Photoinduced ligand-to-metal charge transfer(LMCT) has emerged as an effective strategy for synthesizing organic molecules in a sustainable manner. However, the majority of existing reports on selective C(sp^(3))–H b...Photoinduced ligand-to-metal charge transfer(LMCT) has emerged as an effective strategy for synthesizing organic molecules in a sustainable manner. However, the majority of existing reports on selective C(sp^(3))–H bond functionalization via photoinduced LMCT focus on the use of late transition metals or rare-earth metals for radical additions or cross-couplings. In contrast, the utilization of photoinduced LMCT with 3d early transition metals poses a significant challenge. Herein, we describe an unprecedented approach to allylic C(sp^(3))–H addition to aldehydes, employing chromium(Cr) complexes as catalysts through visible-light-induced LMCT. By investigating the reaction pathway through various mechanistic studies, including radical trapping, kinetic isotope effect(KIE) analysis, and transient absorption spectroscopy, valuable insights have been gained. The proposed mechanism suggests the intermediacy of bromine radicals through homolysis of the Cr–Br bond. Notably, this protocol expands our understanding of the photochemical properties of earth-abundant Cr complexes.展开更多
An atom economicβ-C(sp^(3))−H chlorination of amide derivatives has been developed.This mild protocol employs CuCl_(2) instead of palladium catalysts with atom-economic HCl as chlorine sources and enables the late-st...An atom economicβ-C(sp^(3))−H chlorination of amide derivatives has been developed.This mild protocol employs CuCl_(2) instead of palladium catalysts with atom-economic HCl as chlorine sources and enables the late-stage functionalization of medicine derivatives.Mechanism studies suggest a plausible visible light triggered ligand-to-metal charge transfer(LMCT)/1,4-hydrogen atom transfer(HAT)cascade.展开更多
Owing to its outstanding photoactivity,ferrioxalate is originally used as an actinometer and subsequent work has discovered that photochemistry of ferrioxalate is also fundamentally or technically important in atmosph...Owing to its outstanding photoactivity,ferrioxalate is originally used as an actinometer and subsequent work has discovered that photochemistry of ferrioxalate is also fundamentally or technically important in atmospheric chemistry and water treatment.While the overall products generated from photolysis of ferrioxalate are known to include Fe(Ⅱ),a series of oxidizing(e.g.,·OH,O_(2)^(·-)/HO_(2)^(·-))or reducing(C_(2)O_(4)^(·-)/CO_(2)^(·-))radicals and H_(2)O_(2),however,at the molecular level,the primary step of the photoreaction of ferrioxalate remains as an unsolved mystery due to the difficulty in examining such ultrafast processes.Benefiting from the development of time-resolved spectroscopy,this old question has been studied with increasing vigor recently,by means of such ever-more-sophisticated techniques(e.g.,flash photolysis,time-resolved X-ray absorption spectroscopy(XAS),femtosecond infrared(IR)absorption spectroscopy,ultrafast photoelectron spectroscopy(PES)).There are two contrary views on the primary reaction mechanism:(1)Intramolecular electron transfer(ET)precedes the cleavage of the metal-ligand bond;(2)The dissociation of C-C or Fe-O bond occurs before intramolecular ET.Thus,this review presents a comprehensive summary about the overall reaction mechanism and molecular level mechanism of ferrioxalates.In chronological order,we have elaborated two predominant but controversial views from the perspectives of different experimental approaches.Some challenges and research opportunities in this active field are also briefly discussed.展开更多
A novel 3 D bismuth-organic framework(called Bi-TBAPy) single crystal was synthesized by employing 1,3,6,8-tetrakis(p-benzoic acid)pyrene(H4TBAPy) as an organic linker. The study demonstrates that the Bi-TBAPy not onl...A novel 3 D bismuth-organic framework(called Bi-TBAPy) single crystal was synthesized by employing 1,3,6,8-tetrakis(p-benzoic acid)pyrene(H4TBAPy) as an organic linker. The study demonstrates that the Bi-TBAPy not only possesses good chemical stability and suitable band edge positions for promising photocatalytic H2 evolution, but it also exhibits a typical ligand-to-metal charge transfer for favorable charge separation. The photocatalytic H2 evolution rates on the as-obtained Bi-TBAPy with different cocatalysts modified were examined with triethanolamine as the sacrificial reagent. Based on this, the hydrogen evolution rate of 140 μmol h-1 g-1 was obtained on the optimized sample with a loading of 2 wt% Pt as a cocatalyst. To the best of our knowledge, this is the first bismuth-based metal-organic framework(MOF) that functions as an effective photocatalyst for photocatalytic water reduction. Our study not only adds a new member to the family of photocatalyst materials, but also reveals the importance of cocatalyst modification in improving photocatalytic activity of MOFs.展开更多
Treatment of antibiotics contaminated water remains a global environmental challenge.In this study,tetracycline(TC)was found to effectively sensitize pure TiO_(2) for visible light photocatalytic degradation via a lig...Treatment of antibiotics contaminated water remains a global environmental challenge.In this study,tetracycline(TC)was found to effectively sensitize pure TiO_(2) for visible light photocatalytic degradation via a ligand-to-metal charge transfer mechanism.The sensitization was attributed to the formation of TC-TiO_(2) complex and the overlap of the molecular orbitals of TC and the conduction band of TiO_(2).The intermediate degradation products of TC,however,did not sensitize TiO_(2),which was the reason for the low mineralization rate.Nevertheless,our results showed that the intermediate degradation products of TC had significantly reduced bactericidal effects and less induction of antibiotic-resistance genes(ARGs).This study showcases an effective treatment of antibiotics-containing wastewater using the most common photocatalyst TiO_(2) with reduced risk in the spread of ARGs.展开更多
Developing visible light responsive(VLR)TiO_(2) photocatalysts is essential and attractive for the consideration of solar energy utilization.A large amount of work have shown TiO_(2) modified with several nonmetal ele...Developing visible light responsive(VLR)TiO_(2) photocatalysts is essential and attractive for the consideration of solar energy utilization.A large amount of work have shown TiO_(2) modified with several nonmetal elements having VLR performance,although according to DFT calculation,Asahi denied the VLR properties of fluorine,carbon,etc.in doping TiO_(2).Therefore,the origins of VLR activity desire further delicate discussion.In this mini-review,several strategies for VLR TiO_(2) modification have been introduced,including N doping or B/N codoping,surface modification with sensitizing matter such as carbonaceous or other organic substances,surface alkoxyls modification via a ligand-to-metal charge transfer(LMCT)process,and enhanced dye sensitization by fluorine modification.Besides doping,there are much more approaches to fabricate VLR TiO_(2) modified with nonmetal elements.However,it is still in demand to explore new methods to obtain more stable and efficient VLR TiO_(2) for practical application.展开更多
Recent progress in the research of radical anion ligands and their complexes with metals were summarized in this review.Radical anions were sorted into several types including iminosemiquinonate and iminoquinonate rad...Recent progress in the research of radical anion ligands and their complexes with metals were summarized in this review.Radical anions were sorted into several types including iminosemiquinonate and iminoquinonate radical,nitroxide radical,heterocycle radical etc.Structural characteristics and properties of the corresponding complexes were introduced.The complexes exhibited novel properties and possibility for applications in organic magnetic materials and transition metal catalysis.展开更多
The binding mode and configuration of cisplatin with F-actin were studied on the basis of charge transfer bands of cisplatin-F-actin complex The binding mode was discussed on the basis of the results of LMCT.Raman and...The binding mode and configuration of cisplatin with F-actin were studied on the basis of charge transfer bands of cisplatin-F-actin complex The binding mode was discussed on the basis of the results of LMCT.Raman and fluorescence spectra.展开更多
The hydrothermal reaction of 5-methoxyisophthalic acid（MeO-H2ip）, 1,3-bis（2-methylimidazol-1-yl）propane（bmip） and Zn（NO3）2·6H2O in the presence of NaOCH3 gave rise to a three-dimensional（3-D） metal-orga...The hydrothermal reaction of 5-methoxyisophthalic acid（MeO-H2ip）, 1,3-bis（2-methylimidazol-1-yl）propane（bmip） and Zn（NO3）2·6H2O in the presence of NaOCH3 gave rise to a three-dimensional（3-D） metal-organic framework containing octanuclear Zn（II） units, [Zn4（MeO-ip）3（OH）2（bmip）]n. Single-crystal X-ray diffraction analysis reveals that the complex crystallizes in the triclinic space group P1 with a = 11.348（3）, b = 14.163（4）, c = 15.088（4） , α = 108.537（2）, β = 106.542（2）, γ = 103.106（1）o, V = 2065.4（9） -3, Z = 2, Mr = 334.62, Dc = 1.740 g·cm-（-3）, μ = 2.375 mm-（-1）, S = 1.015, F（000） = 1096, the final R = 0.0272 and w R = 0.0715 for 8929 observed reflections（I 〉 2σ（I））. The complex is thermally stable up to 370 oC, and exhibits photoluminescent emission at 450 nm on 350 nm excitation.展开更多
基金supported by the National Natural Science Foundation of China (22001215, 22171231)WE-Syn Bio Center at Westlake University (WU2022A007)Zhejiang Leading Innovative and Entrepreneur Team Introduction Program (2020R01004)。
文摘Photoinduced ligand-to-metal charge transfer(LMCT) has emerged as an effective strategy for synthesizing organic molecules in a sustainable manner. However, the majority of existing reports on selective C(sp^(3))–H bond functionalization via photoinduced LMCT focus on the use of late transition metals or rare-earth metals for radical additions or cross-couplings. In contrast, the utilization of photoinduced LMCT with 3d early transition metals poses a significant challenge. Herein, we describe an unprecedented approach to allylic C(sp^(3))–H addition to aldehydes, employing chromium(Cr) complexes as catalysts through visible-light-induced LMCT. By investigating the reaction pathway through various mechanistic studies, including radical trapping, kinetic isotope effect(KIE) analysis, and transient absorption spectroscopy, valuable insights have been gained. The proposed mechanism suggests the intermediacy of bromine radicals through homolysis of the Cr–Br bond. Notably, this protocol expands our understanding of the photochemical properties of earth-abundant Cr complexes.
基金support from the University Nursing Program for Young Scholars with Creative Talents in Heilongjiang Province(No.UNPYSCT-2017124).
文摘An atom economicβ-C(sp^(3))−H chlorination of amide derivatives has been developed.This mild protocol employs CuCl_(2) instead of palladium catalysts with atom-economic HCl as chlorine sources and enables the late-stage functionalization of medicine derivatives.Mechanism studies suggest a plausible visible light triggered ligand-to-metal charge transfer(LMCT)/1,4-hydrogen atom transfer(HAT)cascade.
基金supported by the National Natural Science Foundation of China(No.41977313)the support from the Foundation of Key Laboratory of Yangtze River Water Environment,Ministry of Education(Tongji University),China(No.YRWEF202003)Key Laboratory of Eco-geochemistry,Ministry of Natural Resources(No.ZSDHJJ202006)。
文摘Owing to its outstanding photoactivity,ferrioxalate is originally used as an actinometer and subsequent work has discovered that photochemistry of ferrioxalate is also fundamentally or technically important in atmospheric chemistry and water treatment.While the overall products generated from photolysis of ferrioxalate are known to include Fe(Ⅱ),a series of oxidizing(e.g.,·OH,O_(2)^(·-)/HO_(2)^(·-))or reducing(C_(2)O_(4)^(·-)/CO_(2)^(·-))radicals and H_(2)O_(2),however,at the molecular level,the primary step of the photoreaction of ferrioxalate remains as an unsolved mystery due to the difficulty in examining such ultrafast processes.Benefiting from the development of time-resolved spectroscopy,this old question has been studied with increasing vigor recently,by means of such ever-more-sophisticated techniques(e.g.,flash photolysis,time-resolved X-ray absorption spectroscopy(XAS),femtosecond infrared(IR)absorption spectroscopy,ultrafast photoelectron spectroscopy(PES)).There are two contrary views on the primary reaction mechanism:(1)Intramolecular electron transfer(ET)precedes the cleavage of the metal-ligand bond;(2)The dissociation of C-C or Fe-O bond occurs before intramolecular ET.Thus,this review presents a comprehensive summary about the overall reaction mechanism and molecular level mechanism of ferrioxalates.In chronological order,we have elaborated two predominant but controversial views from the perspectives of different experimental approaches.Some challenges and research opportunities in this active field are also briefly discussed.
基金supported by the National Natural Science Foundation of China(21633009,21522306,21633010)DICP&QIBEBT(UN201805)the Dalian Science Foundation for Distinguished Young Scholars(2017RJ02)~~
文摘A novel 3 D bismuth-organic framework(called Bi-TBAPy) single crystal was synthesized by employing 1,3,6,8-tetrakis(p-benzoic acid)pyrene(H4TBAPy) as an organic linker. The study demonstrates that the Bi-TBAPy not only possesses good chemical stability and suitable band edge positions for promising photocatalytic H2 evolution, but it also exhibits a typical ligand-to-metal charge transfer for favorable charge separation. The photocatalytic H2 evolution rates on the as-obtained Bi-TBAPy with different cocatalysts modified were examined with triethanolamine as the sacrificial reagent. Based on this, the hydrogen evolution rate of 140 μmol h-1 g-1 was obtained on the optimized sample with a loading of 2 wt% Pt as a cocatalyst. To the best of our knowledge, this is the first bismuth-based metal-organic framework(MOF) that functions as an effective photocatalyst for photocatalytic water reduction. Our study not only adds a new member to the family of photocatalyst materials, but also reveals the importance of cocatalyst modification in improving photocatalytic activity of MOFs.
基金support from the National Natural Science Foundation of China(No.21777116)the Fundamental Research Funds for the Central Universities.
文摘Treatment of antibiotics contaminated water remains a global environmental challenge.In this study,tetracycline(TC)was found to effectively sensitize pure TiO_(2) for visible light photocatalytic degradation via a ligand-to-metal charge transfer mechanism.The sensitization was attributed to the formation of TC-TiO_(2) complex and the overlap of the molecular orbitals of TC and the conduction band of TiO_(2).The intermediate degradation products of TC,however,did not sensitize TiO_(2),which was the reason for the low mineralization rate.Nevertheless,our results showed that the intermediate degradation products of TC had significantly reduced bactericidal effects and less induction of antibiotic-resistance genes(ARGs).This study showcases an effective treatment of antibiotics-containing wastewater using the most common photocatalyst TiO_(2) with reduced risk in the spread of ARGs.
基金This work was supported by the National Natural Science Foundation of China(Grant No.20907031)the State Key Laboratory for Modification of Chemical Fibers and Polymer Materials,Dong Hua University(Grant No.LK0907)the Specialized Research Fund for the Doctoral Program of Higher Education(Grant No.20090073120042).
文摘Developing visible light responsive(VLR)TiO_(2) photocatalysts is essential and attractive for the consideration of solar energy utilization.A large amount of work have shown TiO_(2) modified with several nonmetal elements having VLR performance,although according to DFT calculation,Asahi denied the VLR properties of fluorine,carbon,etc.in doping TiO_(2).Therefore,the origins of VLR activity desire further delicate discussion.In this mini-review,several strategies for VLR TiO_(2) modification have been introduced,including N doping or B/N codoping,surface modification with sensitizing matter such as carbonaceous or other organic substances,surface alkoxyls modification via a ligand-to-metal charge transfer(LMCT)process,and enhanced dye sensitization by fluorine modification.Besides doping,there are much more approaches to fabricate VLR TiO_(2) modified with nonmetal elements.However,it is still in demand to explore new methods to obtain more stable and efficient VLR TiO_(2) for practical application.
基金supported by the National Natural Science Foundation of China(20972025,U1362110)PetroChina Innovation Foundation(2013D-5006-0503)+2 种基金Scientific Research Foundation for the Returned Overseas Chinese Scholars,Program for New Century Excellent Talents in University(NCET-07-0142)Heilongjiang Province(41417837-8-08016)Department of Education of Heilongjiang Province(1154H14,1154G53)
文摘Recent progress in the research of radical anion ligands and their complexes with metals were summarized in this review.Radical anions were sorted into several types including iminosemiquinonate and iminoquinonate radical,nitroxide radical,heterocycle radical etc.Structural characteristics and properties of the corresponding complexes were introduced.The complexes exhibited novel properties and possibility for applications in organic magnetic materials and transition metal catalysis.
文摘The binding mode and configuration of cisplatin with F-actin were studied on the basis of charge transfer bands of cisplatin-F-actin complex The binding mode was discussed on the basis of the results of LMCT.Raman and fluorescence spectra.
基金supported by the Natural Science Foundation of Fujian Province(2015J01038)Provincial Education Department of Fujian(JA12070)State Key Laboratory of Structural Chemistry(20150015)
文摘The hydrothermal reaction of 5-methoxyisophthalic acid（MeO-H2ip）, 1,3-bis（2-methylimidazol-1-yl）propane（bmip） and Zn（NO3）2·6H2O in the presence of NaOCH3 gave rise to a three-dimensional（3-D） metal-organic framework containing octanuclear Zn（II） units, [Zn4（MeO-ip）3（OH）2（bmip）]n. Single-crystal X-ray diffraction analysis reveals that the complex crystallizes in the triclinic space group P1 with a = 11.348（3）, b = 14.163（4）, c = 15.088（4） , α = 108.537（2）, β = 106.542（2）, γ = 103.106（1）o, V = 2065.4（9） -3, Z = 2, Mr = 334.62, Dc = 1.740 g·cm-（-3）, μ = 2.375 mm-（-1）, S = 1.015, F（000） = 1096, the final R = 0.0272 and w R = 0.0715 for 8929 observed reflections（I 〉 2σ（I））. The complex is thermally stable up to 370 oC, and exhibits photoluminescent emission at 450 nm on 350 nm excitation.
