Login In
2018 Volume 34 Issue 5
Research Progress on Carbon Nanotubes in Noble-Metal-Free Electrocatalytic Oxygen Reduction Reaction
2018, 34(5): 807-822
doi: 10.11862/CJIC.2018.101
Abstract:
Fuel cell and metal-air batteries are green batteries which directly convert chemical energy into electricity, possessing important merits compared to the traditional energy, examples of high energy density, safety and environmental benignity. However, the low reserves, high cost, easy poisoning and deactivation of precious metal platinum (Pt) used in cathodic oxygen reduction reactions (ORR) have severely limited the development of the fuel cell in large-scale. Therefore, the research on development of cheap, efficient and stable non-precious metal catalyst has become a hotspot. Carbon nanotubes (CNTs), owning to the outstanding feature such as the intrisic sp2 hybrid structure, excellent conductivity, high specific surface area, good chemical stability, etc, have received wide attentions. Firstly, the recent progress in the noble-metal-free CNTs-based ORR catalysts were summarized, mainly including non-metal element doping, transition metal-nitrogen-CNTs, CNTs supported transition metals and their derivations (oxides, carbides, nitrides, sulfides, etc), CNTs supported single atoms, composited with other carbon materials (graphene, porous carbon, carbon nanofibers) and self-standing electrodes based on CNTs. Finally, the prospect and the future research direction of CNTs-based ORR catalysts are also discussed.
Fuel cell and metal-air batteries are green batteries which directly convert chemical energy into electricity, possessing important merits compared to the traditional energy, examples of high energy density, safety and environmental benignity. However, the low reserves, high cost, easy poisoning and deactivation of precious metal platinum (Pt) used in cathodic oxygen reduction reactions (ORR) have severely limited the development of the fuel cell in large-scale. Therefore, the research on development of cheap, efficient and stable non-precious metal catalyst has become a hotspot. Carbon nanotubes (CNTs), owning to the outstanding feature such as the intrisic sp2 hybrid structure, excellent conductivity, high specific surface area, good chemical stability, etc, have received wide attentions. Firstly, the recent progress in the noble-metal-free CNTs-based ORR catalysts were summarized, mainly including non-metal element doping, transition metal-nitrogen-CNTs, CNTs supported transition metals and their derivations (oxides, carbides, nitrides, sulfides, etc), CNTs supported single atoms, composited with other carbon materials (graphene, porous carbon, carbon nanofibers) and self-standing electrodes based on CNTs. Finally, the prospect and the future research direction of CNTs-based ORR catalysts are also discussed.
2018, 34(5): 823-833
doi: 10.11862/CJIC.2018.119
Abstract:
The magnesium/cobalt ternary oxide, porous MgCo2O4 nanostructures were synthesized by thermal decomposition of crystalline bimetallic coordination polymer precursors. As a result, various hydrothermal reaction time results in isostructural precursors with different crystallinity. When the pyrolysis temperature and binder are chose to be 500℃ and PTFE respectively, the superior practical capacitance with good energy delivery efficiency (η) is obtained. The corresponding MgCo2O4 electrode with high surface area and moderate crystallinity achieves a largest specific capacitance of 348 F·g-1, maximum η value (92.9%) and 93.7% of capacitance retention after 1 000 continuous charge-discharge cycles.
The magnesium/cobalt ternary oxide, porous MgCo2O4 nanostructures were synthesized by thermal decomposition of crystalline bimetallic coordination polymer precursors. As a result, various hydrothermal reaction time results in isostructural precursors with different crystallinity. When the pyrolysis temperature and binder are chose to be 500℃ and PTFE respectively, the superior practical capacitance with good energy delivery efficiency (η) is obtained. The corresponding MgCo2O4 electrode with high surface area and moderate crystallinity achieves a largest specific capacitance of 348 F·g-1, maximum η value (92.9%) and 93.7% of capacitance retention after 1 000 continuous charge-discharge cycles.
2018, 34(5): 834-842
doi: 10.11862/CJIC.2018.092
Abstract:
Fe-CeO2 nanopowders with different dopant contents and N-10% Fe-CeO2 (nFe/(nFe+nCe)=10%) nanopowders using different N-including original materials were synthesized by solvothermal method. The morphology and structure of the nanopowders were analyzed by TEM, XRD, XPS, Raman and UV-Vis spectrometer. The photocatalytic activity was investigated by degrading methylene blue (MB) solution. The results show that the photocatalytic property of CeO2 can be improved by Fe doping. The photocatalytic efficiency reaches the highest for 10% Fe-CeO2, which improve the degradation rate of pure CeO2 from 67% to 95%. N doping can adjust the photocatalytic property of 10% Fe-CeO2. Using concentrated ammonia as N-including original material, the degradation rate of NH3·H2O-N-10% Fe-CeO2 can be further increased to 97%. Moreover, NH3·H2O-N-10% Fe-CeO2 catalyst has excellent performance stability. The photocatalystic degradation rate of MB still remains 89% when the catalyst undergoes 5 recycles usage. The enhanced photocatalytic efficiency can be attributed to the changes of the phase structure and energy band of CeO2 by doping Fe and N, which contribute the production of electrons and holes and their catalystic reaction.
Fe-CeO2 nanopowders with different dopant contents and N-10% Fe-CeO2 (nFe/(nFe+nCe)=10%) nanopowders using different N-including original materials were synthesized by solvothermal method. The morphology and structure of the nanopowders were analyzed by TEM, XRD, XPS, Raman and UV-Vis spectrometer. The photocatalytic activity was investigated by degrading methylene blue (MB) solution. The results show that the photocatalytic property of CeO2 can be improved by Fe doping. The photocatalytic efficiency reaches the highest for 10% Fe-CeO2, which improve the degradation rate of pure CeO2 from 67% to 95%. N doping can adjust the photocatalytic property of 10% Fe-CeO2. Using concentrated ammonia as N-including original material, the degradation rate of NH3·H2O-N-10% Fe-CeO2 can be further increased to 97%. Moreover, NH3·H2O-N-10% Fe-CeO2 catalyst has excellent performance stability. The photocatalystic degradation rate of MB still remains 89% when the catalyst undergoes 5 recycles usage. The enhanced photocatalytic efficiency can be attributed to the changes of the phase structure and energy band of CeO2 by doping Fe and N, which contribute the production of electrons and holes and their catalystic reaction.
2018, 34(5): 843-849
doi: 10.11862/CJIC.2018.121
Abstract:
Different amounts of Y3+ ions have been incorporated into the secondary building units (SBUs) of UiO-67 frameworks during solvothermal crystallization. The SBUs containing integral Zr(Ⅳ)-O and Y(Ⅲ)-O clusters are formed in this bimetallic Y/Zr-UiO-67. Mesoporous yttria doped zirconia is synthesized by two-step calcination treatment using the bimetallic MOFs as a template. This kind of MOFs derived solid solutions has a high BET surface and enhanced oxygen ion conductivity.
Different amounts of Y3+ ions have been incorporated into the secondary building units (SBUs) of UiO-67 frameworks during solvothermal crystallization. The SBUs containing integral Zr(Ⅳ)-O and Y(Ⅲ)-O clusters are formed in this bimetallic Y/Zr-UiO-67. Mesoporous yttria doped zirconia is synthesized by two-step calcination treatment using the bimetallic MOFs as a template. This kind of MOFs derived solid solutions has a high BET surface and enhanced oxygen ion conductivity.
Preparation by Employing Mixed Lithium Source and Carbon Content Optimization of LiFePO4/C Materials
2018, 34(5): 850-856
doi: 10.11862/CJIC.2018.118
Abstract:
The LiFePO4/C composites have been successfully synthesized by adopted Li2CO3 and LiOH·H2O as mixed lithium source, the carbon content of the as-prepared LiFePO4/C materials have been optimized. Since the melting point of LiOH is lower than that of Li2CO3, adopt mixed lithium source can achieve better melting state at the same temperature, and favors the conductivity of lithium ions during the high temperature synthetic process to obtain pure LiFePO4 structure. The carbon content of LiFePO4/C composites were optimized to improve the electroconductivity and control the particle size. The LiFePO4/C cathode displayed excellent crystal structure, processability and electrochemical performances. The discharge capacity of the as-obtained LiFePO4/C composites is as high as 158.2 mAh·g-1, after 100 days storage, the capacity retention of full cells is still maintained higher than 94.0%, representing the superior long-term reliability of the optimized LiFePO4/C material.
The LiFePO4/C composites have been successfully synthesized by adopted Li2CO3 and LiOH·H2O as mixed lithium source, the carbon content of the as-prepared LiFePO4/C materials have been optimized. Since the melting point of LiOH is lower than that of Li2CO3, adopt mixed lithium source can achieve better melting state at the same temperature, and favors the conductivity of lithium ions during the high temperature synthetic process to obtain pure LiFePO4 structure. The carbon content of LiFePO4/C composites were optimized to improve the electroconductivity and control the particle size. The LiFePO4/C cathode displayed excellent crystal structure, processability and electrochemical performances. The discharge capacity of the as-obtained LiFePO4/C composites is as high as 158.2 mAh·g-1, after 100 days storage, the capacity retention of full cells is still maintained higher than 94.0%, representing the superior long-term reliability of the optimized LiFePO4/C material.
2018, 34(5): 857-863
doi: 10.11862/CJIC.2018.116
Abstract:
Series of Dy3+, Eu3+ co-doped LiGd(MoO4)2 phosphors were prepared via sol-gel method, the samples were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and fluorescence spectrometer. The results show that the scheelite structured LiGd (MoO4)2:Dy3+, Eu3+ fluorescent powder is irregular and the particle diameter is 1.8 μm. Photoluminescence spectra show that the phosphors exhibit yellow and blue emission of Dy3+ and red emission of Eu3+ upon 354 nm near ultraviolet light excitation. The critical distance of Dy3+ and Eu3+ is calculated to be 1.383 nm. The mechanism of energy transfer from Dy3+ to Eu3+ is dipole-quadrupole interaction. By adjusting the concentration of Dy3+ and Eu3+, the phosphor can realize the warm-white-light emitting. Moreover, the relationship between the value of correlated color temperature and the rare earth ions (Dy3+, Eu3+) doped concentration was studied in detail.
Series of Dy3+, Eu3+ co-doped LiGd(MoO4)2 phosphors were prepared via sol-gel method, the samples were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and fluorescence spectrometer. The results show that the scheelite structured LiGd (MoO4)2:Dy3+, Eu3+ fluorescent powder is irregular and the particle diameter is 1.8 μm. Photoluminescence spectra show that the phosphors exhibit yellow and blue emission of Dy3+ and red emission of Eu3+ upon 354 nm near ultraviolet light excitation. The critical distance of Dy3+ and Eu3+ is calculated to be 1.383 nm. The mechanism of energy transfer from Dy3+ to Eu3+ is dipole-quadrupole interaction. By adjusting the concentration of Dy3+ and Eu3+, the phosphor can realize the warm-white-light emitting. Moreover, the relationship between the value of correlated color temperature and the rare earth ions (Dy3+, Eu3+) doped concentration was studied in detail.
2018, 34(5): 864-873
doi: 10.11862/CJIC.2018.109
Abstract:
Three asymmetric alkynyl-bridged pentaphenyl substituted biferrocenyl derivatives Fc'-C≡C-Fc (1), Fc'-C≡C-C≡C-Fc (2) and Fc'-C≡C-C≡C-Fc' (3) (Fc'=pentaphenylferrocenyl, Fc=ferrocenyl) were successfully synthesized by eight successive reaction steps using tetraphenylcyclopentadienone as starting material. In the process gaining compounds 1~3, three intermediate products Fc'-COCH3 (5), Fc'-CCl=CHCHO (6) and Fc'-C≡CH (7) were also obtained by three-step continuous reaction using known compound Fc'H (4) prepared by four-step reaction. The crystal structures of compounds 1, 2 and 5, 7 were determined by X-ray single crystal diffraction technique, and the electrochemical properties of compounds 1~7 were studied by cyclic voltammetry. The results show the C-H…π interactions and the steric hindrance result in the different space orientations of Fc' and Fc units in the crystals of 1 and 2. The redox potential of the iron center is increased (Epa(Fc'-H)=0.658 V, Epa (Fc-H)=0.511 V) while five phenyls are introduced into a five-membered ring of ferrocenyl unit. Comparing with known compounds Fc-C≡C-Fc and Fc-C≡C-C≡C-Fc (ΔEFc-C≡C-Fc=0.215 V, ΔEFc-C≡C-C≡C-Fc=0.134 V), the oxidation potential differences (ΔE) of 1~3 are all elevated (ΔE1=0.236 V; ΔE2=0.170 V; ΔE3=0.146 V). In comparison with 1 and Fc-C≡C-Fc, with 2 and Fc-C≡C-C≡C-Fc and 3, we discover the ΔE values of corresponding compounds were significantly enhanced while two different groups Fc' and Fc are bridged into alkynyl linkage.
Three asymmetric alkynyl-bridged pentaphenyl substituted biferrocenyl derivatives Fc'-C≡C-Fc (1), Fc'-C≡C-C≡C-Fc (2) and Fc'-C≡C-C≡C-Fc' (3) (Fc'=pentaphenylferrocenyl, Fc=ferrocenyl) were successfully synthesized by eight successive reaction steps using tetraphenylcyclopentadienone as starting material. In the process gaining compounds 1~3, three intermediate products Fc'-COCH3 (5), Fc'-CCl=CHCHO (6) and Fc'-C≡CH (7) were also obtained by three-step continuous reaction using known compound Fc'H (4) prepared by four-step reaction. The crystal structures of compounds 1, 2 and 5, 7 were determined by X-ray single crystal diffraction technique, and the electrochemical properties of compounds 1~7 were studied by cyclic voltammetry. The results show the C-H…π interactions and the steric hindrance result in the different space orientations of Fc' and Fc units in the crystals of 1 and 2. The redox potential of the iron center is increased (Epa(Fc'-H)=0.658 V, Epa (Fc-H)=0.511 V) while five phenyls are introduced into a five-membered ring of ferrocenyl unit. Comparing with known compounds Fc-C≡C-Fc and Fc-C≡C-C≡C-Fc (ΔEFc-C≡C-Fc=0.215 V, ΔEFc-C≡C-C≡C-Fc=0.134 V), the oxidation potential differences (ΔE) of 1~3 are all elevated (ΔE1=0.236 V; ΔE2=0.170 V; ΔE3=0.146 V). In comparison with 1 and Fc-C≡C-Fc, with 2 and Fc-C≡C-C≡C-Fc and 3, we discover the ΔE values of corresponding compounds were significantly enhanced while two different groups Fc' and Fc are bridged into alkynyl linkage.
2018, 34(5): 874-882
doi: 10.11862/CJIC.2018.120
Abstract:
The interaction between rutile TiO2 nanoparticle clusters (NPCs) and aquouranyl species have been examined using a relativistic functional theory (DFT). Effects of NPCs with various layers (1~4) and different surface areas on structural parameters of uranium adsorption complexes as well as adsorption interaction energies were investigated. It is found that the two-layered (2L) NPC (labeled as 2L-Ti15) with a surface area of 1.1 nm×0.6 nm and containing 63 atoms can reasonably stand for experimentally real TiO2 nanocrystallite. Moreover, the model is able to save computational resources. Calculations reveal a covalent bonding interaction in the 2L-Ti15-[(UO2)(H2O)3]2+ complex. The direct evidences include that the bond lengths of U-Osurf were optimized to be 0.233~0.238 nm, which fall well within the range of U-O distances of reported uranyl complexes. The process that the NPC adsorbs aquouranyl species is exothermic in the gas phase, releasing energy of -3.02 eV; the consideration of environment media of solution results in a slightly uphill process, requiring 0.16 eV energy. The energetic decomposition indicates that U-Osurf bonds are dominated by orbital interactions, accounting for 94%; other factors show a little effect, although electrostatic attraction is a little larger than Pauli repulsion. Electron density-based QTAIM (quantum theory of atoms in molecule) analyses unravel that the U-Osurf interaction is a dative bond per se, whose strength is stronger than that of U-OH2, but much weaker than that of U=Oyl. Inspection of wavefunction demonstrates that HOMO is contributed by O(2p) of NPC TiO2 mixed with a small amount of σ(U=O) bonding character, while LUMO is U(5f)-based character modified by Ti(3d). The HOMO-LUMO gap was calculated to be 2.40 eV, which much narrower than the one of NPC semiconductor (3.35 eV). From a point of view of absorption spectra, the complex system would present a visible light-harvesting capability.
The interaction between rutile TiO2 nanoparticle clusters (NPCs) and aquouranyl species have been examined using a relativistic functional theory (DFT). Effects of NPCs with various layers (1~4) and different surface areas on structural parameters of uranium adsorption complexes as well as adsorption interaction energies were investigated. It is found that the two-layered (2L) NPC (labeled as 2L-Ti15) with a surface area of 1.1 nm×0.6 nm and containing 63 atoms can reasonably stand for experimentally real TiO2 nanocrystallite. Moreover, the model is able to save computational resources. Calculations reveal a covalent bonding interaction in the 2L-Ti15-[(UO2)(H2O)3]2+ complex. The direct evidences include that the bond lengths of U-Osurf were optimized to be 0.233~0.238 nm, which fall well within the range of U-O distances of reported uranyl complexes. The process that the NPC adsorbs aquouranyl species is exothermic in the gas phase, releasing energy of -3.02 eV; the consideration of environment media of solution results in a slightly uphill process, requiring 0.16 eV energy. The energetic decomposition indicates that U-Osurf bonds are dominated by orbital interactions, accounting for 94%; other factors show a little effect, although electrostatic attraction is a little larger than Pauli repulsion. Electron density-based QTAIM (quantum theory of atoms in molecule) analyses unravel that the U-Osurf interaction is a dative bond per se, whose strength is stronger than that of U-OH2, but much weaker than that of U=Oyl. Inspection of wavefunction demonstrates that HOMO is contributed by O(2p) of NPC TiO2 mixed with a small amount of σ(U=O) bonding character, while LUMO is U(5f)-based character modified by Ti(3d). The HOMO-LUMO gap was calculated to be 2.40 eV, which much narrower than the one of NPC semiconductor (3.35 eV). From a point of view of absorption spectra, the complex system would present a visible light-harvesting capability.
2018, 34(5): 883-888
doi: 10.11862/CJIC.2018.128
Abstract:
(NH4)3[Ru2(hedp)2]·2H2O (hedp=1-hydroxyethylidenediphosphonate) with t-BuOOH as oxidant is proved to be highly effective in the catalytic oxidation of alcohol, such as secondary alcohol and long-chain aliphatic alcohol, in aqueous solution at room temperature. The phase-transfer catalyst is not necessary. The acid or the coordinated base inhibits ketone production, while the base improves the reaction selectivity and the yield. The mechanism is proposed as a peroxometal pathway. The UV-Vis spectra prove that the key intermediates Ru2-OOtBu is formed.
(NH4)3[Ru2(hedp)2]·2H2O (hedp=1-hydroxyethylidenediphosphonate) with t-BuOOH as oxidant is proved to be highly effective in the catalytic oxidation of alcohol, such as secondary alcohol and long-chain aliphatic alcohol, in aqueous solution at room temperature. The phase-transfer catalyst is not necessary. The acid or the coordinated base inhibits ketone production, while the base improves the reaction selectivity and the yield. The mechanism is proposed as a peroxometal pathway. The UV-Vis spectra prove that the key intermediates Ru2-OOtBu is formed.
2018, 34(5): 889-896
doi: 10.11862/CJIC.2018.127
Abstract:
Water-soluble Cu(Ⅱ) phthalocyanine 6 and Ni(Ⅱ) phthalocyanine 7 were successfully synthesized starting from 1, 2-dicynobenzen derivative. The photophysical and photochemical properties of these phthalocyanines show that they are not only very stable towards either heat or light, but also could yield singlet oxygen moderately. In vitro cell study demonstrates that both 6 and 7 could inhibit the growth of cancer cells in dark and also exhibit photodynamic therapy effect upon exposure to red light. These results show that these compounds have synergistic anticancer activities of photodynamic therapy and chemotherapy effects.
Water-soluble Cu(Ⅱ) phthalocyanine 6 and Ni(Ⅱ) phthalocyanine 7 were successfully synthesized starting from 1, 2-dicynobenzen derivative. The photophysical and photochemical properties of these phthalocyanines show that they are not only very stable towards either heat or light, but also could yield singlet oxygen moderately. In vitro cell study demonstrates that both 6 and 7 could inhibit the growth of cancer cells in dark and also exhibit photodynamic therapy effect upon exposure to red light. These results show that these compounds have synergistic anticancer activities of photodynamic therapy and chemotherapy effects.
2018, 34(5): 897-905
doi: 10.11862/CJIC.2018.129
Abstract:
Two new metal-organic complex, [Zn(eiqnthz)2]·DMF (1) and[Zn3(piqnthz)2Cl2]·2H2O (2) (Heiqnthz=N, N'-acetyl isoquinoline hydrazine, H2Piqnthz=N, N'-propionyl isoquinoline hydrazine), has been synthesized by common solution method. The structures and properties of complexes 1 and 2 are determined and characterized by single-crystal X-ray analysis, XRD powder diffraction analysis, infrared spectroscopy, thermal stability analysis and fluorescence analysis method. The crystal structural analysis revealed that the complex 1 crystalizes in monoclinic, space group C2/c, with 4 nitrogen atoms and 2 oxygen atoms from two ligands to forming a N4O2 distorted octahedral coordination geometry around the zinc ions. The complex 2 belongs to monoclinic system, space group C2/c as a three nuclear structure. Zn(1), Zn(2), Zn(3) ions are penta-coordinated, and the whole molecule presents V shape. Zn(1) and Zn(3) are located at both ends of the molecule and deformed tetragonal pyramidal coordination structures. Zn(2) is located in the middle to form a triangular bipyramid coordination structure. The fluorescence spectroscopic analysis demonstrated that Heiqnthz and H2piqnthz have red-shifted phenomenon after coordinated with zinc(Ⅱ) ion.
Two new metal-organic complex, [Zn(eiqnthz)2]·DMF (1) and[Zn3(piqnthz)2Cl2]·2H2O (2) (Heiqnthz=N, N'-acetyl isoquinoline hydrazine, H2Piqnthz=N, N'-propionyl isoquinoline hydrazine), has been synthesized by common solution method. The structures and properties of complexes 1 and 2 are determined and characterized by single-crystal X-ray analysis, XRD powder diffraction analysis, infrared spectroscopy, thermal stability analysis and fluorescence analysis method. The crystal structural analysis revealed that the complex 1 crystalizes in monoclinic, space group C2/c, with 4 nitrogen atoms and 2 oxygen atoms from two ligands to forming a N4O2 distorted octahedral coordination geometry around the zinc ions. The complex 2 belongs to monoclinic system, space group C2/c as a three nuclear structure. Zn(1), Zn(2), Zn(3) ions are penta-coordinated, and the whole molecule presents V shape. Zn(1) and Zn(3) are located at both ends of the molecule and deformed tetragonal pyramidal coordination structures. Zn(2) is located in the middle to form a triangular bipyramid coordination structure. The fluorescence spectroscopic analysis demonstrated that Heiqnthz and H2piqnthz have red-shifted phenomenon after coordinated with zinc(Ⅱ) ion.
2018, 34(5): 906-916
doi: 10.11862/CJIC.2018.110
Abstract:
MOF-Fe samples were prepared with HF, HCl, H2O and NaAc as conditioning agents by hydrothermal method. The characteristics of the samples were studied by X-ray diffraction (XRD), Transmission electron microscope (TEM), N2 adsorption/desorption, thermal analysis (TG/DTG and DTA) and proton potentiometric titration. Isothermal adsorption experiments of selenite (Se(Ⅳ)) on the samples were carried out. Crystal structure of all samples are same as MIL-100(Fe), and the morphology are octahedral, while the crystallinities and crystal orientations are different. The BET surface area are 1 683, 1 517, 1 641 and 1 734 m2·g-1, respectively, and total pore volumes of the samples are decreased orderly. The micropore diameter are 1.27, 1.22, 1.22 and 1.17 nm for MOF-Fe(HF), MOF-Fe(HCl), MOF-Fe(H2O) and MOF-Fe(NaAc). The temperature of decarboxylation of MOF-Fe(HF) is highest (415℃), while its carbonization temperature for benzene ring is lowest (462℃) compared with the others. A weight loss caused by redox between iron oxide and carbon appears in MOF-Fe(HCl), MOF-Fe(H2O) and MOF-Fe(NaAc). The sequence of H+ consumed during the process of proton potentiometric titrations for samples is MOF-Fe(H2O) > MOF-Fe(HCl) > MOF-Fe(HF)=MOF-Fe(NaAc), and pH value of zero point charge (pHZPC) are 3.1, 3.5, 3.6 and 3.5 accordingly. The sequence about the affinity of adsorption for Se(Ⅳ) on samples is MOF-Fe(NaAc) > MOF-Fe(HCl) > MOF-Fe(H2O) > MOF-Fe(HF), and the maximum adsorption capacities (Qm) are 77.69, 107.07, 117.40 and 87.15 mg·g-1 correspondingly. The Qm of Se(Ⅳ) on samples have positive correlation with density of hydroxyl for samples observably. This study reveals that the thermostability and density of active site of MOF-Fe are influenced by the conditioning agent when MOF-Fe was prepared. The HF could increase the strength of C-C between carboxyl and benzene ring, decrease carbonization temperature of benzene ring of MOF-Fe, and improve the thermostability of iron oxides after heating. While HCl and H2O could improve the density of active site in samples, then the Qm of Se(Ⅳ) adsorbed on MOF-Fe could be increased.
MOF-Fe samples were prepared with HF, HCl, H2O and NaAc as conditioning agents by hydrothermal method. The characteristics of the samples were studied by X-ray diffraction (XRD), Transmission electron microscope (TEM), N2 adsorption/desorption, thermal analysis (TG/DTG and DTA) and proton potentiometric titration. Isothermal adsorption experiments of selenite (Se(Ⅳ)) on the samples were carried out. Crystal structure of all samples are same as MIL-100(Fe), and the morphology are octahedral, while the crystallinities and crystal orientations are different. The BET surface area are 1 683, 1 517, 1 641 and 1 734 m2·g-1, respectively, and total pore volumes of the samples are decreased orderly. The micropore diameter are 1.27, 1.22, 1.22 and 1.17 nm for MOF-Fe(HF), MOF-Fe(HCl), MOF-Fe(H2O) and MOF-Fe(NaAc). The temperature of decarboxylation of MOF-Fe(HF) is highest (415℃), while its carbonization temperature for benzene ring is lowest (462℃) compared with the others. A weight loss caused by redox between iron oxide and carbon appears in MOF-Fe(HCl), MOF-Fe(H2O) and MOF-Fe(NaAc). The sequence of H+ consumed during the process of proton potentiometric titrations for samples is MOF-Fe(H2O) > MOF-Fe(HCl) > MOF-Fe(HF)=MOF-Fe(NaAc), and pH value of zero point charge (pHZPC) are 3.1, 3.5, 3.6 and 3.5 accordingly. The sequence about the affinity of adsorption for Se(Ⅳ) on samples is MOF-Fe(NaAc) > MOF-Fe(HCl) > MOF-Fe(H2O) > MOF-Fe(HF), and the maximum adsorption capacities (Qm) are 77.69, 107.07, 117.40 and 87.15 mg·g-1 correspondingly. The Qm of Se(Ⅳ) on samples have positive correlation with density of hydroxyl for samples observably. This study reveals that the thermostability and density of active site of MOF-Fe are influenced by the conditioning agent when MOF-Fe was prepared. The HF could increase the strength of C-C between carboxyl and benzene ring, decrease carbonization temperature of benzene ring of MOF-Fe, and improve the thermostability of iron oxides after heating. While HCl and H2O could improve the density of active site in samples, then the Qm of Se(Ⅳ) adsorbed on MOF-Fe could be increased.
2018, 34(5): 917-924
doi: 10.11862/CJIC.2018.106
Abstract:
Magnesium-doped hydroxyapatites nanoparticles (Mg-HAs) with different feeding molar ratios were synthesized by step precipitation reaction and one pot reaction. The morphology and size of the Mg-HAs were controlled by different feeding molar ratio of magnesium nitrate and calcium nitrate. The Mg-HAs were characterized by transmission electron microscope, X-ray diffraction, et al. MTT method was used to evaluated in vitro cytotoxicity of the Mg-HAs. Results show that the synthesized Mg-HAs had the frame with fiber like structure, high specific surface area and low cell cytotoxicity. Mg-HAs as drug carrier material and cisplatin (cDDP) as a model drug were investigated, and the max loading rate was 54.84%. The drug loading Mg-HAs also have release properties (the releasing rate is 41.72% after 72 h), and a better inhibitory effect on cancer cells.
Magnesium-doped hydroxyapatites nanoparticles (Mg-HAs) with different feeding molar ratios were synthesized by step precipitation reaction and one pot reaction. The morphology and size of the Mg-HAs were controlled by different feeding molar ratio of magnesium nitrate and calcium nitrate. The Mg-HAs were characterized by transmission electron microscope, X-ray diffraction, et al. MTT method was used to evaluated in vitro cytotoxicity of the Mg-HAs. Results show that the synthesized Mg-HAs had the frame with fiber like structure, high specific surface area and low cell cytotoxicity. Mg-HAs as drug carrier material and cisplatin (cDDP) as a model drug were investigated, and the max loading rate was 54.84%. The drug loading Mg-HAs also have release properties (the releasing rate is 41.72% after 72 h), and a better inhibitory effect on cancer cells.
2018, 34(5): 925-932
doi: 10.11862/CJIC.2018.132
Abstract:
Three-dimensional flower-like LDH (3D-MgAl LDH) microspheres were successfully synthesized via hydrothermal method. The sodium dodecylsulfate was used as soft template. The effect of Mg/Al mole ratio, the concentration of SDS and the reaction time on the crystallinity, composition and morphology of 3D-MgAl LDH were investigated by XRD, FT-IR, SEM and TEM. The results show that the optimal condition for uniform 3D-MgAl LDH microspheres with high crystallinity, regular flower-like morphology and thickness uniformity of nanosheets are as follows, nMg/nAl=2, the concentration of SDS was 0.1 mol·L-1, and reaction time of 6 h. In addition, the growth mechanism of 3D-MgAl LDH was also inferred, SDS was used for intercalated anion to form LDH as well as could form micelles that bond to the outside surfaces and plate edges of LDH, which induced LDH nanosheet cross-growth. Finally, the adsorption activity present that 3D-MgAl LDH exhibits great adsorption capacity of ca. 30 mg·g-1 for naphthalene and the removal rate of 100%.
Three-dimensional flower-like LDH (3D-MgAl LDH) microspheres were successfully synthesized via hydrothermal method. The sodium dodecylsulfate was used as soft template. The effect of Mg/Al mole ratio, the concentration of SDS and the reaction time on the crystallinity, composition and morphology of 3D-MgAl LDH were investigated by XRD, FT-IR, SEM and TEM. The results show that the optimal condition for uniform 3D-MgAl LDH microspheres with high crystallinity, regular flower-like morphology and thickness uniformity of nanosheets are as follows, nMg/nAl=2, the concentration of SDS was 0.1 mol·L-1, and reaction time of 6 h. In addition, the growth mechanism of 3D-MgAl LDH was also inferred, SDS was used for intercalated anion to form LDH as well as could form micelles that bond to the outside surfaces and plate edges of LDH, which induced LDH nanosheet cross-growth. Finally, the adsorption activity present that 3D-MgAl LDH exhibits great adsorption capacity of ca. 30 mg·g-1 for naphthalene and the removal rate of 100%.
2018, 34(5): 933-941
doi: 10.11862/CJIC.2018.114
Abstract:
The supported Pt-Al/MCM-41 catalyst was prepared by using mesoporous silica MCM-41 as the carrier and AlCl3 as the accelerator. The structure, morphology of catalyst and intermetallic force were systematically characterized by fourier transform infrared spectroscopy (FTIR), N2 adsorption-desorption, X-ray diffraction assay (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), inductively coupled plasma (ICP). The effects of various amount of Al on the structure of the catalyst and the intermetallic force were discussed, and the catalytic application in hydrosilylation of allyl polyether (PGAE) and heptamethyltrisiloxane (MDHM) was investigated. The results show that the dosage of Al had a certain effect on the structure and ordering degree of the catalyst, and the specific surface area, pore volume and order degree decrease with the increase of Al content. Besides, addition of a certain amount of Al is beneficial to improve the dispersion and decreases size of platinum particle. Pt1Al2/MCM-41 has excellent reusability, which could be reused six times without significant loss of activity and the conversion of MDHM is above 90%, The synergist was synthesized with nPGAE/nMDHM=1.1 in the presence of 0.5% catalyst at 100℃ for 4 h.
The supported Pt-Al/MCM-41 catalyst was prepared by using mesoporous silica MCM-41 as the carrier and AlCl3 as the accelerator. The structure, morphology of catalyst and intermetallic force were systematically characterized by fourier transform infrared spectroscopy (FTIR), N2 adsorption-desorption, X-ray diffraction assay (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), inductively coupled plasma (ICP). The effects of various amount of Al on the structure of the catalyst and the intermetallic force were discussed, and the catalytic application in hydrosilylation of allyl polyether (PGAE) and heptamethyltrisiloxane (MDHM) was investigated. The results show that the dosage of Al had a certain effect on the structure and ordering degree of the catalyst, and the specific surface area, pore volume and order degree decrease with the increase of Al content. Besides, addition of a certain amount of Al is beneficial to improve the dispersion and decreases size of platinum particle. Pt1Al2/MCM-41 has excellent reusability, which could be reused six times without significant loss of activity and the conversion of MDHM is above 90%, The synergist was synthesized with nPGAE/nMDHM=1.1 in the presence of 0.5% catalyst at 100℃ for 4 h.
2018, 34(5): 942-950
doi: 10.11862/CJIC.2018.122
Abstract:
Porous and graphene-type honeycomb-like structured N-doped and Co-Mn incorporated carbon materials derived from Bombyx mori silk cocoons were synthesized via one-step thermal carbonization and graphitization process. Due to the high specific surface area of honeycomb-like structure, the exposed Co-Mn active sites and the pyridine-N and graphitic-N, the prepared 3% Co-Mn/silk cocoon carbon materials (3% Co-Mn/SCC) exhibits good hydrogen evolution reaction (HER) performance with a low onset potential of 121 mV, a low overpotential of 155 mV at 10 mA·cm-2 and a Tafel slope of 130 mV·dec-1 as well as a long-term stability in acidic electrolyte. Meanwhile, the 2% Co-Mn/SCC also shows great oxygen evolution reaction (OER) performance in 1 mol·L-1 KOH with the lowest onset potential 1.5 mV and a Tafel slope of 143 mV·dec-1. This result demonstrates that MCo-Mn/SCC (M is the mass fraction of Co and Mn) possess both HER and OER catalytic activity and can act as a bifunctional catalyst for water electrolysis.
Porous and graphene-type honeycomb-like structured N-doped and Co-Mn incorporated carbon materials derived from Bombyx mori silk cocoons were synthesized via one-step thermal carbonization and graphitization process. Due to the high specific surface area of honeycomb-like structure, the exposed Co-Mn active sites and the pyridine-N and graphitic-N, the prepared 3% Co-Mn/silk cocoon carbon materials (3% Co-Mn/SCC) exhibits good hydrogen evolution reaction (HER) performance with a low onset potential of 121 mV, a low overpotential of 155 mV at 10 mA·cm-2 and a Tafel slope of 130 mV·dec-1 as well as a long-term stability in acidic electrolyte. Meanwhile, the 2% Co-Mn/SCC also shows great oxygen evolution reaction (OER) performance in 1 mol·L-1 KOH with the lowest onset potential 1.5 mV and a Tafel slope of 143 mV·dec-1. This result demonstrates that MCo-Mn/SCC (M is the mass fraction of Co and Mn) possess both HER and OER catalytic activity and can act as a bifunctional catalyst for water electrolysis.
2018, 34(5): 951-956
doi: 10.11862/CJIC.2018.126
Abstract:
Two novel dinuclear Ln(Ⅲ) complexes[Gd2(L)4(HCOO)2(CH3OH)2] (1) and[Dy2(L)4(CH3COO)2(CH3OH)2] (2) (HL=2-hydroxy-3-methoxy-5-bromobenzaldehyde oxime) have been successfully synthesized and characterized by single crystal X-ray diffraction, IR spectroscopy and elemental analyses. Single crystal X-ray crystallographic analyses reveal that these two complexes have similar structures, in which two symmetric nine-coordinate Ln(Ⅲ) ions are bridged by two phenoxide groups from two Schiff base ligands, two formate ions for 1 and two acetate ions for 2 respectively. Magnetic studies reveal that weak antiferromagnetic interaction between Gd(Ⅲ) ions existing in complex 1, while complex 2 shows slow relaxation of magnetization. CCDC: 1570377, 1; 1570378, 2.
Two novel dinuclear Ln(Ⅲ) complexes[Gd2(L)4(HCOO)2(CH3OH)2] (1) and[Dy2(L)4(CH3COO)2(CH3OH)2] (2) (HL=2-hydroxy-3-methoxy-5-bromobenzaldehyde oxime) have been successfully synthesized and characterized by single crystal X-ray diffraction, IR spectroscopy and elemental analyses. Single crystal X-ray crystallographic analyses reveal that these two complexes have similar structures, in which two symmetric nine-coordinate Ln(Ⅲ) ions are bridged by two phenoxide groups from two Schiff base ligands, two formate ions for 1 and two acetate ions for 2 respectively. Magnetic studies reveal that weak antiferromagnetic interaction between Gd(Ⅲ) ions existing in complex 1, while complex 2 shows slow relaxation of magnetization. CCDC: 1570377, 1; 1570378, 2.
2018, 34(5): 957-966
doi: 10.11862/CJIC.2018.105
Abstract:
Two new trinuclear complexes, [Co2ⅢCoⅡL2(μ-OAc)4] (1) and[Ni3L2(μ-OAc)2(CH3OH)2]·2H2O (2), were obtained and fully characterized, where L was the condensation product between 2-hydroxy-1, 3-propane diamine and 5-fluorosalicylaldehyde. The interaction of complex 1 with DNA has been investigated by spectroscopy, viscosity measurements and electrochemical studies. Absorption spectroscopic investigation reveals intercalative binding of Co complex with DNA, with a binding constant of 2.43×105 L·mol-1. Fluorescence spectroscopy shows that complex 1 can displace ethidium bromide and bind to DNA, with a quenching constant of 4.92×103 L·mol-1. The variable-temperature magnetisms of complexes 1 and 2 show that there are antiferromagnetic couplings among the three metal centers in both complexes. CCDC: 1587441, 1; 1587442, 2.
Two new trinuclear complexes, [Co2ⅢCoⅡL2(μ-OAc)4] (1) and[Ni3L2(μ-OAc)2(CH3OH)2]·2H2O (2), were obtained and fully characterized, where L was the condensation product between 2-hydroxy-1, 3-propane diamine and 5-fluorosalicylaldehyde. The interaction of complex 1 with DNA has been investigated by spectroscopy, viscosity measurements and electrochemical studies. Absorption spectroscopic investigation reveals intercalative binding of Co complex with DNA, with a binding constant of 2.43×105 L·mol-1. Fluorescence spectroscopy shows that complex 1 can displace ethidium bromide and bind to DNA, with a quenching constant of 4.92×103 L·mol-1. The variable-temperature magnetisms of complexes 1 and 2 show that there are antiferromagnetic couplings among the three metal centers in both complexes. CCDC: 1587441, 1; 1587442, 2.
2018, 34(5): 967-972
doi: 10.11862/CJIC.2018.115
Abstract:
A new[Dy2Co8] core Complex[Dy2Co8(L)4(HL)4(HCOO)4(OH)2Cl2(CH3OH)2]Cl2·4CH3OH·2H2O (1) (H2L=diethanolamine) was prepared and characterized by single crystal X-ray diffraction, FTIR spectra, elemental and magnetic analysis. It crystallizes in the triclinic system, space group P1. X-ray diffraction analysis reveals that each Dy(Ⅲ) was nine-coordinated and each Co(Ⅱ) ion displays distorted octahedral coordination environment. CCDC: 1576526.
A new[Dy2Co8] core Complex[Dy2Co8(L)4(HL)4(HCOO)4(OH)2Cl2(CH3OH)2]Cl2·4CH3OH·2H2O (1) (H2L=diethanolamine) was prepared and characterized by single crystal X-ray diffraction, FTIR spectra, elemental and magnetic analysis. It crystallizes in the triclinic system, space group P1. X-ray diffraction analysis reveals that each Dy(Ⅲ) was nine-coordinated and each Co(Ⅱ) ion displays distorted octahedral coordination environment. CCDC: 1576526.
2018, 34(5): 973-980
doi: 10.11862/CJIC.2018.107
Abstract:
Two new zinc complexes[Zn(MTC)2(bpp)]n (1) and[Zn(MTC)(phen)(H2O)2](MTC) (2) (HMTC=4-methyl-1, 2, 3-thiadiazol-5-carboxylic, C4H4N2O2S; bpp=1, 3-bis(4-pyridyl) propane; phen=1-10-phenanthroline) have been synthesized and characterized by single crystal X-ray diffraction, elemental analysis, IR spectra, PXRD and TG. The single crystal X-ray diffraction reveals that the complex 1 is two-dimensional network structure and crystallized in monoclinic with space group P21/c. Central Zn2+ is four-coordinated forming a distorted tetrahedron coordina-tion geometry. The complex 2 is two-dimensional layered structure and crystallized in triclinic with space group P1. Central Zn2+ is five-coordinated forming a distorted trigonal bipyramid coordination geometry. In addition, the interaction of complexes and ligand with EB-DNA were also studied by EtBr fluorescence probe. The interaction of complexes with DNA is stronger than ligand.
Two new zinc complexes[Zn(MTC)2(bpp)]n (1) and[Zn(MTC)(phen)(H2O)2](MTC) (2) (HMTC=4-methyl-1, 2, 3-thiadiazol-5-carboxylic, C4H4N2O2S; bpp=1, 3-bis(4-pyridyl) propane; phen=1-10-phenanthroline) have been synthesized and characterized by single crystal X-ray diffraction, elemental analysis, IR spectra, PXRD and TG. The single crystal X-ray diffraction reveals that the complex 1 is two-dimensional network structure and crystallized in monoclinic with space group P21/c. Central Zn2+ is four-coordinated forming a distorted tetrahedron coordina-tion geometry. The complex 2 is two-dimensional layered structure and crystallized in triclinic with space group P1. Central Zn2+ is five-coordinated forming a distorted trigonal bipyramid coordination geometry. In addition, the interaction of complexes and ligand with EB-DNA were also studied by EtBr fluorescence probe. The interaction of complexes with DNA is stronger than ligand.
2018, 34(5): 981-988
doi: 10.11862/CJIC.2018.131
Abstract:
A 0D tetranuclear nickel(Ⅱ) coordination compound and a 1D manganese(Ⅱ) coordination polymer, namely[Ni2(μ3-Hbptc) (Hbptc)(phen)3(H2O)]2·4H2O (1) and {[Mn3(μ4-cptc)2(2, 2'-bipy)2(H2O)4]·2H2O}n (2), have been constr-ucted hydrothermally using H3bptc (H3bptc=biphenyl-2, 5, 3'-tricarboxylate acid), H3cptc (H3cptc=2-(4-carboxypyri-din-3-yl)terephalic acid), phen (phen=1, 10-phenanthroline) or 2, 2'-bipy (2, 2'-bipy=2, 2'-bipyridine), and nickel or manganese chlorides. Single-crystal X-ray diffraction analyses revealed that both compounds crystallize in the triclinic system, space group P1. In compound 1, two μ3-Hbptc2- ligands bridge alternately neighboring Ni(Ⅱ) ions to form a discrete tetranuclear nickel(Ⅱ) structure. These Ni4 units are assembled to a 3D supramolecular framework through O-H…O hydrogen bond. In compound 2, three neighboring Mn(Ⅱ) ions are bridged by four different μ4-cptc3- ligands, giving rise to a centrosymmetric trinuclear Mn(Ⅱ) subunit. The adjacent Mn3 subunits are further linked by the cptc3- blocks into a 1D chain. Magnetic studies for compounds 1 and 2 demonstrate an antiferro-magnetic coupling between the adjacent metal centers.
A 0D tetranuclear nickel(Ⅱ) coordination compound and a 1D manganese(Ⅱ) coordination polymer, namely[Ni2(μ3-Hbptc) (Hbptc)(phen)3(H2O)]2·4H2O (1) and {[Mn3(μ4-cptc)2(2, 2'-bipy)2(H2O)4]·2H2O}n (2), have been constr-ucted hydrothermally using H3bptc (H3bptc=biphenyl-2, 5, 3'-tricarboxylate acid), H3cptc (H3cptc=2-(4-carboxypyri-din-3-yl)terephalic acid), phen (phen=1, 10-phenanthroline) or 2, 2'-bipy (2, 2'-bipy=2, 2'-bipyridine), and nickel or manganese chlorides. Single-crystal X-ray diffraction analyses revealed that both compounds crystallize in the triclinic system, space group P1. In compound 1, two μ3-Hbptc2- ligands bridge alternately neighboring Ni(Ⅱ) ions to form a discrete tetranuclear nickel(Ⅱ) structure. These Ni4 units are assembled to a 3D supramolecular framework through O-H…O hydrogen bond. In compound 2, three neighboring Mn(Ⅱ) ions are bridged by four different μ4-cptc3- ligands, giving rise to a centrosymmetric trinuclear Mn(Ⅱ) subunit. The adjacent Mn3 subunits are further linked by the cptc3- blocks into a 1D chain. Magnetic studies for compounds 1 and 2 demonstrate an antiferro-magnetic coupling between the adjacent metal centers.
2018, 34(5): 989-996
doi: 10.11862/CJIC.2018.124
Abstract:
Hierarchical ZSM-5 zeolites with regular spherical structure were successfully synthesized via a facile two stage varying temperature crystallization using tetrapropylammonium hydroxide (TPAOH) as the single template. The fabricated samples were characterized by means of XRD, FT-IR, NH3-TPD, SEM, TEM and N2 adsorption-desorption isotherms. The results indicate that the spherical ZSM-5 zeolite particles with around 2 μm in diameter possess intercrystalline meso-and macropores generated from the aggregation of bar-shape ZSM-5 nanocrystals, which exhibit large specific surface area and mesopore volume. Compared to the ZSM-5 zeolite synthesized by constant temperature hydrothermal method, the hierarchical ZSM-5 zeolites have higher Brønsted acid to Lewis acid ratio (CBP/CLP) and strong acid to weak acid ratio (Cs/Cw), as well as the enhanced accessibility of the active sites, which were very important to the catalytic reaction. Catalytic tests reveal that hierarchical ZSM-5-contained catalytic cracking catalyst exhibit an outstanding performance in improving the propylene yield and conversion due to the enhancement of accessibility.
Hierarchical ZSM-5 zeolites with regular spherical structure were successfully synthesized via a facile two stage varying temperature crystallization using tetrapropylammonium hydroxide (TPAOH) as the single template. The fabricated samples were characterized by means of XRD, FT-IR, NH3-TPD, SEM, TEM and N2 adsorption-desorption isotherms. The results indicate that the spherical ZSM-5 zeolite particles with around 2 μm in diameter possess intercrystalline meso-and macropores generated from the aggregation of bar-shape ZSM-5 nanocrystals, which exhibit large specific surface area and mesopore volume. Compared to the ZSM-5 zeolite synthesized by constant temperature hydrothermal method, the hierarchical ZSM-5 zeolites have higher Brønsted acid to Lewis acid ratio (CBP/CLP) and strong acid to weak acid ratio (Cs/Cw), as well as the enhanced accessibility of the active sites, which were very important to the catalytic reaction. Catalytic tests reveal that hierarchical ZSM-5-contained catalytic cracking catalyst exhibit an outstanding performance in improving the propylene yield and conversion due to the enhancement of accessibility.
2018, 34(5): 997-1006
doi: 10.11862/CJIC.2018.125
Abstract:
Heterobinuclear 3d-4f complexes having chemical formulae[Cu(L)Nd(NO3)3(C2H5OH)] (1) and[Zn(L)(OAc)Ce(NO3)2(CH3OH)] (2) with a Salamo-type ligand O, O'-(ethane-1, 2-diyl)bis(1-(3-ethoxy-2-hydroxyphenyl)-3-ethoxy-2-hydroxybenzaldehyde oxime) (H2L)were synthesized, and characterized by elemental analyses, IR, UV-Vis, fluorescence spectra and X-ray crystallography. Complex 1 is an asymmetrical dinuclear complex, the pentacoordinate Cu(Ⅱ) ion has a slightly distorted square pyramidal geometry, and deca-coordinated Nd(Ⅲ) ion possesses a distorted bicapped twelve surface geometry. Complex 2 is also an asymmetrical dinuclear complex, the penta-coordinate Zn(Ⅱ) ion bears a distorted square pyramidal geometry too, and deca-coordinated Ce(Ⅲ) ion adopts a distorted bicapped twelve surface geometry. Compared with the ligand H2L, complex 1 showed fluorescence quenching, while complex 2 exhibited the fluorescence enhancement when the excitation wavelength is 318 nm.
Heterobinuclear 3d-4f complexes having chemical formulae[Cu(L)Nd(NO3)3(C2H5OH)] (1) and[Zn(L)(OAc)Ce(NO3)2(CH3OH)] (2) with a Salamo-type ligand O, O'-(ethane-1, 2-diyl)bis(1-(3-ethoxy-2-hydroxyphenyl)-3-ethoxy-2-hydroxybenzaldehyde oxime) (H2L)were synthesized, and characterized by elemental analyses, IR, UV-Vis, fluorescence spectra and X-ray crystallography. Complex 1 is an asymmetrical dinuclear complex, the pentacoordinate Cu(Ⅱ) ion has a slightly distorted square pyramidal geometry, and deca-coordinated Nd(Ⅲ) ion possesses a distorted bicapped twelve surface geometry. Complex 2 is also an asymmetrical dinuclear complex, the penta-coordinate Zn(Ⅱ) ion bears a distorted square pyramidal geometry too, and deca-coordinated Ce(Ⅲ) ion adopts a distorted bicapped twelve surface geometry. Compared with the ligand H2L, complex 1 showed fluorescence quenching, while complex 2 exhibited the fluorescence enhancement when the excitation wavelength is 318 nm.
