Benzimidazoles are very important chemical materials in the pharmaceutical industry,and the most common synthetic route is cyclization of o-phenylenediamine with carbon sources,in which utilization of inexpensive and ...Benzimidazoles are very important chemical materials in the pharmaceutical industry,and the most common synthetic route is cyclization of o-phenylenediamine with carbon sources,in which utilization of inexpensive and abundant CO_(2)as C1 source is very impressive.Porous aromatic frameworks(PAFs)with highly desired skeletons have attracted great attentions in gas capture and catalysis.Herein,B-based PAF-165 and PAF-166 are designed and synthesized via Friedel-Crafts alkylation reaction,which present high surface areas as well as high stability.Benefiting from the abundant electron-deficient B centers,both PAFs exhibit excellent selective CO_(2)adsorption abilities.The presence of sterically hindered B units in PAFs can act as Lewis acid active sites for the frustrated Lewis pairs(FLPs)in situ formation with ophenylenediamine,thus promoting the synthesis of benzimidazole.The optimal reaction conditions for o-phenylenediamine cyclization with PAF catalysts are explored,and the reaction mechanism is also proposed.This work provides feasible ideas for incorporating FLPs within porous materials as reusable heterogeneous catalysts for CO_(2)capture and conversion.展开更多
Cationic azole-based metal-organic frameworks(MOFs)with remarkable stability and unique pore environment have aroused great research interests.Meanwhile,flexible MOFs which can undergo pore-structure changes upon expo...Cationic azole-based metal-organic frameworks(MOFs)with remarkable stability and unique pore environment have aroused great research interests.Meanwhile,flexible MOFs which can undergo pore-structure changes upon exposure to external stimuli are ideal materials for gas separation.However,introducing flexibility into the framework of cationic azole-based MOFs is rarely reported.Herein,we synthesized two stable isomorphic cationic MOFs(M-btz-as,M=Co,Ni)based on a linear azole ligand.After activated at high temperature under vacuum,M-btz-ht(M=Co,Ni)were obtained and both MOFs exhibited flexible features in which Co-btz is more flexible than Ni-btz.Different solvent-mediated activation methods were employed to explore their effects on structural flexibility and produced MOFs with different phases.Continuous phase transformation of Co-btz-e was verified by powder X-ray diffraction.In addition,these MOF phases possessed different gas separation abilities affected by their flexible frameworks,and Co-btz-ht exhibited the highest CO_(2)/CH4 separation ability.展开更多
Covalent organic frameworks(COFs)are prominent porous materials for molecules separation due to their desirable structures.However,very few COFs are reported for the separation of macromolecules such as low molecular-...Covalent organic frameworks(COFs)are prominent porous materials for molecules separation due to their desirable structures.However,very few COFs are reported for the separation of macromolecules such as low molecular-weight(MW)proteins.Here,two stable mesoporous COFs(Azo-COF and Tp-COF)with highly crystallized frameworks are synthesized,and their pore sizes are slightly-regulated via elaborate selection of pyrene knots and amino linkages.Benefiting from the pore size difference less than 4 ?,the tandem utilization of these two COFs exhibits efficiently size-selective separation ability towards low MW proteins cytochrome c and myoglobin with small MW difference of 2 kDa,in which protein adsorption possibilities are verified by computational calculations together with confocal laser scanning microscopy(CLSM).Furthermore,a simple COF-based separation device is designed and prepared to achieve effective and low-consumption proteins separation.This work has offered an optimized synthetic strategy for fine-tuned mesoporous COFs and expanded their applications on macromolecules separation.展开更多
基金the financial support by the Fundamental Research Funds for the Central Universities(No.2412019FZ008)the National Natural Science Foundation of China(Nos.22131004 and U21A20330)the"111 Project(No.B18012)。
文摘Benzimidazoles are very important chemical materials in the pharmaceutical industry,and the most common synthetic route is cyclization of o-phenylenediamine with carbon sources,in which utilization of inexpensive and abundant CO_(2)as C1 source is very impressive.Porous aromatic frameworks(PAFs)with highly desired skeletons have attracted great attentions in gas capture and catalysis.Herein,B-based PAF-165 and PAF-166 are designed and synthesized via Friedel-Crafts alkylation reaction,which present high surface areas as well as high stability.Benefiting from the abundant electron-deficient B centers,both PAFs exhibit excellent selective CO_(2)adsorption abilities.The presence of sterically hindered B units in PAFs can act as Lewis acid active sites for the frustrated Lewis pairs(FLPs)in situ formation with ophenylenediamine,thus promoting the synthesis of benzimidazole.The optimal reaction conditions for o-phenylenediamine cyclization with PAF catalysts are explored,and the reaction mechanism is also proposed.This work provides feasible ideas for incorporating FLPs within porous materials as reusable heterogeneous catalysts for CO_(2)capture and conversion.
基金supports from the Fundamental Research Funds for the Central Universities(No.2412019FZ008)the National Natural Science Foundation of China(Nos.21871105,21503038 and 21531003)the“111”project(No.B18012).
文摘Cationic azole-based metal-organic frameworks(MOFs)with remarkable stability and unique pore environment have aroused great research interests.Meanwhile,flexible MOFs which can undergo pore-structure changes upon exposure to external stimuli are ideal materials for gas separation.However,introducing flexibility into the framework of cationic azole-based MOFs is rarely reported.Herein,we synthesized two stable isomorphic cationic MOFs(M-btz-as,M=Co,Ni)based on a linear azole ligand.After activated at high temperature under vacuum,M-btz-ht(M=Co,Ni)were obtained and both MOFs exhibited flexible features in which Co-btz is more flexible than Ni-btz.Different solvent-mediated activation methods were employed to explore their effects on structural flexibility and produced MOFs with different phases.Continuous phase transformation of Co-btz-e was verified by powder X-ray diffraction.In addition,these MOF phases possessed different gas separation abilities affected by their flexible frameworks,and Co-btz-ht exhibited the highest CO_(2)/CH4 separation ability.
基金The authors are grateful for the financial support from the Fundamental Research Funds for the Central Universities(No.2412019FZ008)the National Natural Science Foundation of China(Nos.21503038 and 22074014)the“111”project(No.B18012).
文摘Covalent organic frameworks(COFs)are prominent porous materials for molecules separation due to their desirable structures.However,very few COFs are reported for the separation of macromolecules such as low molecular-weight(MW)proteins.Here,two stable mesoporous COFs(Azo-COF and Tp-COF)with highly crystallized frameworks are synthesized,and their pore sizes are slightly-regulated via elaborate selection of pyrene knots and amino linkages.Benefiting from the pore size difference less than 4 ?,the tandem utilization of these two COFs exhibits efficiently size-selective separation ability towards low MW proteins cytochrome c and myoglobin with small MW difference of 2 kDa,in which protein adsorption possibilities are verified by computational calculations together with confocal laser scanning microscopy(CLSM).Furthermore,a simple COF-based separation device is designed and prepared to achieve effective and low-consumption proteins separation.This work has offered an optimized synthetic strategy for fine-tuned mesoporous COFs and expanded their applications on macromolecules separation.
