In this work grand canonical Monte Carlo simulations were performed to study gas separation in three pairs of isoreticular metal-organic frameworks (IRMOFs) with and without catenation at room temperature.Mixture comp...In this work grand canonical Monte Carlo simulations were performed to study gas separation in three pairs of isoreticular metal-organic frameworks (IRMOFs) with and without catenation at room temperature.Mixture composed of CO2 and H2 was selected as the model system to separate.The results show that CO2 selectivity in catenated MOFs with multi-porous frameworks is much higher than their non-catenated counterparts.The simulations also show that the electrostatic interactions are very important for the selectivity,and the contributions of different electrostatic interactions are different,depending on pore size,pressure and mixture composition.In fact,changing the electrostatic interactions can even qualitatively change the adsorption behavior.A general conclusion is that the electrostatic interactions between adsorbate molecules and the framework atoms play a dominant role at low pressures,and these interactions in catenated MOFs have much more pronounced effects than those in their non-catenated counterparts,while the electrostatic interactions between adsorbate molecules become evident with increasing pressure,and eventually dominant.展开更多
In thiswork,the perovskite LaZnO_(3) was synthesized via sol-gel method and applied for photocatalytic treatment of sulfamethizole(SMZ)antibiotics under visible light activation.SMZ was almost completely degraded(99.2...In thiswork,the perovskite LaZnO_(3) was synthesized via sol-gel method and applied for photocatalytic treatment of sulfamethizole(SMZ)antibiotics under visible light activation.SMZ was almost completely degraded(99.2%±0.3%)within 4 hr by photocatalyst LaZnO_(3) at the optimal dosage of 1.1 g/L,with amineralization proportion of 58.7%±0.4%.The efficient performance of LaZnO_(3) can be attributed to itswide-range light absorption and the appropriate energy band edge levels,which facilitate the formation of active agents such as·O_(2)^(−),h^(+),and·OH.The integration of RP-HPLC/Q-TOF-MS and DFT-based computational techniques revealed three degradation pathways of SMZ,which were initiated by the deamination reaction at the aniline ring,the breakdown of the sulfonamidemoieties,and a process known as Smile-type rearrangement and SO2 intrusion.Corresponding toxicity of SMZ and the intermediateswere analyzed by quantitative structure activity relationship(QSAR),indicating the effectiveness of LaZnO_(3)-based photocatalysis in preventing secondary pollution of the intermediates to the ecosystem during the degradation process.The visible-light-activated photocatalyst LaZnO_(3) exhibited efficient performance in the occurrence of inorganic anions and maintained high durability across multiple recycling tests,making it a promising candidate for practical antibiotic treatment.展开更多
Organoboron compounds are highly versatile building blocks in modern organic synthesis,pharmaceuticals,and materials science,offering unique reactivity and stability for the assembly of complex molecular structures.Th...Organoboron compounds are highly versatile building blocks in modern organic synthesis,pharmaceuticals,and materials science,offering unique reactivity and stability for the assembly of complex molecular structures.The hydroboration of allenes stands out as a straightforward method for the preparation of allyl and alkenyl boranes.Nonetheless,achieving precise control over regio-and stereoselectivity in these reactions presents significant challenges.In this review,we have systematically summarized the selective hydroboration of allenes catalyzed by a range of transition metals,including platinum,copper,palladium,cobalt,nickel,and ruthenium catalysts.The significant advancements,current limitations,and future perspective for the transition metal-catalyzed selective hydroboration are also highlighted.Moreover,we hope that this review will help understand more about the catalytic hydroboration of allenes and stimulate the further development of both allene and organoboron chemistry.展开更多
In the intricate process of natural product biosynthesis,a metabolon can enhance metabolic flux by associating sequential enzymes.A fungal metabolon,comprising of flavin-dependent monooxygenase Spe F and P450 monooxyg...In the intricate process of natural product biosynthesis,a metabolon can enhance metabolic flux by associating sequential enzymes.A fungal metabolon,comprising of flavin-dependent monooxygenase Spe F and P450 monooxygenase Spe G,is identified in the biosynthesis of spiro polycyclic alkaloids(+)-notoamide B and its diastereomer(+)-versicolamide B.Using notoamide E as a substance,Spe F/Spe G metabolon can control the stereoselectivity of its 2,3-epoxidation,followed by hydrogen atom ion at C-17 to generate reactive epoxide tau-m A with dienyl iminium unit.Subsequently,(+)-notoamide B and(+)-versicolamide B are produced via tandem nonenzymatic inverse-electron-demand Diels-Alder reaction and semipinacol rearrangement.This provides the first example of metabolon in the biosynthesis of spiro-prenylated indole alkaloids.展开更多
By utilizing the classical turning point of the electron movement, we have defined and computed the mo-lecular intrinsic characteristic contour (MICC) via the com-bination of the ab initio quantum chemistry computatio...By utilizing the classical turning point of the electron movement, we have defined and computed the mo-lecular intrinsic characteristic contour (MICC) via the com-bination of the ab initio quantum chemistry computational method with the ionization potential measured by photo-electron spectroscopy experiment. In this paper, we calcu-lated the MICCs of several small organic molecules contain-ing oxygen atom for the first time. The three-dimensional pictures have been drawn, by performing a large number of calculations. The analysis on some characterized cross-sec-tions of the MICC can provide atomic spatial changing information in the process of forming a molecule.展开更多
The potential acting on an electron within a molecule (PAEM) is formulated, and then calculated using the ab initio MELD program plus a separate calculation program in the RHF molecular orbital theory, finally the thr...The potential acting on an electron within a molecule (PAEM) is formulated, and then calculated using the ab initio MELD program plus a separate calculation program in the RHF molecular orbital theory, finally the three-dimensional graphs of the potentials have been drawn. We have systematically investigated this kind of the potentials for a series of the diatomic molecules, such as HF, HCl, HBr, LiF, LiCl, and so on. The three-dimensional graph can clearly display the variation of the potential felt by an electron within a molecule and get a deeper understanding of the electronic motion and chemical bonding within a molecule.展开更多
Densely functionalized chiral nitrogen-containing heterocycles are ubiquitous in bioactive synthetic compounds and natural products.Herein,we report a nickel(Ni)-catalyzed enantioselective desymmetrizing aza-Heck cycl...Densely functionalized chiral nitrogen-containing heterocycles are ubiquitous in bioactive synthetic compounds and natural products.Herein,we report a nickel(Ni)-catalyzed enantioselective desymmetrizing aza-Heck cyclization of oxime esters with a commercially available chiral pyridinebis(oxazoline)(pybox)ligand.This reaction proceeds under mild reaction conditions,tolerates various functional groups,and leads to chiral 2-substituted-3,7a-dihydro-3aH-indoles.展开更多
基金Supported by the National Natural Science Foundation of China （20725622, 20706002, and 20876006）, Beijing Nova Program （2008B15） and the Dutch STW/CW Separation Technology Program （700.56.655-DPC.6243）.
文摘In this work grand canonical Monte Carlo simulations were performed to study gas separation in three pairs of isoreticular metal-organic frameworks (IRMOFs) with and without catenation at room temperature.Mixture composed of CO2 and H2 was selected as the model system to separate.The results show that CO2 selectivity in catenated MOFs with multi-porous frameworks is much higher than their non-catenated counterparts.The simulations also show that the electrostatic interactions are very important for the selectivity,and the contributions of different electrostatic interactions are different,depending on pore size,pressure and mixture composition.In fact,changing the electrostatic interactions can even qualitatively change the adsorption behavior.A general conclusion is that the electrostatic interactions between adsorbate molecules and the framework atoms play a dominant role at low pressures,and these interactions in catenated MOFs have much more pronounced effects than those in their non-catenated counterparts,while the electrostatic interactions between adsorbate molecules become evident with increasing pressure,and eventually dominant.
文摘In thiswork,the perovskite LaZnO_(3) was synthesized via sol-gel method and applied for photocatalytic treatment of sulfamethizole(SMZ)antibiotics under visible light activation.SMZ was almost completely degraded(99.2%±0.3%)within 4 hr by photocatalyst LaZnO_(3) at the optimal dosage of 1.1 g/L,with amineralization proportion of 58.7%±0.4%.The efficient performance of LaZnO_(3) can be attributed to itswide-range light absorption and the appropriate energy band edge levels,which facilitate the formation of active agents such as·O_(2)^(−),h^(+),and·OH.The integration of RP-HPLC/Q-TOF-MS and DFT-based computational techniques revealed three degradation pathways of SMZ,which were initiated by the deamination reaction at the aniline ring,the breakdown of the sulfonamidemoieties,and a process known as Smile-type rearrangement and SO2 intrusion.Corresponding toxicity of SMZ and the intermediateswere analyzed by quantitative structure activity relationship(QSAR),indicating the effectiveness of LaZnO_(3)-based photocatalysis in preventing secondary pollution of the intermediates to the ecosystem during the degradation process.The visible-light-activated photocatalyst LaZnO_(3) exhibited efficient performance in the occurrence of inorganic anions and maintained high durability across multiple recycling tests,making it a promising candidate for practical antibiotic treatment.
基金supported by the National Natural Science Foundation of China(22271242,22071210,21933004)the Innovation and Technology Commission(ITC-CNERC14SC01)+2 种基金the Research Grants Council of Hong Kong(16309722,16304322,16309023)the Natural Science Foundation of Guangdong Province(2022A1515011859)the Key-Area Research and Development Program of Guangdong Province(2020B010188001).
文摘Organoboron compounds are highly versatile building blocks in modern organic synthesis,pharmaceuticals,and materials science,offering unique reactivity and stability for the assembly of complex molecular structures.The hydroboration of allenes stands out as a straightforward method for the preparation of allyl and alkenyl boranes.Nonetheless,achieving precise control over regio-and stereoselectivity in these reactions presents significant challenges.In this review,we have systematically summarized the selective hydroboration of allenes catalyzed by a range of transition metals,including platinum,copper,palladium,cobalt,nickel,and ruthenium catalysts.The significant advancements,current limitations,and future perspective for the transition metal-catalyzed selective hydroboration are also highlighted.Moreover,we hope that this review will help understand more about the catalytic hydroboration of allenes and stimulate the further development of both allene and organoboron chemistry.
基金supported by the National Natural Science Foundation of China(U1812403 to Xiao-Jiang Hao,2193304 to Yun-Dong Wu,81573323 and 31770392 to Ying-Tong Di,and 22177050 to Ming-Ming Cao)the Project of Yunnan Characteristic Plant Screening and R&D Service CXO Platform(2022YKZY001)the Yunnan Provincial Science and Technology Department(202003AD150012 to Xiao-Jiang Hao,202201AS070040 and 202302AA310035 to Ying-Tong Di)。
文摘In the intricate process of natural product biosynthesis,a metabolon can enhance metabolic flux by associating sequential enzymes.A fungal metabolon,comprising of flavin-dependent monooxygenase Spe F and P450 monooxygenase Spe G,is identified in the biosynthesis of spiro polycyclic alkaloids(+)-notoamide B and its diastereomer(+)-versicolamide B.Using notoamide E as a substance,Spe F/Spe G metabolon can control the stereoselectivity of its 2,3-epoxidation,followed by hydrogen atom ion at C-17 to generate reactive epoxide tau-m A with dienyl iminium unit.Subsequently,(+)-notoamide B and(+)-versicolamide B are produced via tandem nonenzymatic inverse-electron-demand Diels-Alder reaction and semipinacol rearrangement.This provides the first example of metabolon in the biosynthesis of spiro-prenylated indole alkaloids.
文摘By utilizing the classical turning point of the electron movement, we have defined and computed the mo-lecular intrinsic characteristic contour (MICC) via the com-bination of the ab initio quantum chemistry computational method with the ionization potential measured by photo-electron spectroscopy experiment. In this paper, we calcu-lated the MICCs of several small organic molecules contain-ing oxygen atom for the first time. The three-dimensional pictures have been drawn, by performing a large number of calculations. The analysis on some characterized cross-sec-tions of the MICC can provide atomic spatial changing information in the process of forming a molecule.
基金This work was supported by the National Natural Science Foundation of China(Grant No.20073018).
文摘The potential acting on an electron within a molecule (PAEM) is formulated, and then calculated using the ab initio MELD program plus a separate calculation program in the RHF molecular orbital theory, finally the three-dimensional graphs of the potentials have been drawn. We have systematically investigated this kind of the potentials for a series of the diatomic molecules, such as HF, HCl, HBr, LiF, LiCl, and so on. The three-dimensional graph can clearly display the variation of the potential felt by an electron within a molecule and get a deeper understanding of the electronic motion and chemical bonding within a molecule.
基金The authors are grateful for financial support from the Chinese Academy of Science(grant no.XDB20020000)the National Natural Science Foundation of China(no.21933004)+2 种基金the Shenzhen STIC(nos.JCYJ20170412150507046 and JCYJ20170412150343516)the Shenzhen San-Ming Project(no.SZSM201809085)fellowship from the International Postdoctoral Exchange Fellowship Program(no.2020014 to H.C.Shen).
文摘Densely functionalized chiral nitrogen-containing heterocycles are ubiquitous in bioactive synthetic compounds and natural products.Herein,we report a nickel(Ni)-catalyzed enantioselective desymmetrizing aza-Heck cyclization of oxime esters with a commercially available chiral pyridinebis(oxazoline)(pybox)ligand.This reaction proceeds under mild reaction conditions,tolerates various functional groups,and leads to chiral 2-substituted-3,7a-dihydro-3aH-indoles.
