The effects of fluoride ions(F^(-)) on the electrochemical behavior and coordination properties of titanium ions(Ti^(n+)) were studied in this work,by combining electrochemical and mathematical analysis as well as spe...The effects of fluoride ions(F^(-)) on the electrochemical behavior and coordination properties of titanium ions(Ti^(n+)) were studied in this work,by combining electrochemical and mathematical analysis as well as spectral techniques.The α was taken as a factor to indicate the molar concentration ratio of F^(-) and Ti^(n+).Cyclic voltammetry(CV),square wave voltammetry(SWV),and open circuit potential method(OCP)were used to study the electrochemical behavior of titanium ions under conditions of various α,and in-situ sampler was used to prepare molten salt samples when α equal to 0.0,1.0,2.0,3.0,4.0,5.0,6.0,and 8.0.And then,samples were analyzed by X-ray photoelectron spectroscopy(XPS) and Raman spectroscopy.The results showed that F^(-) in molten salt can reduce the reduction steps of titanium ions and greatly affects the proportion of valence titanium ions which making the high-valence titanium content increased and more stable.Ti^(2+) cannot be detected in the molten salt when α is higher than 3.0 and finally transferred to titanium ions with higher valence state.Investigation revealed that the mechanism behind those phenomenon is the coordination compounds(TiCl_(j) F_(i)^(m-)) forming.展开更多
One-photon absorption and two-photon absorption(TPA) properties of three tris(picolyl)amine-based zinc ion sensors are investigated by employing the density functional response theory in combination with the polar...One-photon absorption and two-photon absorption(TPA) properties of three tris(picolyl)amine-based zinc ion sensors are investigated by employing the density functional response theory in combination with the polarizable continuum model.The different isomer and coordination geometry of each probe are taken into account. Special emphasis is placed on the effects of isomerism and the coordination mode on the optical properties. The intra-molecular charge transfer(ICT)properties are specified by natural bond orbital charge analysis. It is shown that the isomerism has non-negligible effects on TPA properties of free ligands. It is found that both the TPA wavelength and the cross section are highly dependent on the coordination mode. When the zinc ion connects with the picolyl unit in the middle of a ligand, the zinc complex has a large TPA intensity in a long wavelength range due to the increased ICT mechanism.展开更多
By incorporating copper sulfate (CuSO4) particles into acrylonitrile butadiene rubber (NBR) followed by heat pressing, a novel vulcanization method is developed in rubber through the formation of coordination cros...By incorporating copper sulfate (CuSO4) particles into acrylonitrile butadiene rubber (NBR) followed by heat pressing, a novel vulcanization method is developed in rubber through the formation of coordination crosslinking. This method totally differs from traditional covalent or non-covalent vulcanization approaches of rubber. No other vulcanizing agent or additional additive is involved in this process. By analyzing the results of DMA, XPS and FT-IR, it is found that the crosslinking of CuSO4 particles filled NBR was induced by in situ coordination between nitrogen atoms of nitrile groups (-CN) and copper ions (Cu^2+) from CuSO4. SEM and EDX results revealed the generation of a core (CuSO4 solid particle)- shell (adherent NBR) structure, which leads to a result that the crosslinked rubber has excellent mechanical properties. Moreover, poly(vinyl chloride) (PVC) and liquid acrylonitrile-butadiene rubber (LNBR) were used as mobilizer to improve the coordination crosslinking of CuSO4/NBR. The addition of PVC or LNBR could lead to higher crosslink density and better mechanical properties of coordination vulcanization. In addition, crystal water in CuSO4 played a positive role to coordination crosslinking of rubber because it decreased the metal point of CuSO4 and promoted the metal ionization.展开更多
Sodium-ion batteries(SIBs)have attracted considerable interest as an alternative to lithium-ion batteries owing to their similar electrochemical performance and superior long-term cycle stability.Organic materials are...Sodium-ion batteries(SIBs)have attracted considerable interest as an alternative to lithium-ion batteries owing to their similar electrochemical performance and superior long-term cycle stability.Organic materials are regarded as promising anode materials for constructing SIBs with high capacity and good retention.However,utilization of organic materials is rather limited by their low energy density and poor stability at high current densities.To overcome these limitations,we utilized a novel polymeric disodium phthalocyanines(pNaPc)as SIB anodes to provide stable coordination sites for Na ions as well as to enhance the stability at high current density.By varying the linker type during a one-pot cyclization and polymerization process,two pNaPc anodes with O-(O-pNaPc)and S-linkers(S-pNaPc)were prepared,and their structural and electrochemical properties were investigated.The O-pNaPc binds Na ions with a lower binding energy compared with S-pNaPc,which leads to more facile Na-ion coordination/dissociation when engaged as SIB anode.The use of O-pNaPc significantly improves the redox kinetics and cycle stability and allows the fabrication of a full cell against Na_(3)V_(2)(PO_(4))_(2)F_(3)/C cathode,which demonstrates its practical application with high energy density(288 Wh kg^(-1))and high power density(149 W kg^(-1)).展开更多
Very recently, the local coordination environment of active sites has been found to strongly influence their performance in electrocatalytic CO_(2) reduction by tuning the intrinsic kinetics of CO_(2) activation and i...Very recently, the local coordination environment of active sites has been found to strongly influence their performance in electrocatalytic CO_(2) reduction by tuning the intrinsic kinetics of CO_(2) activation and intermediate stabilization. It is imperative to elucidate the mechanism for such an influence towards the rational design of efficient catalysts;however, the complex interactions between the multiple factors involved in the system make it challenging to establish a clear structure–performance relationship. In this work, we chose ion-intercalated silver(I)-based coordination networks(AgCNs) with a well-defined structure as a model platform, which enables us to understand the regulation mechanism of counterions as the counterions are the only tuning factor involved in such a system. We prepared two isostructural Ag CNs with different intercalation ions or counterions of BF_(4)^(-) and ClO_(4)^(-)(named as AgCNs-BF_(4) and AgCNs-ClO_(4)) and found that the former has a more competitive CO_(2) electroreduction performance than the latter. AgCNs-BF_(4) achieves the highest Faradaic efficiency for CO_(2) to CO of 87.1% at-1.0 V(vs. RHE) with a higher partial current density, while AgCNs-ClO_(4) exhibits only 77.2% at the same applied potential.Spectroscopic characterizations and theoretical calculation reveal that the presence of BF_(4)^(-)is more favorable for stabilizing the COOH^(*) intermediate by weakening hydrogen bonds, which accounts for the superior activity of Ag CNs-BF_(4).展开更多
One-pot solvothermal reaction of Iransition metal Znn salt with 4,4-bipyddyl (bpy) and 1,4-benzenediacrylic add (H2L) in the presence of Et3N generates a three-dimensional (3-D) supramolecular network with 1-D c...One-pot solvothermal reaction of Iransition metal Znn salt with 4,4-bipyddyl (bpy) and 1,4-benzenediacrylic add (H2L) in the presence of Et3N generates a three-dimensional (3-D) supramolecular network with 1-D cation metal-organic coordination polymer, [Zn(H20)a(bpy)]-L 1, and structurally characterized by single-crystal X-ray diffraction, elemental analyses, IR spectroscopy, and photoluminescent property. The complex crystallizes in triclinic, space group P1 with a = 7.1291(2), b = 7.3784(3), c = 10.5042(3)A, α = 95.049(2), β = 102.162(2), 7 = 97.027(3)0, V= 532.38(3)A3, C22H24N2O8Zn, Mr = 509.82, De= 1.590 g/cm3, p(MoKa)= 1.207 ram-l, F(000) = 264, Z = 1,the finalR=O.0438and wR=O.lOll for 1589 observed reflections (I 〉 2σ(I)). In the crystal structure, the second building unit composed of [Zn(H2O)4].L constructs two distinct 2-D supramolecular sheets and a neutral 3-D architecture. The title compound 1 shows strong photoluminescence with emission maximum at 2 = 455 nm upon λex.max = 355 nm.展开更多
The tinting phenomena of iron oxide contained glasses were studied from aspects of the electronic configuration, the iron ions coordination fields and the ions structure in glass. Several iron ion tinting forms at dif...The tinting phenomena of iron oxide contained glasses were studied from aspects of the electronic configuration, the iron ions coordination fields and the ions structure in glass. Several iron ion tinting forms at different redox or COD (chemical oxygen demand) conditions and their influential factors were given necessary explanations. The results reveal that the Fe^(3+)-O-Fe^(2+) structure is the real tinting reason of iron involved glasses, whereas the Si^(4+)-O-Fe^(3+) and Si^(4+)-O-Fe^(2+) formulations modify the glass colours. Under oxidizing melting condition, the amount of 4/6-coordinated Fe^(3+) increases and makes the glass colour yellowish. Conversely, reducing melting condition makes the 6-coordinated Fe^(2+) increased and gives much blue tint to the glass. The conventional tank furnace melting the very strong reducing condition, which is of high COD glass batch, is not suitable. The high ratio of ferrous/ferric in glass can be obtained with a new refining technology which contains no or little amount of refining agent.展开更多
The properties of one-photon absorption(OPA),emission and two-photon absorption(TPA)of a bipyridine-based zinc ion probe are investigated employing the density functional theory in combination with response functions....The properties of one-photon absorption(OPA),emission and two-photon absorption(TPA)of a bipyridine-based zinc ion probe are investigated employing the density functional theory in combination with response functions.The responsive mechanism and coordination mode effect are explored.The structural fluctuation is illustrated by molecular dynamics simulation.The calculated OPA and emission wavelengths of the probe are consistent with the experimental data.It is found that the red-shift of OPA wavelength and the enhancement of TPA intensity are induced by the increased intra-molecular charge transfer mechanism upon metal binding.The structural fluctuation could result in the blue-shift of TPA wavelength and the decrease of the TPA cross section.The TPA properties are quite different among the zinc complexes with different coordination modes.The TPA wavelength of the complexes with two ligands is close to that of the probe,which is in agreement with the experimental observation.展开更多
By derivatography in insoluble pectins Cu2+ (РCu2+) and Pb2+ (РPb2+), the presence of “a high-temperature component” (150°C- 165°C) is established. During potentiometric alkalimetric titration of ...By derivatography in insoluble pectins Cu2+ (РCu2+) and Pb2+ (РPb2+), the presence of “a high-temperature component” (150°C- 165°C) is established. During potentiometric alkalimetric titration of РCu2+ and РPb2+, endpoints are established at рН accordingly 4.87 and 4.95, proving acid properties of PM. Obtained data show the presence of water in the internal sphere of PM. Considering the loss of this water and the known ratio of metal cations and monomers of pectin (L-), the simplest formulas of pectins are established: [Cu(L-)2(H2O)2], [Pb(L-)2(H2O)4].展开更多
The structure and energy of the carbonium ions formed upon protonation of butane were studied by the DFT methods. Four stable structures are identified for the protonated form of n-butane,the energy increases in the f...The structure and energy of the carbonium ions formed upon protonation of butane were studied by the DFT methods. Four stable structures are identified for the protonated form of n-butane,the energy increases in the following order:C2HC3<C1HC2<C2HH<C1HH,and the stability decreases in the following order C2HC3>C1HC2>C2HH>C1HH. The stability of the penta-coordinated carbonium ions may be explained by the electron distribution in the three-center-two-electron bonds. The delocalization of the penta-coordinated carbonium ion CHC with three-center-two-electron bonds on positive charges was stronger than that of the penta-coordinated carbonium ion CHH with three-center-two-electron bonds and its stability was higher than that of the penta-coordinated carbonium ion CHH with three-center-two-electron bonds.展开更多
Polymerase chain reactions(PCR)are a very important tool for use in cloning,nucleic acid sequencing and diagnostic testing.The storage conditions of PCR reagents are limited to freezing and a lot of mixing steps are n...Polymerase chain reactions(PCR)are a very important tool for use in cloning,nucleic acid sequencing and diagnostic testing.The storage conditions of PCR reagents are limited to freezing and a lot of mixing steps are needed.In this paper,we report using metal ions to form coordination nanomaterials with the intrinsic components of the PCR reagents including dNTP,DNA primers and DNA polymerase as an integrated PCR reaction system.To complete PCR reactions,users need only to dissolve the coordination nanomaterials with a buffer and add template DNA.A few transition metal ions were screened and Cu^(2+)was found to be the most effective metal ion for this purpose.Then the encapsulation efficiency of PCR reagents was measured,which can reach close to 100%for the primers and DNA polymerase,but only 10%for dNTP because dNTP was excess.Further study also exhibited this integrated PCR reaction system can be used for DNA detection with a similar detection limit to the normal PCR,and showed good stability of encapsulated PCR nanomaterial after storage for a week.展开更多
Single crystals of a bismuth-based coordination polymer(CP)with carboxyl-thiol ligands,[Bi(C_(8)H_(2)O_(4)S_(2))(C2H8N)]n(Bi-DSBDC-DMA,DMBDC=2,5-disulfur-1,4-dicarboxylate,DMA=dimethylamine),have been successfully syn...Single crystals of a bismuth-based coordination polymer(CP)with carboxyl-thiol ligands,[Bi(C_(8)H_(2)O_(4)S_(2))(C2H8N)]n(Bi-DSBDC-DMA,DMBDC=2,5-disulfur-1,4-dicarboxylate,DMA=dimethylamine),have been successfully synthesized.X-ray diffraction analysis reveals that Bi-DSBDC-DMA possesses a layered structure,with two-dimensional(2D)Bi-DSBDC networks alternating with layers composed of dimethylamine ions.This material demonstrates semiconducting properties,featuring an optical bandgap of 2.2 eV and an electrical conductivity of 2×10^(-8) S/cm.Furthermore,electrodes based on this material exhibit a capacity of 250 mAh/g after 200 cycles for lithium-ion storage.展开更多
In recent years,intracellular delivery of protein drugs has attracted great attention,and polymer-based systems have been extensively exploited to develop efficient and safe carriers.However,efficient intracellular de...In recent years,intracellular delivery of protein drugs has attracted great attention,and polymer-based systems have been extensively exploited to develop efficient and safe carriers.However,efficient intracellular delivery of protein drugs remains a challenge because of the cell membrane barrier and endosome entrapment.Herein,we report a protein@PP-Zn nanocomplex,which consists of an imidazole-containing block polymer poly(ethylene glycol)-block-poly(β-amino ester)(PEG-b-PAE(Im),PP),zinc ions,and protein drugs,for efficient intracellular protein delivery.PEG-b-PAE(Im)could conjugate proteins via the bridging effect of zinc ions which simultaneously coordinate with imidazole groups on polymer and electron donor groups,such as imidazole and primary amine groups,on protein to improve the loading stability of proteins.Under a slightly acidic environment near cancer cells,the protonation of PAE(Im)backbone increases the positive charge density of the nanocomplex and promotes endocytosis.While under a more acidic environment in endosomes,further protonation of imidazole groups leads to the disintegration of the nanocomplex and the breakdown of endosomes because of the proton sponge effect.Finally,protein is released into the cytoplasm.With the assistance of the nanocomplex,proteins with different sizes and isoelectric points are effectively delivered into cells.This work provides a stable,efficient and universal strategy for intracellular protein delivery.展开更多
Phosphor coated diodes are critical to the lighting industry. Rare-earth doped fluoride phosphors are characterized in this work. Spectroscopy and lifetime measurements of CaF2: Dy3+, LaF3: Eu3+ and Tb3+-doped LaF3 an...Phosphor coated diodes are critical to the lighting industry. Rare-earth doped fluoride phosphors are characterized in this work. Spectroscopy and lifetime measurements of CaF2: Dy3+, LaF3: Eu3+ and Tb3+-doped LaF3 and CaF2 crystals were performed by irradiating the samples with 405 and 375 nm diode lasers. Chromaticity diagrams are developed from spectral measurements. Dy3+-doped CaF2 revealed bright white light emission having peaks at 492, 570 and 654 nm. The measured color coordinates are x = 0.322 and y = 0.340 for Dy3+-doped CaF2 and these values are close to those of sunlight and the coordinated color temperature is 6147 K, under 405 m laser excitation. Eu3+-doped LaF3 revealed twenty emission peaks in the visible wavelength region. The color coordinates measured for LaF3: Eu3+ are x = 0.283 and y = 0.293 under 405 nm diode laser excitation and the color temperature is 9557 K. Eu3+-doped LaF3 provides cool white-light, under 405 nm diode laser excitation. Tb3+-doped fluoride crystals revealed bright white light under low power diode laser excitation. The measured color coordinates for Tb3+-doped CaF2 are x = 0.329 and y = 0.558 and the color temperature is 7713 K. The color coordinates for LaF3: Tb3+ are x = 0.342 and y = 0.365 and the coordinated color temperature is 5370 K. These values are close to those of sunlight.展开更多
This paper proved that octodecyl propylenediamine could form vesicles in pure water and aqueous solution of CuCl2 or Cu(NO3)2. The structure and morphology of vesicles were different when the copper (Ⅱ) salt was ...This paper proved that octodecyl propylenediamine could form vesicles in pure water and aqueous solution of CuCl2 or Cu(NO3)2. The structure and morphology of vesicles were different when the copper (Ⅱ) salt was added to the solution. The results showed that both the counterions and the ligands had strong influence on the configuration of coordinated structures and packing model in bilayer membrane of vesicles.展开更多
基金financially supported by the National Natural Science Foundation of China(No.51804277)the State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization,China(No.CNMRCUKF2008)+1 种基金the State Key Laboratory of Special Rare Metal Materials,China(No.SKL2020K004)the Northwest Rare Metal Materials Research Institute,China。
文摘The effects of fluoride ions(F^(-)) on the electrochemical behavior and coordination properties of titanium ions(Ti^(n+)) were studied in this work,by combining electrochemical and mathematical analysis as well as spectral techniques.The α was taken as a factor to indicate the molar concentration ratio of F^(-) and Ti^(n+).Cyclic voltammetry(CV),square wave voltammetry(SWV),and open circuit potential method(OCP)were used to study the electrochemical behavior of titanium ions under conditions of various α,and in-situ sampler was used to prepare molten salt samples when α equal to 0.0,1.0,2.0,3.0,4.0,5.0,6.0,and 8.0.And then,samples were analyzed by X-ray photoelectron spectroscopy(XPS) and Raman spectroscopy.The results showed that F^(-) in molten salt can reduce the reduction steps of titanium ions and greatly affects the proportion of valence titanium ions which making the high-valence titanium content increased and more stable.Ti^(2+) cannot be detected in the molten salt when α is higher than 3.0 and finally transferred to titanium ions with higher valence state.Investigation revealed that the mechanism behind those phenomenon is the coordination compounds(TiCl_(j) F_(i)^(m-)) forming.
基金Project supported by the Natural Science Foundation of Shandong Province,China(Grant No.ZR2014AM026)the Taishan Scholar Project of Shandong Province,China
文摘One-photon absorption and two-photon absorption(TPA) properties of three tris(picolyl)amine-based zinc ion sensors are investigated by employing the density functional response theory in combination with the polarizable continuum model.The different isomer and coordination geometry of each probe are taken into account. Special emphasis is placed on the effects of isomerism and the coordination mode on the optical properties. The intra-molecular charge transfer(ICT)properties are specified by natural bond orbital charge analysis. It is shown that the isomerism has non-negligible effects on TPA properties of free ligands. It is found that both the TPA wavelength and the cross section are highly dependent on the coordination mode. When the zinc ion connects with the picolyl unit in the middle of a ligand, the zinc complex has a large TPA intensity in a long wavelength range due to the increased ICT mechanism.
基金This work was financially supported by the Program of National Natural Science Foundation of China(No.50473031).
文摘By incorporating copper sulfate (CuSO4) particles into acrylonitrile butadiene rubber (NBR) followed by heat pressing, a novel vulcanization method is developed in rubber through the formation of coordination crosslinking. This method totally differs from traditional covalent or non-covalent vulcanization approaches of rubber. No other vulcanizing agent or additional additive is involved in this process. By analyzing the results of DMA, XPS and FT-IR, it is found that the crosslinking of CuSO4 particles filled NBR was induced by in situ coordination between nitrogen atoms of nitrile groups (-CN) and copper ions (Cu^2+) from CuSO4. SEM and EDX results revealed the generation of a core (CuSO4 solid particle)- shell (adherent NBR) structure, which leads to a result that the crosslinked rubber has excellent mechanical properties. Moreover, poly(vinyl chloride) (PVC) and liquid acrylonitrile-butadiene rubber (LNBR) were used as mobilizer to improve the coordination crosslinking of CuSO4/NBR. The addition of PVC or LNBR could lead to higher crosslink density and better mechanical properties of coordination vulcanization. In addition, crystal water in CuSO4 played a positive role to coordination crosslinking of rubber because it decreased the metal point of CuSO4 and promoted the metal ionization.
基金financial supports from the Research Grants Council of the Hong Kong Special Administrative Region(Poly U15217521)the Hong Kong Polytechnic University(Q-CDA3)Initiative for fostering University of Research and Innovation Program of the National Research Foundation(NRF)funded by the Korean government(MSIT)(No.2020M3H1A1077095)
文摘Sodium-ion batteries(SIBs)have attracted considerable interest as an alternative to lithium-ion batteries owing to their similar electrochemical performance and superior long-term cycle stability.Organic materials are regarded as promising anode materials for constructing SIBs with high capacity and good retention.However,utilization of organic materials is rather limited by their low energy density and poor stability at high current densities.To overcome these limitations,we utilized a novel polymeric disodium phthalocyanines(pNaPc)as SIB anodes to provide stable coordination sites for Na ions as well as to enhance the stability at high current density.By varying the linker type during a one-pot cyclization and polymerization process,two pNaPc anodes with O-(O-pNaPc)and S-linkers(S-pNaPc)were prepared,and their structural and electrochemical properties were investigated.The O-pNaPc binds Na ions with a lower binding energy compared with S-pNaPc,which leads to more facile Na-ion coordination/dissociation when engaged as SIB anode.The use of O-pNaPc significantly improves the redox kinetics and cycle stability and allows the fabrication of a full cell against Na_(3)V_(2)(PO_(4))_(2)F_(3)/C cathode,which demonstrates its practical application with high energy density(288 Wh kg^(-1))and high power density(149 W kg^(-1)).
基金supported by financial support in part by NSFC (91961106, 51902253, 21725102)Anhui Provincial Natural Science Foundation (Grant 2108085MB46)+1 种基金Key Project of Youth Elite Support Plan in Universities of Anhui Province (Grant gxyqZD2021121)Shaanxi Provincial Natural Science Foundation (2020JQ-778)。
文摘Very recently, the local coordination environment of active sites has been found to strongly influence their performance in electrocatalytic CO_(2) reduction by tuning the intrinsic kinetics of CO_(2) activation and intermediate stabilization. It is imperative to elucidate the mechanism for such an influence towards the rational design of efficient catalysts;however, the complex interactions between the multiple factors involved in the system make it challenging to establish a clear structure–performance relationship. In this work, we chose ion-intercalated silver(I)-based coordination networks(AgCNs) with a well-defined structure as a model platform, which enables us to understand the regulation mechanism of counterions as the counterions are the only tuning factor involved in such a system. We prepared two isostructural Ag CNs with different intercalation ions or counterions of BF_(4)^(-) and ClO_(4)^(-)(named as AgCNs-BF_(4) and AgCNs-ClO_(4)) and found that the former has a more competitive CO_(2) electroreduction performance than the latter. AgCNs-BF_(4) achieves the highest Faradaic efficiency for CO_(2) to CO of 87.1% at-1.0 V(vs. RHE) with a higher partial current density, while AgCNs-ClO_(4) exhibits only 77.2% at the same applied potential.Spectroscopic characterizations and theoretical calculation reveal that the presence of BF_(4)^(-)is more favorable for stabilizing the COOH^(*) intermediate by weakening hydrogen bonds, which accounts for the superior activity of Ag CNs-BF_(4).
基金supported by the NNSFC (No. 20701041)the Key Project of Chinese Ministry of Education (No. 208116)+1 种基金the Natural Science Foundation of CQ CSTC (No. 2007BB5228)the Scientific and Technological Project of CQEC (No. KJ080829)
文摘One-pot solvothermal reaction of Iransition metal Znn salt with 4,4-bipyddyl (bpy) and 1,4-benzenediacrylic add (H2L) in the presence of Et3N generates a three-dimensional (3-D) supramolecular network with 1-D cation metal-organic coordination polymer, [Zn(H20)a(bpy)]-L 1, and structurally characterized by single-crystal X-ray diffraction, elemental analyses, IR spectroscopy, and photoluminescent property. The complex crystallizes in triclinic, space group P1 with a = 7.1291(2), b = 7.3784(3), c = 10.5042(3)A, α = 95.049(2), β = 102.162(2), 7 = 97.027(3)0, V= 532.38(3)A3, C22H24N2O8Zn, Mr = 509.82, De= 1.590 g/cm3, p(MoKa)= 1.207 ram-l, F(000) = 264, Z = 1,the finalR=O.0438and wR=O.lOll for 1589 observed reflections (I 〉 2σ(I)). In the crystal structure, the second building unit composed of [Zn(H2O)4].L constructs two distinct 2-D supramolecular sheets and a neutral 3-D architecture. The title compound 1 shows strong photoluminescence with emission maximum at 2 = 455 nm upon λex.max = 355 nm.
文摘The tinting phenomena of iron oxide contained glasses were studied from aspects of the electronic configuration, the iron ions coordination fields and the ions structure in glass. Several iron ion tinting forms at different redox or COD (chemical oxygen demand) conditions and their influential factors were given necessary explanations. The results reveal that the Fe^(3+)-O-Fe^(2+) structure is the real tinting reason of iron involved glasses, whereas the Si^(4+)-O-Fe^(3+) and Si^(4+)-O-Fe^(2+) formulations modify the glass colours. Under oxidizing melting condition, the amount of 4/6-coordinated Fe^(3+) increases and makes the glass colour yellowish. Conversely, reducing melting condition makes the 6-coordinated Fe^(2+) increased and gives much blue tint to the glass. The conventional tank furnace melting the very strong reducing condition, which is of high COD glass batch, is not suitable. The high ratio of ferrous/ferric in glass can be obtained with a new refining technology which contains no or little amount of refining agent.
基金the Natural Science Foundation of Shandong Province,China(Grant No.ZR2014AM026).
文摘The properties of one-photon absorption(OPA),emission and two-photon absorption(TPA)of a bipyridine-based zinc ion probe are investigated employing the density functional theory in combination with response functions.The responsive mechanism and coordination mode effect are explored.The structural fluctuation is illustrated by molecular dynamics simulation.The calculated OPA and emission wavelengths of the probe are consistent with the experimental data.It is found that the red-shift of OPA wavelength and the enhancement of TPA intensity are induced by the increased intra-molecular charge transfer mechanism upon metal binding.The structural fluctuation could result in the blue-shift of TPA wavelength and the decrease of the TPA cross section.The TPA properties are quite different among the zinc complexes with different coordination modes.The TPA wavelength of the complexes with two ligands is close to that of the probe,which is in agreement with the experimental observation.
文摘By derivatography in insoluble pectins Cu2+ (РCu2+) and Pb2+ (РPb2+), the presence of “a high-temperature component” (150°C- 165°C) is established. During potentiometric alkalimetric titration of РCu2+ and РPb2+, endpoints are established at рН accordingly 4.87 and 4.95, proving acid properties of PM. Obtained data show the presence of water in the internal sphere of PM. Considering the loss of this water and the known ratio of metal cations and monomers of pectin (L-), the simplest formulas of pectins are established: [Cu(L-)2(H2O)2], [Pb(L-)2(H2O)4].
文摘The structure and energy of the carbonium ions formed upon protonation of butane were studied by the DFT methods. Four stable structures are identified for the protonated form of n-butane,the energy increases in the following order:C2HC3<C1HC2<C2HH<C1HH,and the stability decreases in the following order C2HC3>C1HC2>C2HH>C1HH. The stability of the penta-coordinated carbonium ions may be explained by the electron distribution in the three-center-two-electron bonds. The delocalization of the penta-coordinated carbonium ion CHC with three-center-two-electron bonds on positive charges was stronger than that of the penta-coordinated carbonium ion CHH with three-center-two-electron bonds and its stability was higher than that of the penta-coordinated carbonium ion CHH with three-center-two-electron bonds.
基金the Natural Sciences and Engineering Research Council of Canada(NSERC)the National Natural Science Foundation of China(Nos.31901776 and 32072181)+1 种基金Agricultural Science and Technology Innovation Program(No.CAAS-ASTIP-2021-IFST-SN2021-05)received a China Scholarship Council(CSC)Scholarship to visit the University of Waterloo。
文摘Polymerase chain reactions(PCR)are a very important tool for use in cloning,nucleic acid sequencing and diagnostic testing.The storage conditions of PCR reagents are limited to freezing and a lot of mixing steps are needed.In this paper,we report using metal ions to form coordination nanomaterials with the intrinsic components of the PCR reagents including dNTP,DNA primers and DNA polymerase as an integrated PCR reaction system.To complete PCR reactions,users need only to dissolve the coordination nanomaterials with a buffer and add template DNA.A few transition metal ions were screened and Cu^(2+)was found to be the most effective metal ion for this purpose.Then the encapsulation efficiency of PCR reagents was measured,which can reach close to 100%for the primers and DNA polymerase,but only 10%for dNTP because dNTP was excess.Further study also exhibited this integrated PCR reaction system can be used for DNA detection with a similar detection limit to the normal PCR,and showed good stability of encapsulated PCR nanomaterial after storage for a week.
基金supported by the Research Projects of Department of Education of Guangdong Province(No.2023KTSCX319)the National Natural Science Foundation of China(No.92372114).
文摘Single crystals of a bismuth-based coordination polymer(CP)with carboxyl-thiol ligands,[Bi(C_(8)H_(2)O_(4)S_(2))(C2H8N)]n(Bi-DSBDC-DMA,DMBDC=2,5-disulfur-1,4-dicarboxylate,DMA=dimethylamine),have been successfully synthesized.X-ray diffraction analysis reveals that Bi-DSBDC-DMA possesses a layered structure,with two-dimensional(2D)Bi-DSBDC networks alternating with layers composed of dimethylamine ions.This material demonstrates semiconducting properties,featuring an optical bandgap of 2.2 eV and an electrical conductivity of 2×10^(-8) S/cm.Furthermore,electrodes based on this material exhibit a capacity of 250 mAh/g after 200 cycles for lithium-ion storage.
基金supported by the National Natural Science Foundation of China(51773099,52203184,22275043,51933006)。
文摘In recent years,intracellular delivery of protein drugs has attracted great attention,and polymer-based systems have been extensively exploited to develop efficient and safe carriers.However,efficient intracellular delivery of protein drugs remains a challenge because of the cell membrane barrier and endosome entrapment.Herein,we report a protein@PP-Zn nanocomplex,which consists of an imidazole-containing block polymer poly(ethylene glycol)-block-poly(β-amino ester)(PEG-b-PAE(Im),PP),zinc ions,and protein drugs,for efficient intracellular protein delivery.PEG-b-PAE(Im)could conjugate proteins via the bridging effect of zinc ions which simultaneously coordinate with imidazole groups on polymer and electron donor groups,such as imidazole and primary amine groups,on protein to improve the loading stability of proteins.Under a slightly acidic environment near cancer cells,the protonation of PAE(Im)backbone increases the positive charge density of the nanocomplex and promotes endocytosis.While under a more acidic environment in endosomes,further protonation of imidazole groups leads to the disintegration of the nanocomplex and the breakdown of endosomes because of the proton sponge effect.Finally,protein is released into the cytoplasm.With the assistance of the nanocomplex,proteins with different sizes and isoelectric points are effectively delivered into cells.This work provides a stable,efficient and universal strategy for intracellular protein delivery.
文摘Phosphor coated diodes are critical to the lighting industry. Rare-earth doped fluoride phosphors are characterized in this work. Spectroscopy and lifetime measurements of CaF2: Dy3+, LaF3: Eu3+ and Tb3+-doped LaF3 and CaF2 crystals were performed by irradiating the samples with 405 and 375 nm diode lasers. Chromaticity diagrams are developed from spectral measurements. Dy3+-doped CaF2 revealed bright white light emission having peaks at 492, 570 and 654 nm. The measured color coordinates are x = 0.322 and y = 0.340 for Dy3+-doped CaF2 and these values are close to those of sunlight and the coordinated color temperature is 6147 K, under 405 m laser excitation. Eu3+-doped LaF3 revealed twenty emission peaks in the visible wavelength region. The color coordinates measured for LaF3: Eu3+ are x = 0.283 and y = 0.293 under 405 nm diode laser excitation and the color temperature is 9557 K. Eu3+-doped LaF3 provides cool white-light, under 405 nm diode laser excitation. Tb3+-doped fluoride crystals revealed bright white light under low power diode laser excitation. The measured color coordinates for Tb3+-doped CaF2 are x = 0.329 and y = 0.558 and the color temperature is 7713 K. The color coordinates for LaF3: Tb3+ are x = 0.342 and y = 0.365 and the coordinated color temperature is 5370 K. These values are close to those of sunlight.
文摘This paper proved that octodecyl propylenediamine could form vesicles in pure water and aqueous solution of CuCl2 or Cu(NO3)2. The structure and morphology of vesicles were different when the copper (Ⅱ) salt was added to the solution. The results showed that both the counterions and the ligands had strong influence on the configuration of coordinated structures and packing model in bilayer membrane of vesicles.