The novel Metal-Organic Frameworks(MOFs)M(BPZNH_(2))(M=Zn,Ni,Cu)were prepared from the reaction of the corresponding metal acetates M(OAc)_(2)·nH_(2)O and the organic linker 3-amino-4,4’-bipyrazole(H_(2)BPZNH_(2...The novel Metal-Organic Frameworks(MOFs)M(BPZNH_(2))(M=Zn,Ni,Cu)were prepared from the reaction of the corresponding metal acetates M(OAc)_(2)·nH_(2)O and the organic linker 3-amino-4,4’-bipyrazole(H_(2)BPZNH_(2))under solvothermal conditions.H_(2)BPZNH_(2) was obtained straightforwardly from the reduction of the related nitro-compound using hydrazine as a reducing agent.The Zn(II)polymer is characterized by a 3D porous network featuring tetrahedral metallic nodes and bridging BPZNH_(2)^(2-)anions defining the vertices and edges of square channels.The isostructural Ni(II)and Cu(II)MOFs show square-planar metallic nodes and bridging BPZNH_(2)^(2-)spacers at the vertices and edges of the rhombic channels of a 3D porous framework.All the MOFs were characterized in the solid state[(VT)-PXRD,IR,TGA-DTG].The textural property analysis revealed that they are micro-mesoporous materials with BET specific surface areas(SSAs)falling in the 100-400 m^(2) g^(-1) range.Zn(BPZNH_(2)),showing the highest SSA(395 m^(2) g^(-1))and a prevalently microporous texture(micropore area=69%of the accessible SSA),has been exploited as a CO_(2) capture material:at T=298 K and pCO_(2)=1 bar,the total gas uptake equals 3.07 mmol g^(-1)(13.5 wt%CO_(2)).Its affinity for CO_(2)(isosteric heat of adsorption Qst=35.6 kJ mol^(-1);CO_(2)/N_(2) Henry selectivity=17;CO_(2)/N_(2) IAST selectivity=14)is higher than that of its nitrofunctionalized analogue and comparable to that of other amino-decorated MOFs from the literature.Finally,Zn(BPZNH_(2))was tested as a heterogeneous catalyst in the reaction of CO_(2) with activated epoxides bearing a-CH_(2)X pendant arm(X=Cl:epichlorohydrin;X=Br:epibromohydrin)to give the corresponding cyclic carbonates at T=393 K and pCO_(2)=1 bar under green(solvent-and co-catalyst-free)conditions.A good conversion of 47%and a TOF of 3.9 mmol(carbonate)(mmolZn)^(-1) h^(-1) were recorded with epibromohydrin.展开更多
Solvent-assisted ligand exchange in the zirconium metal–organic framework(MOF)UiO-67[Zr_(6)O_(4)(OH)_(4)(PhPh)_(6);H_(2)PhPh=biphenyl-4,4’-dicarboxylic acid]with the heterocyclic linkers H_(2)TpTp(2,2’-bithiophene-...Solvent-assisted ligand exchange in the zirconium metal–organic framework(MOF)UiO-67[Zr_(6)O_(4)(OH)_(4)(PhPh)_(6);H_(2)PhPh=biphenyl-4,4’-dicarboxylic acid]with the heterocyclic linkers H_(2)TpTp(2,2’-bithiophene-5,5’-dicarboxylic acid)and H_(2)TzTz(2,2’-bithiazole-5,5’-dicarboxylic acid)in an equimolar[Zr_(6)]:linker ratio led to the corresponding MIXMOFs UiO-67-TpTp[Zr_(6)O_(4)(OH)_(4)(PhPh)_(5)(TpTp)]and UiO-67-TzTz[Zr_(6)O_(4)(OH)_(4)(PhPh)_(5)(TzTz)].Both MOFs have been thoroughly characterized in the solid state.They show the same structural topology and crystal structure of UiO-67,as confirmed by powder X-ray diffraction.Their BET specific surface area is lower than that of their parent material(1700 and 1310 m^(2) g^(−1) for UiO-67-TpTp and UiO-67-TzTz,respectively,vs.1877 m^(2) g^(−1) for UiO-67),while the thermal stability of UiO-67(T_(dec)=819 K)is maintained.The“diluted”inclusion,in the UiO-673D framework,of luminescent heterocyclic linkers emitting in the blue-green visible region induces luminescence in the final MOFs(emission λ_(max)=442 and 420 nm for UiO-67-TpTp and UiO-67-TzTz,respectively),preventing self-quenching effects caused by the proximity of the emitters in the crystal structure.Both MOFs have been tested as sensors for contaminants of emerging concern(CECs)in water:an emission intensity increase has been observed when suspended in contact with diclofenac sodium,fluoxetine,ibuprofen and sulfamethoxazole.In particular,UiO-67-TzTz has shown a linearly increasing trend for a specific concentration range(up to 30–40μM for diclofenac,fluoxetine and ibuprofen;up to 100μM for sulfamethoxazole).UiO-67-TzTz also behaves as an adsorbent vs.diclofenac,with a maximum adsorption capacity(Xm)of 62.5 mg g^(−1).These findings pave the way to the practical utilization of UiO-67-TzTz as a multifunctional material(i.e.CECs luminescent sensor and adsorbent at one time)for environmental remediation.展开更多
基金the University of Camerino and the Italian MIUR throughout the PRIN 2015 Project Towards a Sustainable Chemistry(20154X9ATP_002).
文摘The novel Metal-Organic Frameworks(MOFs)M(BPZNH_(2))(M=Zn,Ni,Cu)were prepared from the reaction of the corresponding metal acetates M(OAc)_(2)·nH_(2)O and the organic linker 3-amino-4,4’-bipyrazole(H_(2)BPZNH_(2))under solvothermal conditions.H_(2)BPZNH_(2) was obtained straightforwardly from the reduction of the related nitro-compound using hydrazine as a reducing agent.The Zn(II)polymer is characterized by a 3D porous network featuring tetrahedral metallic nodes and bridging BPZNH_(2)^(2-)anions defining the vertices and edges of square channels.The isostructural Ni(II)and Cu(II)MOFs show square-planar metallic nodes and bridging BPZNH_(2)^(2-)spacers at the vertices and edges of the rhombic channels of a 3D porous framework.All the MOFs were characterized in the solid state[(VT)-PXRD,IR,TGA-DTG].The textural property analysis revealed that they are micro-mesoporous materials with BET specific surface areas(SSAs)falling in the 100-400 m^(2) g^(-1) range.Zn(BPZNH_(2)),showing the highest SSA(395 m^(2) g^(-1))and a prevalently microporous texture(micropore area=69%of the accessible SSA),has been exploited as a CO_(2) capture material:at T=298 K and pCO_(2)=1 bar,the total gas uptake equals 3.07 mmol g^(-1)(13.5 wt%CO_(2)).Its affinity for CO_(2)(isosteric heat of adsorption Qst=35.6 kJ mol^(-1);CO_(2)/N_(2) Henry selectivity=17;CO_(2)/N_(2) IAST selectivity=14)is higher than that of its nitrofunctionalized analogue and comparable to that of other amino-decorated MOFs from the literature.Finally,Zn(BPZNH_(2))was tested as a heterogeneous catalyst in the reaction of CO_(2) with activated epoxides bearing a-CH_(2)X pendant arm(X=Cl:epichlorohydrin;X=Br:epibromohydrin)to give the corresponding cyclic carbonates at T=393 K and pCO_(2)=1 bar under green(solvent-and co-catalyst-free)conditions.A good conversion of 47%and a TOF of 3.9 mmol(carbonate)(mmolZn)^(-1) h^(-1) were recorded with epibromohydrin.
基金the PRIN 2017 project MULTI-e(Ref.20179337R7)“Multielectron transfer for the conversion of small molecules:an enabling technology for the chemical use of renewable energy”the TRAINER project“Catalysts for Transition to Renewable Energy Future”(Ref.ANR-17-MPGA-0017)for financial support.C.P.thanks Fondazione con il Sud for funding the project HApECOrk(Ref.2015-0243).
文摘Solvent-assisted ligand exchange in the zirconium metal–organic framework(MOF)UiO-67[Zr_(6)O_(4)(OH)_(4)(PhPh)_(6);H_(2)PhPh=biphenyl-4,4’-dicarboxylic acid]with the heterocyclic linkers H_(2)TpTp(2,2’-bithiophene-5,5’-dicarboxylic acid)and H_(2)TzTz(2,2’-bithiazole-5,5’-dicarboxylic acid)in an equimolar[Zr_(6)]:linker ratio led to the corresponding MIXMOFs UiO-67-TpTp[Zr_(6)O_(4)(OH)_(4)(PhPh)_(5)(TpTp)]and UiO-67-TzTz[Zr_(6)O_(4)(OH)_(4)(PhPh)_(5)(TzTz)].Both MOFs have been thoroughly characterized in the solid state.They show the same structural topology and crystal structure of UiO-67,as confirmed by powder X-ray diffraction.Their BET specific surface area is lower than that of their parent material(1700 and 1310 m^(2) g^(−1) for UiO-67-TpTp and UiO-67-TzTz,respectively,vs.1877 m^(2) g^(−1) for UiO-67),while the thermal stability of UiO-67(T_(dec)=819 K)is maintained.The“diluted”inclusion,in the UiO-673D framework,of luminescent heterocyclic linkers emitting in the blue-green visible region induces luminescence in the final MOFs(emission λ_(max)=442 and 420 nm for UiO-67-TpTp and UiO-67-TzTz,respectively),preventing self-quenching effects caused by the proximity of the emitters in the crystal structure.Both MOFs have been tested as sensors for contaminants of emerging concern(CECs)in water:an emission intensity increase has been observed when suspended in contact with diclofenac sodium,fluoxetine,ibuprofen and sulfamethoxazole.In particular,UiO-67-TzTz has shown a linearly increasing trend for a specific concentration range(up to 30–40μM for diclofenac,fluoxetine and ibuprofen;up to 100μM for sulfamethoxazole).UiO-67-TzTz also behaves as an adsorbent vs.diclofenac,with a maximum adsorption capacity(Xm)of 62.5 mg g^(−1).These findings pave the way to the practical utilization of UiO-67-TzTz as a multifunctional material(i.e.CECs luminescent sensor and adsorbent at one time)for environmental remediation.
