NH_(2)-UIO66(NU)is a promising photocatalyst for the reduction of Cr(VI)to low-toxic Cr(III)driven by visible light under ambient conditions.However,the main limitation in this process is the ineffi cient ligand to me...NH_(2)-UIO66(NU)is a promising photocatalyst for the reduction of Cr(VI)to low-toxic Cr(III)driven by visible light under ambient conditions.However,the main limitation in this process is the ineffi cient ligand to metal charge transfer(LMCT)of photo-excited electrons,which is caused by inherent energy gap(ΔE_(LMCT)).This study synthesized the defective NU(NUXH,where X is the molar equivalent of the modulator)with reducedΔE_(LMCT)through linkers removal via acid treatment.The electronic structure of NUX-H was systematically investigated,and the results indicated that the structural defects in NUX-H strongly altered the environment of the Zr atoms.Furthermore,they substantially lowered the energy of the unoccupied d orbitals(LUMO),which was benefi cial to effi cient LMCT,resulting in an improved photocatalytic activity of NUX-H toward high-concentration(100 mg/L)Cr(VI)reduction.Compared to NU with defect-free structure,the reducing rate of Cr(VI)was increased by 47 times.This work introduced an alternative strategy in terms of designing effi cient photocatalysts for reducing Cr(VI)under ambient conditions.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
Trialkylsilanes are important building blocks in organic synthesis;however,their widespread use in redox chemistry is limited by their high oxidation potentials and comparably high bond dissociation energies(BDEs)of S...Trialkylsilanes are important building blocks in organic synthesis;however,their widespread use in redox chemistry is limited by their high oxidation potentials and comparably high bond dissociation energies(BDEs)of Si-H and α-Si-C-H bonds(>92 kcal mol^(−1)).Herein,we report a new strategy for Si-H bond homolysis enabled by the synergistic combination of electrooxidation,photoinduced ligand-to-metal charge transfer(LMCT),and radical-mediated hydrogen atom transfer(HAT).Governed by the polarity-matching effect,the HAT to electrophilic MeO·or[Cl-OHCH_(3)]·from the more hydridic Si-H instead of a C-H bond allows the selective generation of silyl radicals.This electrophotocatalytic protocol provides rapid access to Si-functionalized benzimidazo-fused isoquinolinones with broad functional-group compatibility.Mechanistic studies have shown that n-Bu_(4)NCl is essential to the electrooxidation of CeCl_(3) to form the Ce(Ⅳ)species.展开更多
We have already studied the interaction of Cu(Ⅱ), Ni(Ⅱ), Zn(Ⅱ), Cd(Ⅱ),Hg(Ⅱ) with HSA (human serum albumin) and BSA (bovine serum albumin). In view of the fact that manganese enzymes and manganese proteins are of ...We have already studied the interaction of Cu(Ⅱ), Ni(Ⅱ), Zn(Ⅱ), Cd(Ⅱ),Hg(Ⅱ) with HSA (human serum albumin) and BSA (bovine serum albumin). In view of the fact that manganese enzymes and manganese proteins are of importance to bioinorganic chemistry, but the research work of interaction between Mn (Ⅱ) with HSA and BSA has not been reported up to now, the present note reports展开更多
基金This work was supported by the National Key Research and Development Program of China(No.2020YFA0211000)the National Natural Science Foundation of China(Nos.21876114,21761142011,and 51572174)+3 种基金the Shanghai Government(Nos.19DZ1205102 and 19160712900)the International Joint Laboratory on Resource Chemistry(No.IJLRC)the Ministry of Education of China(No.PCSIRT_IRT_16R49)This research was also supported by The Program for Professor of Special Appointment(Eastern Scholar)at Shanghai Institutions of Higher Learning,the Shuguang Research Program of Shanghai Education Committee,and the Shanghai Engineering Research Center of Green Energy Chemical Engineering(No.18DZ2254200).
文摘NH_(2)-UIO66(NU)is a promising photocatalyst for the reduction of Cr(VI)to low-toxic Cr(III)driven by visible light under ambient conditions.However,the main limitation in this process is the ineffi cient ligand to metal charge transfer(LMCT)of photo-excited electrons,which is caused by inherent energy gap(ΔE_(LMCT)).This study synthesized the defective NU(NUXH,where X is the molar equivalent of the modulator)with reducedΔE_(LMCT)through linkers removal via acid treatment.The electronic structure of NUX-H was systematically investigated,and the results indicated that the structural defects in NUX-H strongly altered the environment of the Zr atoms.Furthermore,they substantially lowered the energy of the unoccupied d orbitals(LUMO),which was benefi cial to effi cient LMCT,resulting in an improved photocatalytic activity of NUX-H toward high-concentration(100 mg/L)Cr(VI)reduction.Compared to NU with defect-free structure,the reducing rate of Cr(VI)was increased by 47 times.This work introduced an alternative strategy in terms of designing effi cient photocatalysts for reducing Cr(VI)under ambient conditions.
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 grants from the National Key Technology R&D Program(no.2017YFB0307502)the National Natural Science Foundation of China(no.21871019)Beijing Municipal Education Committee Project(nos.KZ202110005003 and KM202110005006).
文摘Trialkylsilanes are important building blocks in organic synthesis;however,their widespread use in redox chemistry is limited by their high oxidation potentials and comparably high bond dissociation energies(BDEs)of Si-H and α-Si-C-H bonds(>92 kcal mol^(−1)).Herein,we report a new strategy for Si-H bond homolysis enabled by the synergistic combination of electrooxidation,photoinduced ligand-to-metal charge transfer(LMCT),and radical-mediated hydrogen atom transfer(HAT).Governed by the polarity-matching effect,the HAT to electrophilic MeO·or[Cl-OHCH_(3)]·from the more hydridic Si-H instead of a C-H bond allows the selective generation of silyl radicals.This electrophotocatalytic protocol provides rapid access to Si-functionalized benzimidazo-fused isoquinolinones with broad functional-group compatibility.Mechanistic studies have shown that n-Bu_(4)NCl is essential to the electrooxidation of CeCl_(3) to form the Ce(Ⅳ)species.
基金Project supported by the National Natural Science Foundation of China.
文摘We have already studied the interaction of Cu(Ⅱ), Ni(Ⅱ), Zn(Ⅱ), Cd(Ⅱ),Hg(Ⅱ) with HSA (human serum albumin) and BSA (bovine serum albumin). In view of the fact that manganese enzymes and manganese proteins are of importance to bioinorganic chemistry, but the research work of interaction between Mn (Ⅱ) with HSA and BSA has not been reported up to now, the present note reports
