The coordination engineering of catalytic centers emerges as a pivotal strategy for precise electronic configuration modulation in photocatalytic CO_(2) reduction.Herein,the electronic structure of active sites in pol...The coordination engineering of catalytic centers emerges as a pivotal strategy for precise electronic configuration modulation in photocatalytic CO_(2) reduction.Herein,the electronic structure of active sites in polypyridine nickel catalysts is well modified through strategic ligand variation(bipyridine,terpyridine(TPY),2,6-di(1-pyrazolyl)pyridine)and anion coordination(NO_(3)^(-),Cl^(-),and CH_(3)COO^(-)),achieving enhanced CO_(2) performance.Crucially,covalent immobilization of these molecular catalysts within the COF-OH framework not only preserves their precisely defined and structurally adaptable characteristics but also demonstrates synergistic enhancement of CO_(2) adsorption capacity and charge transfer kinetics,as verified by CO_(2) adsorption isothermal analysis and ultrafast time-resolved transient absorption spectroscopy.Remarkably,COF-O-TPYNi(NO_(3)^(-))catalyst exhibits a CO_(2)-to-CO reduction activity of 9006.0μmol·g^(-1)·h^(-1)with 95.9%selectivity,superior to its counterpart catalysts,directly validating the mechanistic significance of precisely tailored coordination microenvironments around Ni active sites.Mechanistic studies through in situ XAFS,in situ ATR-SEIRAS and theoretical calculations reveal that this performance improvement over COF-O-TPYNi(NO_(3)^(-))is attributed to the reduced reaction energy barrier of*COOH generation.This work pioneers a coordination shell engineering paradigm for rational design of molecularly defined catalytic architectures.展开更多
Two new ruthenium polypyridine complexes. L2RuL2+ where L=2,2'-bipyridine (bpy) and 2, 9-dimethyl-1. 10-phenanthroline (dmp); L' is Schiff base prepared from condensation of 4. 5 diazafluoren-9-one (AFO) and a...Two new ruthenium polypyridine complexes. L2RuL2+ where L=2,2'-bipyridine (bpy) and 2, 9-dimethyl-1. 10-phenanthroline (dmp); L' is Schiff base prepared from condensation of 4. 5 diazafluoren-9-one (AFO) and aniline. have been prepared and characterized by elemental analyses, electronic absorption, IR spectra. The binding of the complexes to calf thymus DNA has beeninvestics by absorption. emission spectra and circular dichroism spectroscopy. Experimental results show these two complexes bind to DNA by electrostatic mode and non-interactive binding mode.展开更多
Two new ruthenium polypyridine complexes, L 2RuL 2+ (L represents 2,2 bipyridine(bpy) or 1,10 phenanthroline(phen); L represents Schiff base derived from 4,5 diazafluoren 9 one(AFO) and n propylamine)...Two new ruthenium polypyridine complexes, L 2RuL 2+ (L represents 2,2 bipyridine(bpy) or 1,10 phenanthroline(phen); L represents Schiff base derived from 4,5 diazafluoren 9 one(AFO) and n propylamine) have been prepared and characterized by means of elementary analyses, electronic absorption and IR spectra. The binding of the complexes to calf thymus DNA has been investigated via absorption, emission spectrometry, emission quenching, equilibrium dialysis and circular dichroism spectrometry. The experimental results show that these two complexes bind to calf thymus DNA by electrostatic mode and by non intercalative binding mode respectively.展开更多
Some novel polypyridine ligands containing adsorbing groups were synthesized with the purpose of developing new ruthenium(II) polypyridine complexes to be used in solar cell based on dye-sensitized nanocrystilline TiO...Some novel polypyridine ligands containing adsorbing groups were synthesized with the purpose of developing new ruthenium(II) polypyridine complexes to be used in solar cell based on dye-sensitized nanocrystilline TiO2 film electrode.展开更多
Bacterial infections seriously jeopardize human life and health.Photodynamic therapy(PDT),as an emerging noninvasive antibacterial strategy,has proven to be an effective treatment method against bacterial resistance.H...Bacterial infections seriously jeopardize human life and health.Photodynamic therapy(PDT),as an emerging noninvasive antibacterial strategy,has proven to be an effective treatment method against bacterial resistance.However,current photosensitizers suffer from inadequate free radical generation and limited functionality.To address this issue,a newπ-conjugated viologen derivative,3TPhDPyMeOTf,was designed.This derivative with multiple thiophene units enhances visible light absorption,and the presence of multiple pyridine structures allows the photosensitizer to generate more free radicals.Experimental and theoretical studies have demonstrated its inhibitory effect on bacterial growth both in vitro and in vivo,demonstrating a broad-spectrum antibacterial effect.The photosensitizer also exhibits excellent bacterial membrane staining,making it suitable for bacterial imaging.The design of this photosensitizer provides a new direction for the development of potent photosensitizers and photodynamic therapy.展开更多
V_(3)O_(7)·H_(2)O(VO)is a high capacity cathode material in the field of aqueous zinc ion batteries(AZIBs),but it is limited by slow ion migration and low electrical conductivity.In this paper,polypyridine(PPyd)i...V_(3)O_(7)·H_(2)O(VO)is a high capacity cathode material in the field of aqueous zinc ion batteries(AZIBs),but it is limited by slow ion migration and low electrical conductivity.In this paper,polypyridine(PPyd)intercalated VO with nanoribbon structure was prepared by a simple in-situ pre-intercalation,which is noted VO-PPyd.The total density of states(TDOS)shows that after the pre-intercalation of PPyd,an intermediate energy level appears between the valence band and conduction band,which provides a step that can effectively reduce the band gap and enhance the electron conductivity.Furthermore,the density functional theory(DFT)results found that Zn^(2+)is more easily de-intercalated from the V-O skeleton,which proves that the embeddedness of PPyd improves the diffusion kinetics of Zn^(2+).Electrochemical studies have shown that VO-PPyd cathode materials exhibit excellent rate performance(high specific capacity of 465 and 192 mA h g^(-1)at 0.2 and 10 A g^(-1),respectively)and long-term cycling performance(92.7%capacity retention rate after 5300 cycles),due to their advantages in structure and composition.More importantly,the energy density of VO-PPyd//Zn at 581 and 5806 W kg^(-1)is 375 and 247 W h kg^(-1),respectively.VO-PPyd exhibits excellent electrochemical properties compared to previously reported vanadium based cathodes,which makes it highly competitive in the field of high-performance cathode materials of AZIBs.展开更多
Two homogeneous photoelectrocatalytic systems composed of simple polypyridyl Co complexes[Co(tpy)2](PF6)2and[Co(bpy)3](PF6)2as electrocatalysts and a Si wafer as the photoelectrode were used for combined photoelectroc...Two homogeneous photoelectrocatalytic systems composed of simple polypyridyl Co complexes[Co(tpy)2](PF6)2and[Co(bpy)3](PF6)2as electrocatalysts and a Si wafer as the photoelectrode were used for combined photoelectrochemical reduction of CO2to CO.A high photocurrent density of1.4mA/cm2was observed for the system with the[Co(tpy)2](PF6)2catalyst and a photovoltage of400mV was generated.Faradaic efficiencies of CO were optimized to83%and94%for the[Co(tpy)2](PF6)2and[Co(bpy)3](PF6)2complexes,respectively,in acetonitrile solution with10%methanol(volume fraction,same below)as a protic additive.Addition of2%water volume fraction induced a large amount of non‐specific H2evolution by the Si photoelectrode.展开更多
A novel compound, （E）-4′-（4-（but-1-en-3-ynyl）phenyl）-2,2′：6′,2″-terpyridine 1 was synthesized from 4′-（4-bromomethylphenyl）-2,2P：6P,2PP-terpyridine phosphonium salt 2 and propargylaldehyde via Wittig re...A novel compound, （E）-4′-（4-（but-1-en-3-ynyl）phenyl）-2,2′：6′,2″-terpyridine 1 was synthesized from 4′-（4-bromomethylphenyl）-2,2P：6P,2PP-terpyridine phosphonium salt 2 and propargylaldehyde via Wittig reaction, and characterized by EI-MS and ^1H NMR as well as elemental analysis. The spectral changes of the compound in the presence of transition metal ions, such as Cu（I） or Zn（ID, are investigated.展开更多
In a carbon dioxide reduction reaction(CO_(2)RR),metal carbonyl intermediate not only serves as the 2e-/2H+reduction product,but it also contributes to CO release for catalyst regeneration.In the past decade,a large n...In a carbon dioxide reduction reaction(CO_(2)RR),metal carbonyl intermediate not only serves as the 2e-/2H+reduction product,but it also contributes to CO release for catalyst regeneration.In the past decade,a large number of studies have demonstrated that a catalyst binds,activates,and achieves electron transfer to CO_(2).However,the formation of metal carbonyl intermediate and release of CO during the CO_(2)RR process have not received the same level of attention.Herein,three iron(Ⅱ)complexes are designed to help us to understand the activation of CO_(2)and release of CO.Our research reveals that by removing one of the axial pyridine ligands from polypyridyl-iron(Ⅱ)complex 3,the favorable H2O coordination greatly decreases the activation energy of C-O bond cleavage of complex 1 and 2,and the resultant high-spin Fe(II)carbonyl intermediate with weaker ligand field dramatically reduces CO binding affinity and improves the faradaic efficiency from∼17%to 90%in catalytic CO_(2)RR.展开更多
A series of polypyridine ruthenium （II） acetylide complexes, [（tpy）（bpy）RuC≡CC6H4R]^＋ （tpy = 2,2＇：6＇,2＂-terpyridine, bpy = 2,2＇-bipyridine; R = F （1）, C1 （2）, H （3）, Me （4） and OMe （5）） are in...A series of polypyridine ruthenium （II） acetylide complexes, [（tpy）（bpy）RuC≡CC6H4R]^＋ （tpy = 2,2＇：6＇,2＂-terpyridine, bpy = 2,2＇-bipyridine; R = F （1）, C1 （2）, H （3）, Me （4） and OMe （5）） are investigated theoretically to explore their electronic structures and spectroscopic properties. Their ground/excited state geometries, electronic structures and spectroscopic properties are first calculated using density functional theory （DFT） and time-dependent DFT （TDDFT）. The absorption and emission spectra of the complexes in acetonitrile solution are also obtained by using TDDFT （B3LYP） method associated with the CPCM model. The calculations show that the energy levels of HOMOs for 1-5 are sensitive to the substituent on phenylacetylide ligand and increase with the same order of the electron-donating ability of the substituents; however, those of polypyridine-based LUMOs vary slightly. The lowest-energy absorptions and emissions for 1-5 are progressively red-shifted in the order of 1 ~ 2 〈 3 〈 4 〈 5 when the electron-donating groups are introduced into the phenylacetylide [igand. The phosphorescence of 1 are attributed to {[dxz（Ru） ＋π（C≡C）]→[π^＊（tpy）]} （3MLCT/3LLCT） transition, whereas those of 2-5 are originated from { [dxz/dxy（Ru）＋ π（C ≡C）＋g（C6H4R）] → [＊（tpy/bpy）] } （3MLCT/3LLCT） transitions.展开更多
文摘The coordination engineering of catalytic centers emerges as a pivotal strategy for precise electronic configuration modulation in photocatalytic CO_(2) reduction.Herein,the electronic structure of active sites in polypyridine nickel catalysts is well modified through strategic ligand variation(bipyridine,terpyridine(TPY),2,6-di(1-pyrazolyl)pyridine)and anion coordination(NO_(3)^(-),Cl^(-),and CH_(3)COO^(-)),achieving enhanced CO_(2) performance.Crucially,covalent immobilization of these molecular catalysts within the COF-OH framework not only preserves their precisely defined and structurally adaptable characteristics but also demonstrates synergistic enhancement of CO_(2) adsorption capacity and charge transfer kinetics,as verified by CO_(2) adsorption isothermal analysis and ultrafast time-resolved transient absorption spectroscopy.Remarkably,COF-O-TPYNi(NO_(3)^(-))catalyst exhibits a CO_(2)-to-CO reduction activity of 9006.0μmol·g^(-1)·h^(-1)with 95.9%selectivity,superior to its counterpart catalysts,directly validating the mechanistic significance of precisely tailored coordination microenvironments around Ni active sites.Mechanistic studies through in situ XAFS,in situ ATR-SEIRAS and theoretical calculations reveal that this performance improvement over COF-O-TPYNi(NO_(3)^(-))is attributed to the reduced reaction energy barrier of*COOH generation.This work pioneers a coordination shell engineering paradigm for rational design of molecularly defined catalytic architectures.
文摘Two new ruthenium polypyridine complexes. L2RuL2+ where L=2,2'-bipyridine (bpy) and 2, 9-dimethyl-1. 10-phenanthroline (dmp); L' is Schiff base prepared from condensation of 4. 5 diazafluoren-9-one (AFO) and aniline. have been prepared and characterized by elemental analyses, electronic absorption, IR spectra. The binding of the complexes to calf thymus DNA has beeninvestics by absorption. emission spectra and circular dichroism spectroscopy. Experimental results show these two complexes bind to DNA by electrostatic mode and non-interactive binding mode.
文摘Two new ruthenium polypyridine complexes, L 2RuL 2+ (L represents 2,2 bipyridine(bpy) or 1,10 phenanthroline(phen); L represents Schiff base derived from 4,5 diazafluoren 9 one(AFO) and n propylamine) have been prepared and characterized by means of elementary analyses, electronic absorption and IR spectra. The binding of the complexes to calf thymus DNA has been investigated via absorption, emission spectrometry, emission quenching, equilibrium dialysis and circular dichroism spectrometry. The experimental results show that these two complexes bind to calf thymus DNA by electrostatic mode and by non intercalative binding mode respectively.
文摘Some novel polypyridine ligands containing adsorbing groups were synthesized with the purpose of developing new ruthenium(II) polypyridine complexes to be used in solar cell based on dye-sensitized nanocrystilline TiO2 film electrode.
基金supported by the National Key Research and Development Program of China(2021YFB3200700)the National Natural Science Foundation of China(22205172,22175138,52203240 and 22201228)+5 种基金the Young Talent Fund of Association for Science and Technology in Shaanxi(20220604)the China National Postdoctoral Program for Innovative Talents(BX2021231)the Fundamental Research Funds for the Central Universities(xhj032021008-03)the China Postdoctoral Science Foundation(2022M712497,2022M712530)the Shaanxi Province Technological Innovation Guidance Special(2022QFY08-01)the Natural Science Foundation of Shaanxi(2022JQ-129)。
文摘Bacterial infections seriously jeopardize human life and health.Photodynamic therapy(PDT),as an emerging noninvasive antibacterial strategy,has proven to be an effective treatment method against bacterial resistance.However,current photosensitizers suffer from inadequate free radical generation and limited functionality.To address this issue,a newπ-conjugated viologen derivative,3TPhDPyMeOTf,was designed.This derivative with multiple thiophene units enhances visible light absorption,and the presence of multiple pyridine structures allows the photosensitizer to generate more free radicals.Experimental and theoretical studies have demonstrated its inhibitory effect on bacterial growth both in vitro and in vivo,demonstrating a broad-spectrum antibacterial effect.The photosensitizer also exhibits excellent bacterial membrane staining,making it suitable for bacterial imaging.The design of this photosensitizer provides a new direction for the development of potent photosensitizers and photodynamic therapy.
基金supported by the National Natural Science Foundation of China (21676036)the Natural Science Foundation of Chongqing (CSTB2023NSCQ-MSX0580)the Graduate Research and Innovation Foundation of Chongqing (CYB22043 and CYS22073)。
文摘V_(3)O_(7)·H_(2)O(VO)is a high capacity cathode material in the field of aqueous zinc ion batteries(AZIBs),but it is limited by slow ion migration and low electrical conductivity.In this paper,polypyridine(PPyd)intercalated VO with nanoribbon structure was prepared by a simple in-situ pre-intercalation,which is noted VO-PPyd.The total density of states(TDOS)shows that after the pre-intercalation of PPyd,an intermediate energy level appears between the valence band and conduction band,which provides a step that can effectively reduce the band gap and enhance the electron conductivity.Furthermore,the density functional theory(DFT)results found that Zn^(2+)is more easily de-intercalated from the V-O skeleton,which proves that the embeddedness of PPyd improves the diffusion kinetics of Zn^(2+).Electrochemical studies have shown that VO-PPyd cathode materials exhibit excellent rate performance(high specific capacity of 465 and 192 mA h g^(-1)at 0.2 and 10 A g^(-1),respectively)and long-term cycling performance(92.7%capacity retention rate after 5300 cycles),due to their advantages in structure and composition.More importantly,the energy density of VO-PPyd//Zn at 581 and 5806 W kg^(-1)is 375 and 247 W h kg^(-1),respectively.VO-PPyd exhibits excellent electrochemical properties compared to previously reported vanadium based cathodes,which makes it highly competitive in the field of high-performance cathode materials of AZIBs.
基金supported by the National Key R&D Program of China (2016YFB0600901)the Strategic Priority Research Program of the Chinese Academy of Sciences (XDB17030300)~~
文摘Two homogeneous photoelectrocatalytic systems composed of simple polypyridyl Co complexes[Co(tpy)2](PF6)2and[Co(bpy)3](PF6)2as electrocatalysts and a Si wafer as the photoelectrode were used for combined photoelectrochemical reduction of CO2to CO.A high photocurrent density of1.4mA/cm2was observed for the system with the[Co(tpy)2](PF6)2catalyst and a photovoltage of400mV was generated.Faradaic efficiencies of CO were optimized to83%and94%for the[Co(tpy)2](PF6)2and[Co(bpy)3](PF6)2complexes,respectively,in acetonitrile solution with10%methanol(volume fraction,same below)as a protic additive.Addition of2%water volume fraction induced a large amount of non‐specific H2evolution by the Si photoelectrode.
文摘A novel compound, （E）-4′-（4-（but-1-en-3-ynyl）phenyl）-2,2′：6′,2″-terpyridine 1 was synthesized from 4′-（4-bromomethylphenyl）-2,2P：6P,2PP-terpyridine phosphonium salt 2 and propargylaldehyde via Wittig reaction, and characterized by EI-MS and ^1H NMR as well as elemental analysis. The spectral changes of the compound in the presence of transition metal ions, such as Cu（I） or Zn（ID, are investigated.
基金supported by the National Key R&D Program of China(grant nos.2022YFA1502900,2022YFA0911900,and 2021YFA1500800)the National Natural Science Foundation of China(grant nos.22231001,21933007,22193013,and 22088102)+1 种基金the Strategic Priority Research Program of the Chinese Academy of Science(grant no.XDB17000000)the New Cornerstone Science Foundation.
文摘In a carbon dioxide reduction reaction(CO_(2)RR),metal carbonyl intermediate not only serves as the 2e-/2H+reduction product,but it also contributes to CO release for catalyst regeneration.In the past decade,a large number of studies have demonstrated that a catalyst binds,activates,and achieves electron transfer to CO_(2).However,the formation of metal carbonyl intermediate and release of CO during the CO_(2)RR process have not received the same level of attention.Herein,three iron(Ⅱ)complexes are designed to help us to understand the activation of CO_(2)and release of CO.Our research reveals that by removing one of the axial pyridine ligands from polypyridyl-iron(Ⅱ)complex 3,the favorable H2O coordination greatly decreases the activation energy of C-O bond cleavage of complex 1 and 2,and the resultant high-spin Fe(II)carbonyl intermediate with weaker ligand field dramatically reduces CO binding affinity and improves the faradaic efficiency from∼17%to 90%in catalytic CO_(2)RR.
基金supported by the National Natural Science Foundation of China(Grant No.51073048)the National Natural Science Foundation ofHei Long Jiang Province of China(Grant No.B201102)+1 种基金the Science Foundation for Leaders in Academe of Harbin City of China(Grant No.2013RFXXJ024)the Science Foundation for Elitists of Harbin University of Science and Technology
文摘A series of polypyridine ruthenium （II） acetylide complexes, [（tpy）（bpy）RuC≡CC6H4R]^＋ （tpy = 2,2＇：6＇,2＂-terpyridine, bpy = 2,2＇-bipyridine; R = F （1）, C1 （2）, H （3）, Me （4） and OMe （5）） are investigated theoretically to explore their electronic structures and spectroscopic properties. Their ground/excited state geometries, electronic structures and spectroscopic properties are first calculated using density functional theory （DFT） and time-dependent DFT （TDDFT）. The absorption and emission spectra of the complexes in acetonitrile solution are also obtained by using TDDFT （B3LYP） method associated with the CPCM model. The calculations show that the energy levels of HOMOs for 1-5 are sensitive to the substituent on phenylacetylide ligand and increase with the same order of the electron-donating ability of the substituents; however, those of polypyridine-based LUMOs vary slightly. The lowest-energy absorptions and emissions for 1-5 are progressively red-shifted in the order of 1 ~ 2 〈 3 〈 4 〈 5 when the electron-donating groups are introduced into the phenylacetylide [igand. The phosphorescence of 1 are attributed to {[dxz（Ru） ＋π（C≡C）]→[π^＊（tpy）]} （3MLCT/3LLCT） transition, whereas those of 2-5 are originated from { [dxz/dxy（Ru）＋ π（C ≡C）＋g（C6H4R）] → [＊（tpy/bpy）] } （3MLCT/3LLCT） transitions.
