Two host-guest systems have been constructed,by employing structurally similar terpyridine platinum(II)macrocycle and molecular tweezer as the synthetic receptors.The macrocycle/guest complex displays low-energy emiss...Two host-guest systems have been constructed,by employing structurally similar terpyridine platinum(II)macrocycle and molecular tweezer as the synthetic receptors.The macrocycle/guest complex displays low-energy emission signal,reinforced non-covalent binding affinity,and enhanced photosensitization capability than those of the molecular tweezer/guest one.The discrepancy between macrocyclic and acyclic preorganization modes originates from the different numbers of Pt(II)Pt(II)metal-metal bonds in host-guest complexation structures.展开更多
Isolation of RuⅢ-bda(17-electron specie)complex with an aqua ligand(2-electron donor)is challenging due to violation of the 18-electron rule.Although considerable efforts have been dedicated to mechanistic studies of...Isolation of RuⅢ-bda(17-electron specie)complex with an aqua ligand(2-electron donor)is challenging due to violation of the 18-electron rule.Although considerable efforts have been dedicated to mechanistic studies of water oxidation by the Ru-bda family,the structure and initial formation of the Ru^(Ⅲ)-bda aqua complex are still controversial.Herein,we challenge this often overlooked step by designing a pocketshape Ru-based complex 1.The computational studies showed that 1 possesses the crucial hydrophobicity at the Ru^(V)(O)state as well as similar probability of access of terminal O to solvent water molecules when compared with classic Ru-bda catalysts.Through characterization of single-crystal structures at the Ru^(Ⅱ) and Ru^(Ⅲ) states,a pseudo seven-coordinate“ready-togo”aqua ligand with Ru^(Ⅲ)…O distance of 3.62A was observed.This aqua ligand was also found to be part of a formed hydrogen-bonding network,providing a good indication of how the Ru^(Ⅲ)-OH_(2)complex is formed.展开更多
Here we report a new one-step thermal polycondensation process to form crinkly graphitic carbon nitride nanosheets(CGCNNs)via supramolecular preorganization,using a mixture of urea and melamine as the starting materia...Here we report a new one-step thermal polycondensation process to form crinkly graphitic carbon nitride nanosheets(CGCNNs)via supramolecular preorganization,using a mixture of urea and melamine as the starting material.Systematical studies reveal that the newly developed CGCNNs significantly strengthen the optical absorption,widen the bandgap,and increase the Hall mobility and carrier density compared to that of its bulk counterpart,regardless of the similar chemical composition and structure.As a result,the photocatalytic hydrogen production rate is improved by 7 times.Moreover,Na doping of CGCNNs can further promote its photocatalytic activity,leading to an excellent photocatalytic hydrogen production rate of 250.9μmol h^(–1),which is approximately 10.5 times higher than its bulk counterpart.Moreover,an impressive apparent quantum efficiency of 19.12%is achieved at 420 nm.This study provides a facile strategy for the design of efficient low-cost carbon-nitride-based photocatalysts for solar fuel production.展开更多
The creation of artificial enzymes to mimic natural enzymes remains a great challenge owing to the complexity of the structural arrangement of the essential amino acids in catalytic centers.In this study,we used the p...The creation of artificial enzymes to mimic natural enzymes remains a great challenge owing to the complexity of the structural arrangement of the essential amino acids in catalytic centers.In this study,we used the phosphatase-based enzyme-instructed self-assembly(EISA)to supervise artificial esterases'final structures and catalytic activities.We reported that peptide precursors containing different phosphorylation sites could preorganize into alternated nanostructures and undergo dephosphorylation in the presence of alkaline phosphatase(ALP)with variation in kinetic and thermodynamic profiles.Although identical self-assembly compositions were formed after dephosphorylation,precursors with more enhanced preorganized states tended to better promote ALP dephosphorylation,facilitate further self-assembly,and strengthen the catalytic activities of the final assemblies.We envisioned that our strategy would be useful for further construction and manipulation of various artificial enzymes with superior catalytic activities.展开更多
基金supported by the National Natural Science Foundation of China(Nos.21674106 and 21871245)CAS Youth Innovation Promotion Association(No.2015365)the Fundamental Research Funds for the Central Universities(No.WK3450000004)
文摘Two host-guest systems have been constructed,by employing structurally similar terpyridine platinum(II)macrocycle and molecular tweezer as the synthetic receptors.The macrocycle/guest complex displays low-energy emission signal,reinforced non-covalent binding affinity,and enhanced photosensitization capability than those of the molecular tweezer/guest one.The discrepancy between macrocyclic and acyclic preorganization modes originates from the different numbers of Pt(II)Pt(II)metal-metal bonds in host-guest complexation structures.
基金financially supported by the Swedish Research Council(2017-00935)the Knut and Alice Wallenberg Foundation(KAW 2016.0072)the China Scholarship Council(CSC).
文摘Isolation of RuⅢ-bda(17-electron specie)complex with an aqua ligand(2-electron donor)is challenging due to violation of the 18-electron rule.Although considerable efforts have been dedicated to mechanistic studies of water oxidation by the Ru-bda family,the structure and initial formation of the Ru^(Ⅲ)-bda aqua complex are still controversial.Herein,we challenge this often overlooked step by designing a pocketshape Ru-based complex 1.The computational studies showed that 1 possesses the crucial hydrophobicity at the Ru^(V)(O)state as well as similar probability of access of terminal O to solvent water molecules when compared with classic Ru-bda catalysts.Through characterization of single-crystal structures at the Ru^(Ⅱ) and Ru^(Ⅲ) states,a pseudo seven-coordinate“ready-togo”aqua ligand with Ru^(Ⅲ)…O distance of 3.62A was observed.This aqua ligand was also found to be part of a formed hydrogen-bonding network,providing a good indication of how the Ru^(Ⅲ)-OH_(2)complex is formed.
基金financial support from the National Natural Science Foundation of China(No.52002328)the Fundamental Research Funds for the Central Universities+1 种基金the Joint Research Funds of Department of Science&Technology of Shaanxi Province and Northwestern Polytechnical University(2020GXLH-Z018)the Australian Research Council through its Discovery Projects(DPs)and Laureate Fellowship。
文摘Here we report a new one-step thermal polycondensation process to form crinkly graphitic carbon nitride nanosheets(CGCNNs)via supramolecular preorganization,using a mixture of urea and melamine as the starting material.Systematical studies reveal that the newly developed CGCNNs significantly strengthen the optical absorption,widen the bandgap,and increase the Hall mobility and carrier density compared to that of its bulk counterpart,regardless of the similar chemical composition and structure.As a result,the photocatalytic hydrogen production rate is improved by 7 times.Moreover,Na doping of CGCNNs can further promote its photocatalytic activity,leading to an excellent photocatalytic hydrogen production rate of 250.9μmol h^(–1),which is approximately 10.5 times higher than its bulk counterpart.Moreover,an impressive apparent quantum efficiency of 19.12%is achieved at 420 nm.This study provides a facile strategy for the design of efficient low-cost carbon-nitride-based photocatalysts for solar fuel production.
基金National Natural Science Foundation of China (No.20921091,20732007,20974118,20872167)Ministry of Science and Technology of China (No.2007CB-808001)Science and Technology Commission of Shanghai Municipality (No.09XD1405300)for financial support
基金supported by the National Science Fund for Distinguished Young Scholars(31825012)the National Natural Science Foundation of China(21875116,31961143004,81921004)+1 种基金the National Key Research and Development Program of China(2017YFC1103502,2018YFC1003401)the China Postdoctoral Science Foundation(2020M680856)。
文摘The creation of artificial enzymes to mimic natural enzymes remains a great challenge owing to the complexity of the structural arrangement of the essential amino acids in catalytic centers.In this study,we used the phosphatase-based enzyme-instructed self-assembly(EISA)to supervise artificial esterases'final structures and catalytic activities.We reported that peptide precursors containing different phosphorylation sites could preorganize into alternated nanostructures and undergo dephosphorylation in the presence of alkaline phosphatase(ALP)with variation in kinetic and thermodynamic profiles.Although identical self-assembly compositions were formed after dephosphorylation,precursors with more enhanced preorganized states tended to better promote ALP dephosphorylation,facilitate further self-assembly,and strengthen the catalytic activities of the final assemblies.We envisioned that our strategy would be useful for further construction and manipulation of various artificial enzymes with superior catalytic activities.
