmetric structures and potential application to molecular devices.In this work,three neutral nanocages of{[Fe(Tp)(CN)_(3)]_(24)[M(H_(2)O)_(2)]_(6)[M(L)(H_(2)O)]12}·xH_(2)O(1-Fe,2-Ni,and 3-Mn for M=Fe,Ni,Mn and x=6,2,4,respectively;Tp=hydrotris(pyrazolyl)borate and L=pyridine-4-carboxylate)were prepared through the assembly of[Fe(Tp)(CN)_(3)]^(-)with Fe^(II),Ni^(II),or Mn^(II) ions and pyridine-4-carboxaldehyde,which was oxidized to pyridine-4-carboxylic acid during the reactions.Single crystal structure analyses revealed that each cage has the same core structure of an Archimedean polyhedra,the pseudo-rhombicuboctahedron.Elemental analyses and magnetic and spectroscopic measurements were performed to determine the oxidation and spin states of the composite metal ions,demonstrating that their electron configurations can be altered by changing the metal ions and deprotonating the auxiliary ligands.In addition,magnetic studies indicated that the metal ions were ferromagnetically coupled within the cage structure.These clusters exhibited magnetocaloric effects(MCEs)with the entropy changes of 11.55 J kg^(-1) K^(-1) for 1-Fe,5.84 J kg^(-1) K^(-1) for 2-Ni,and 19.84 J kg^(-1) K^(-1) for 3-Mn at 3 K and 8.5 T,and 3-Mn is among the family of high-performance 3d-metal-based magnetic coolants.
基金supported by the National Natural Science Foundation of China(22071140 and 21901151)the Natural Science Foundation of Shaanxi Province(2021JLM-20)+1 种基金the China Postdoctoral Science Foundation(2022TQ0200)the Fundamental Research Funds for the Central Universities(GK202101002).
文摘It is crucial to design highly selective and cost-effective materials for efficient CO_(2) uptake and the desirable transformation of CO_(2) into fuels or high-value chemical products.Here,we synthesize a series of trinuclear indium cluster-based metal-organic frameworks(MOFs)for highly efficient CO_(2) capture and electrocatalytic conversion into C1 products.By adjusting the metal type and replacing the ligand,the mixed metal-based MOF InCo-ABDBC-HIN shows high CO_(2) capture performance(101.7 cm^(3) g^(-1) at 273 K under low pressure)and superior activity(a maximum FEC1 of 81.5% at -2.2 V vs.Ag/Ag^(+))for electrocatalytic CO_(2) reduction in organic electrolytes due to its modified electronic structure.Theoretical calculations suggest that the substitution of In by Co significantly modified the electronic structure of In-based clusters,which provides rich unpaired electrons for the CO_(2)RR and enhances the charge transfer efficiency.This work provides a specially coordinated trinuclear indium cluster-based MOF and sheds new light on the precise structural design of both CO_(2) adsorbents and electrocatalysts for efficient CO_(2) reduction.
基金supported by the National Natural Science Foundation of China(No.21771078,21671074,and 21621001)the 111 Project(B17020)the National Key Research and Development Program of China(2016YFB0701100).
文摘Two novel porous MOFs,[Cu_(2)Cl(TZI)(H_(2)O)_(3)]·4DMA(compound 1)and[Cu_(2)(TZI)(OH)(DMF)]·DMF·H_(2)O(compound 2)(H_(3)TZI=5-(tetrazol-5-yl)isophthalic acid,DMA=N,N-dimethylacetamide,and DMF=N,N-dimethylformamide),have been successfully synthesized using the same ligand consisting of isophthalate and tetrazolate groups and CuCl_(2)·2H_(2)O through the secondary building unit(SBU)strategy.Both compounds are constructed from copper cluster-based SBUs.Compound 1 is made up of two different cages based on a Cu paddlewheel and rare-reported double-crown like hexanuclear Cu cluster.In this SBU,the Cu atom adopts a five-coordination in a trigonal bipyramidal configuration,which is very rare in reported MOFs.Moreover,compound 1 with dual functionalities of open metal sites(OMSs)and N-rich Lewis basic sites(LBSs)exhibits good CO_(2) adsorption(92 cm^(3) g^(-1) at 273 K)and high-effect separation ability(9.6 for CO_(2)/CH_(4)=0.5/0.5 under 1 bar at 298 K).
