Two new 3D,Zn(Ⅱ)–organic frameworks,[{Zn(BINDI)_(0.5)(bpa)_(0.5)(H_(2)O)}·4H_(2)O]_(n)(MOF1)and[{Zn(BINDI)_(0.5)(bpe)}·3H_(2)O]_(n)(MOF2)(where H_(4)BINDI=N,N’-bis(5-isophthalic acid)naphthalenediimide,bp...Two new 3D,Zn(Ⅱ)–organic frameworks,[{Zn(BINDI)_(0.5)(bpa)_(0.5)(H_(2)O)}·4H_(2)O]_(n)(MOF1)and[{Zn(BINDI)_(0.5)(bpe)}·3H_(2)O]_(n)(MOF2)(where H_(4)BINDI=N,N’-bis(5-isophthalic acid)naphthalenediimide,bpa=1,2-bis(4-pyridyl)ethane and bpe=1,2-bis(4-pyridyl)ethylene),have been successfully synthesized by room temperature self-assembly and structurally characterized.Both MOF1 and 2 show 2-fold interpenetrated 3D framework structures with 1D channels of dimensions 4.4×9.5 and 4.6×2.5Å^(2) respectively.Gas adsorption studies of the MOFs revealed selective and higher CO_(2) uptake properties of MOF1 over 2 owing to the presence of a polar pore surface and an optimum pore size of 1 for CO_(2) gas molecules.Furthermore,the high water stability and luminescence properties of MOF1 and 2 were exploited for sensing of nitroaromatic pollutants in water.Consequently,both the MOFs exhibit highly selective aqueous-phase sensing of 2,4,6-trinitrophenol(TNP)through a luminescence quenching mechanism.Furthermore,MOF1 exhibits a relatively higher efficiency of TNP detection(LOD=0.6 ppm,K_(sv)=4.9×10^(4) M^(−1))compared to 2(LOD=1.5 ppm,K_(sv)=1.29×10^(4) M^(−1))due to higher resonance energy transfer between MOF1 and TNP owing to their better spectral overlap.Herein,the influence of N,N’-donor spacers on the structure,selective gas adsorption and the sensing properties of two new Zn(Ⅱ)MOFs has been demonstrated.展开更多
In this study,the rational construction of Fe^(Ⅲ)-centered porphyrin-based bifunctional ionic porous organic polymers(Fe-IPOP1/2)for a one-step,halogen-free,cascade transformation of olefins and CO_(2) to cyclic carb...In this study,the rational construction of Fe^(Ⅲ)-centered porphyrin-based bifunctional ionic porous organic polymers(Fe-IPOP1/2)for a one-step,halogen-free,cascade transformation of olefins and CO_(2) to cyclic carbonates as compared to the conventional two-step process involving epoxides is presented.The ionic polymers,Fe-IPOP1/2 showed selective and recyclable uptake of CO_(2) with an interaction energy of 32.2/39.6 kJ mol^(-1) signifying the stronger interaction of carbon dioxide with the frameworks.Both the polymers were found to be thermally stable up to 300℃ and exhibited promising catalytic performance in the one-step,halogen-free synthesis of cyclic carbonates under eco-friendly,cocatalyst/solvent-free,atmospheric pressure conditions.The excellent catalytic activity of Fe-IPOP1/2 for a one-pot synthesis of cyclic carbonates has been ascribed to the presence of highly exposed oxophilic Fe^(Ⅲ) sites and nucleophilic Br-anions in the polymers.Notably,this one-pot synthesis strategy was extended for the transformation of various substituted olefins to their respective carbonates in good yield and selectivity.Further,Fe-IPOP1 showed good reusability with retention of catalytic activity for multiple cycles of usage.展开更多
Selective carbon capture and utilization(CCU)as a C1 feedstock for the synthesis of value-added chemicals under ambient conditions catalyzed by porous MOFs constitutes one of the most promising solutions to mitigate t...Selective carbon capture and utilization(CCU)as a C1 feedstock for the synthesis of value-added chemicals under ambient conditions catalyzed by porous MOFs constitutes one of the most promising solutions to mitigate the growing CO_(2) concentration in the atmosphere.Consequently,the synthesis of a novel 3D,microporous,bifunctional Zn_((II))-organic framework,{[Zn_(2)(TDC)_(2)(DATRZ)]·(3H_(2)O)·(DMF)}n(Zn-DAT)(where TDC=2,5-thiophene dicarboxylate ion and DATRZ=3,5-diamino-1,2,4-triazole),was achieved using a mixed ligand strategy.Single crystal X-ray structural analysis of the MOF revealed the presence of a 3D microporous structure with two types of 1D channels of dimensions 12.5×8.7Å2 and 7.0×4.8Å2 along the crystallographic c-and b-axes,respectively.The presence of basic-NH_(2) functionalized pores in Zn-DAT induces a selective adsorption property of CO_(2) with a high heat of adsorption(Qst)value of 39.5 kJ mol^(-1) which is supported by a theoretically computed binding energy(BE)of 40.9 kJ mol^(-1).Interestingly,the Qst value observed for Zn-DAT is about 8 kJ mol^(-1) higher than that of the analogous MOF{[Zn_(2)(TDC)(TRZ)_(2)]·(DMA)·(MeOH)}n(Zn-TAZ)containing the 1,2,4-triazole(TAZ)linker,which highlights the critical role of-NH_(2) groups in enhancing the interaction energy for CO_(2).The significantly high value of Qst can be attributed to the stronger interaction of the acidic CO_(2) molecule with the basic-NH_(2) groups present in the 1D channels of the Zn-DAT MOF.Furthermore,the presence of both Lewis acidic Zn_(2)+ions and basic-NH_(2) groups resulted in the Zn-DAT MOF as an efficient heterogeneous catalyst for chemical fixation of CO_(2) into cyclic carbonates under mild conditions at RT.Herein,we report a rare example of porous MOFs for the capture and utilization of CO_(2) at RT and the influence of basic-NH_(2) groups on the high value of Qst and catalytic conversion of carbon dioxide.展开更多
The chemical fixation of carbon dioxide into valuable products constitutes a promising step toward reducing the atmospheric CO_(2) concentration.Consequently,herein we report the strategic design of a bifunctional cat...The chemical fixation of carbon dioxide into valuable products constitutes a promising step toward reducing the atmospheric CO_(2) concentration.Consequently,herein we report the strategic design of a bifunctional catalyst by grafting catalytically active Ag(I)ions onto N-heterocyclic carbene(NHC)sites in a MOF for efficient chemical fixation of CO_(2) from a dilute gas to oxazolidinones,bio-relevant commodity chemicals.Indeed,Ag(I)@MOF-NHC demonstrated excellent catalytic activity for efficient fixation of CO_(2) from a dilute gas(CO_(2):N_(2)=13:87%)with alkynes to afford valuable chemicals,oxazolidinones,under RT and atmospheric pressure(balloon)conditions.The superior activity of the Ag(I)anchored MOF over the individual(AgNO_(3) and MOF-NHC)components has been ascribed to the synergistic effect between the CO_(2)-philic NHC and alkynophilic Ag(I)sites exposed in the 1D channels of the MOF.Furthermore,the Ag(I)anchored MOF showed high recyclability without significant loss of catalytic activity and structural rigidity.Overall,this is a unique demonstration of the utilization of dilute CO_(2) under environmentally friendly mild conditions and can pave the way for the development of efficient catalytic systems for sustainable utilization of CO_(2) from dilute gases.展开更多
Excessive reliance on fossil fuels has increased atmospheric CO_(2) emissions,resulting in the greenhouse effect that endangers global climate stability and human well-being.Consequently,the storage and chemical conve...Excessive reliance on fossil fuels has increased atmospheric CO_(2) emissions,resulting in the greenhouse effect that endangers global climate stability and human well-being.Consequently,the storage and chemical conversion of CO_(2) into sustainable products can play a vital role in reducing anthropogenic emissions.Hence,there is an upsurge in research on selective carbon capture,sequestration and utilization(CCSU)to mitigate the rising atmospheric CO_(2) concentration.Carbon capture and utilization(CCU),in particular,has attracted considerable interest because it enables the utilization of CO_(2) as a C1 feedstock for generating commodity chemicals and fuels such as cyclic or polycarbonates,cyclic carbamates,oxazolidinones,formamides,methane,methanol and so on.Among these products,oxazolidinones are essential five-membered heterocyclic compounds found in several important pharmaceuticals.Oxazolidinones also function as versatile intermediates and chiral agents in organic synthesis.Thus,developing highly efficient heterogeneous catalysts containing dense basic and catalytic sites is potentially significant for effectively capturing and transforming CO_(2) into 2-oxazolidinones under ambient conditions.In this regard,porous framework-based materials viz metal-organic frameworks(MOFs),covalent organic frameworks(COFs)and porous organic polymers(POPs)are excellent candidates owing to their fascinating attributes,like ample active sites,intrinsic porosity and accessible functionalities.These frameworkbased materials have been exploited as recyclable catalysts in efficient cyclization of CO_(2) with aziridines,propargylic amines and alcohols coupled with amines/epoxides to produce oxazolidinones.This review provides a detailed analysis of recent advancements in developing porous framework-based recyclable catalysts for environmentally friendly conversion of CO_(2) to oxazolidinones.Furthermore,future considerations and challenges for fabricating efficient framework-based catalysts in transforming CO_(2) into valueadded oxazolidinones are also discussed.展开更多
Two new homochiral metal-organic frameworks of Cd(II),[{Cd_(2)(L-glu)2(bpe)3(H_(2)O)}·2H_(2)O](1)and[{Cd_(3)(L-glu)2(bpe)3(H_(2)O)}·2NO_(3)·H_(2)O](2)(where,L-glu=L-glutamate dianion,and bpe=1,2-bis(4-p...Two new homochiral metal-organic frameworks of Cd(II),[{Cd_(2)(L-glu)2(bpe)3(H_(2)O)}·2H_(2)O](1)and[{Cd_(3)(L-glu)2(bpe)3(H_(2)O)}·2NO_(3)·H_(2)O](2)(where,L-glu=L-glutamate dianion,and bpe=1,2-bis(4-pyridyl)ethylene)have been synthesized solvothermally by employing two different temperatures.Single crystal X-ray diffraction studies revealed that both 1 and 2 are homochiral and possess a 3D pillar-layered framework structure having 4,8-and 8,10-connected binodal nets with vertex symbols of{3^2.4.5^3}{3^4.4^6.5^10.6^8}and{3^11.4^28.5^5.6}2{3^8.4^18.5.6},respectively.Interestingly,solvothermal synthesis carried out at 100°C resulted in a 3D framework,1 which features large rectangular 1D channels with a dimension of∼10.38×4.44Å2 decorated with pendant-NH_(2)groups.Whereas,increasing the temperature of the reaction to 120℃ led to a non-porous highly connected 3D framework,2 in which the-NH_(2)group of the L-glu ligand is coordinated to a Cd(II)node.Gas(N_(2),CO_(2),H_(2)and Ar)uptake studies on the dehydrated framework of 1 revealed excellent selectivity for CO_(2)over other gases at 273 K with a high isosteric heat of adsorption(Qst)value of 40.8 kJmol^(−1).The high selectivity for CO_(2)gas has been attributed to the stronger interaction of CO_(2)with the basic-NH_(2)functionalized pore surface of compound 1.Furthermore,1 acts as a very good recyclable catalyst for the carbon-carbon bond forming reactions,such as the Knoevenagel condensation and Henry reaction of benzaldehydes.Moreover,the catalyst can be easily separated from the reaction mixture and reused in four consecutive cycles without significant loss of catalytic activity and structural rigidity.展开更多
文摘Two new 3D,Zn(Ⅱ)–organic frameworks,[{Zn(BINDI)_(0.5)(bpa)_(0.5)(H_(2)O)}·4H_(2)O]_(n)(MOF1)and[{Zn(BINDI)_(0.5)(bpe)}·3H_(2)O]_(n)(MOF2)(where H_(4)BINDI=N,N’-bis(5-isophthalic acid)naphthalenediimide,bpa=1,2-bis(4-pyridyl)ethane and bpe=1,2-bis(4-pyridyl)ethylene),have been successfully synthesized by room temperature self-assembly and structurally characterized.Both MOF1 and 2 show 2-fold interpenetrated 3D framework structures with 1D channels of dimensions 4.4×9.5 and 4.6×2.5Å^(2) respectively.Gas adsorption studies of the MOFs revealed selective and higher CO_(2) uptake properties of MOF1 over 2 owing to the presence of a polar pore surface and an optimum pore size of 1 for CO_(2) gas molecules.Furthermore,the high water stability and luminescence properties of MOF1 and 2 were exploited for sensing of nitroaromatic pollutants in water.Consequently,both the MOFs exhibit highly selective aqueous-phase sensing of 2,4,6-trinitrophenol(TNP)through a luminescence quenching mechanism.Furthermore,MOF1 exhibits a relatively higher efficiency of TNP detection(LOD=0.6 ppm,K_(sv)=4.9×10^(4) M^(−1))compared to 2(LOD=1.5 ppm,K_(sv)=1.29×10^(4) M^(−1))due to higher resonance energy transfer between MOF1 and TNP owing to their better spectral overlap.Herein,the influence of N,N’-donor spacers on the structure,selective gas adsorption and the sensing properties of two new Zn(Ⅱ)MOFs has been demonstrated.
基金the Science&Engineering Research Board(SERB),Department of Science and Technology,Govt.of India,for financial support(CRG/2018/001176).
文摘In this study,the rational construction of Fe^(Ⅲ)-centered porphyrin-based bifunctional ionic porous organic polymers(Fe-IPOP1/2)for a one-step,halogen-free,cascade transformation of olefins and CO_(2) to cyclic carbonates as compared to the conventional two-step process involving epoxides is presented.The ionic polymers,Fe-IPOP1/2 showed selective and recyclable uptake of CO_(2) with an interaction energy of 32.2/39.6 kJ mol^(-1) signifying the stronger interaction of carbon dioxide with the frameworks.Both the polymers were found to be thermally stable up to 300℃ and exhibited promising catalytic performance in the one-step,halogen-free synthesis of cyclic carbonates under eco-friendly,cocatalyst/solvent-free,atmospheric pressure conditions.The excellent catalytic activity of Fe-IPOP1/2 for a one-pot synthesis of cyclic carbonates has been ascribed to the presence of highly exposed oxophilic Fe^(Ⅲ) sites and nucleophilic Br-anions in the polymers.Notably,this one-pot synthesis strategy was extended for the transformation of various substituted olefins to their respective carbonates in good yield and selectivity.Further,Fe-IPOP1 showed good reusability with retention of catalytic activity for multiple cycles of usage.
基金the Science&Engineering Research Board(SERB),Department of Science and Technology,Government of India for financial support(CRG/2018/001176).
文摘Selective carbon capture and utilization(CCU)as a C1 feedstock for the synthesis of value-added chemicals under ambient conditions catalyzed by porous MOFs constitutes one of the most promising solutions to mitigate the growing CO_(2) concentration in the atmosphere.Consequently,the synthesis of a novel 3D,microporous,bifunctional Zn_((II))-organic framework,{[Zn_(2)(TDC)_(2)(DATRZ)]·(3H_(2)O)·(DMF)}n(Zn-DAT)(where TDC=2,5-thiophene dicarboxylate ion and DATRZ=3,5-diamino-1,2,4-triazole),was achieved using a mixed ligand strategy.Single crystal X-ray structural analysis of the MOF revealed the presence of a 3D microporous structure with two types of 1D channels of dimensions 12.5×8.7Å2 and 7.0×4.8Å2 along the crystallographic c-and b-axes,respectively.The presence of basic-NH_(2) functionalized pores in Zn-DAT induces a selective adsorption property of CO_(2) with a high heat of adsorption(Qst)value of 39.5 kJ mol^(-1) which is supported by a theoretically computed binding energy(BE)of 40.9 kJ mol^(-1).Interestingly,the Qst value observed for Zn-DAT is about 8 kJ mol^(-1) higher than that of the analogous MOF{[Zn_(2)(TDC)(TRZ)_(2)]·(DMA)·(MeOH)}n(Zn-TAZ)containing the 1,2,4-triazole(TAZ)linker,which highlights the critical role of-NH_(2) groups in enhancing the interaction energy for CO_(2).The significantly high value of Qst can be attributed to the stronger interaction of the acidic CO_(2) molecule with the basic-NH_(2) groups present in the 1D channels of the Zn-DAT MOF.Furthermore,the presence of both Lewis acidic Zn_(2)+ions and basic-NH_(2) groups resulted in the Zn-DAT MOF as an efficient heterogeneous catalyst for chemical fixation of CO_(2) into cyclic carbonates under mild conditions at RT.Herein,we report a rare example of porous MOFs for the capture and utilization of CO_(2) at RT and the influence of basic-NH_(2) groups on the high value of Qst and catalytic conversion of carbon dioxide.
基金DST-SERB for the financial support(grant no.CRG/2018/001176)。
文摘The chemical fixation of carbon dioxide into valuable products constitutes a promising step toward reducing the atmospheric CO_(2) concentration.Consequently,herein we report the strategic design of a bifunctional catalyst by grafting catalytically active Ag(I)ions onto N-heterocyclic carbene(NHC)sites in a MOF for efficient chemical fixation of CO_(2) from a dilute gas to oxazolidinones,bio-relevant commodity chemicals.Indeed,Ag(I)@MOF-NHC demonstrated excellent catalytic activity for efficient fixation of CO_(2) from a dilute gas(CO_(2):N_(2)=13:87%)with alkynes to afford valuable chemicals,oxazolidinones,under RT and atmospheric pressure(balloon)conditions.The superior activity of the Ag(I)anchored MOF over the individual(AgNO_(3) and MOF-NHC)components has been ascribed to the synergistic effect between the CO_(2)-philic NHC and alkynophilic Ag(I)sites exposed in the 1D channels of the MOF.Furthermore,the Ag(I)anchored MOF showed high recyclability without significant loss of catalytic activity and structural rigidity.Overall,this is a unique demonstration of the utilization of dilute CO_(2) under environmentally friendly mild conditions and can pave the way for the development of efficient catalytic systems for sustainable utilization of CO_(2) from dilute gases.
基金C.M.N.acknowledges DST-SERB(CRG/2018/001176)for financial supportPR thanks DST-SERB(PDF/2023/000057)for funding in the form of NPDF.
文摘Excessive reliance on fossil fuels has increased atmospheric CO_(2) emissions,resulting in the greenhouse effect that endangers global climate stability and human well-being.Consequently,the storage and chemical conversion of CO_(2) into sustainable products can play a vital role in reducing anthropogenic emissions.Hence,there is an upsurge in research on selective carbon capture,sequestration and utilization(CCSU)to mitigate the rising atmospheric CO_(2) concentration.Carbon capture and utilization(CCU),in particular,has attracted considerable interest because it enables the utilization of CO_(2) as a C1 feedstock for generating commodity chemicals and fuels such as cyclic or polycarbonates,cyclic carbamates,oxazolidinones,formamides,methane,methanol and so on.Among these products,oxazolidinones are essential five-membered heterocyclic compounds found in several important pharmaceuticals.Oxazolidinones also function as versatile intermediates and chiral agents in organic synthesis.Thus,developing highly efficient heterogeneous catalysts containing dense basic and catalytic sites is potentially significant for effectively capturing and transforming CO_(2) into 2-oxazolidinones under ambient conditions.In this regard,porous framework-based materials viz metal-organic frameworks(MOFs),covalent organic frameworks(COFs)and porous organic polymers(POPs)are excellent candidates owing to their fascinating attributes,like ample active sites,intrinsic porosity and accessible functionalities.These frameworkbased materials have been exploited as recyclable catalysts in efficient cyclization of CO_(2) with aziridines,propargylic amines and alcohols coupled with amines/epoxides to produce oxazolidinones.This review provides a detailed analysis of recent advancements in developing porous framework-based recyclable catalysts for environmentally friendly conversion of CO_(2) to oxazolidinones.Furthermore,future considerations and challenges for fabricating efficient framework-based catalysts in transforming CO_(2) into valueadded oxazolidinones are also discussed.
基金financial support from the Department of Science and Technology(DST)Fast Track Proposal(SR/FT/CS-112/2011).
文摘Two new homochiral metal-organic frameworks of Cd(II),[{Cd_(2)(L-glu)2(bpe)3(H_(2)O)}·2H_(2)O](1)and[{Cd_(3)(L-glu)2(bpe)3(H_(2)O)}·2NO_(3)·H_(2)O](2)(where,L-glu=L-glutamate dianion,and bpe=1,2-bis(4-pyridyl)ethylene)have been synthesized solvothermally by employing two different temperatures.Single crystal X-ray diffraction studies revealed that both 1 and 2 are homochiral and possess a 3D pillar-layered framework structure having 4,8-and 8,10-connected binodal nets with vertex symbols of{3^2.4.5^3}{3^4.4^6.5^10.6^8}and{3^11.4^28.5^5.6}2{3^8.4^18.5.6},respectively.Interestingly,solvothermal synthesis carried out at 100°C resulted in a 3D framework,1 which features large rectangular 1D channels with a dimension of∼10.38×4.44Å2 decorated with pendant-NH_(2)groups.Whereas,increasing the temperature of the reaction to 120℃ led to a non-porous highly connected 3D framework,2 in which the-NH_(2)group of the L-glu ligand is coordinated to a Cd(II)node.Gas(N_(2),CO_(2),H_(2)and Ar)uptake studies on the dehydrated framework of 1 revealed excellent selectivity for CO_(2)over other gases at 273 K with a high isosteric heat of adsorption(Qst)value of 40.8 kJmol^(−1).The high selectivity for CO_(2)gas has been attributed to the stronger interaction of CO_(2)with the basic-NH_(2)functionalized pore surface of compound 1.Furthermore,1 acts as a very good recyclable catalyst for the carbon-carbon bond forming reactions,such as the Knoevenagel condensation and Henry reaction of benzaldehydes.Moreover,the catalyst can be easily separated from the reaction mixture and reused in four consecutive cycles without significant loss of catalytic activity and structural rigidity.
