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2022 Volume 38 Issue 6
2022, 38(6): 977-992
doi: 10.11862/CJIC.2022.122
Abstract:
Exploring solid electrolytes with high ion conductivity, good chemical/electrochemical stability, and excellent electrode compatibility is crucial for developing solid-state batteries. Compared with other solid electrolytes, sulfide solid electrolytes possess the advantages of high ionic conductivity and good mechanical processing performance and are expected to be one of the most promising practical solid electrolytes. Among sulfide electrolytes, Li7P3S11 is highly attractive due to its high ionic conductivity and lower raw material costs. In this review, the structure, Li+ conduction mechanism, and synthetic routes of Li7P3S11 electrolyte are described firstly. Then, the current modification strategies utilized to improve the ionic conductivity, air/water stability, and electrochemical stability are recapped, and the applications of Li7P3S11 electrolyte both in all-solid-state lithium-sulfur batteries and all-solid-state batteries with commercial cathode materials are systematically summarized. Finally, the challenges and the development trend for Li7P3S11 electrolyte and its applications are provided.
Exploring solid electrolytes with high ion conductivity, good chemical/electrochemical stability, and excellent electrode compatibility is crucial for developing solid-state batteries. Compared with other solid electrolytes, sulfide solid electrolytes possess the advantages of high ionic conductivity and good mechanical processing performance and are expected to be one of the most promising practical solid electrolytes. Among sulfide electrolytes, Li7P3S11 is highly attractive due to its high ionic conductivity and lower raw material costs. In this review, the structure, Li+ conduction mechanism, and synthetic routes of Li7P3S11 electrolyte are described firstly. Then, the current modification strategies utilized to improve the ionic conductivity, air/water stability, and electrochemical stability are recapped, and the applications of Li7P3S11 electrolyte both in all-solid-state lithium-sulfur batteries and all-solid-state batteries with commercial cathode materials are systematically summarized. Finally, the challenges and the development trend for Li7P3S11 electrolyte and its applications are provided.
2022, 38(6): 993-1015
doi: 10.11862/CJIC.2022.120
Abstract:
Due to their characteristics of atomic-scale thickness, 1-2 eV varying band gaps with the number of layers, high carrier mobility (for example, the carrier mobility of MoS2 can reach 200 cm2·V-1·s-1), etc., two-dimensional transition metal dichalcogenides (TMDs) have been regarded as one of the potential candidates in the fields of optics and electronics applications. Compared to their bulk counterparts, the properties of TMDs can be more easily influ- enced by defect engineering due to their ultrathin feature. In this review, based on the introduction of TMDs crystal structure and phase, the defects classification is made according to their dimension. Then from two aspects, defect suppression and repair, as well as defect manufacturing, the latest research progress of defect engineering is summa- rized. On this basis, defect engineering applications in the fields of electronics, optics, magnetism, electrocatalysis, etc. are introduced. Finally, this review discusses the practical problems in defect engineering and prospects the future research and development directions in this domain.
Due to their characteristics of atomic-scale thickness, 1-2 eV varying band gaps with the number of layers, high carrier mobility (for example, the carrier mobility of MoS2 can reach 200 cm2·V-1·s-1), etc., two-dimensional transition metal dichalcogenides (TMDs) have been regarded as one of the potential candidates in the fields of optics and electronics applications. Compared to their bulk counterparts, the properties of TMDs can be more easily influ- enced by defect engineering due to their ultrathin feature. In this review, based on the introduction of TMDs crystal structure and phase, the defects classification is made according to their dimension. Then from two aspects, defect suppression and repair, as well as defect manufacturing, the latest research progress of defect engineering is summa- rized. On this basis, defect engineering applications in the fields of electronics, optics, magnetism, electrocatalysis, etc. are introduced. Finally, this review discusses the practical problems in defect engineering and prospects the future research and development directions in this domain.
2022, 38(6): 1016-1022
doi: 10.11862/CJIC.2022.123
Abstract:
Li4SrCa(SiO4)2∶Eu3+ red phosphor was synthesized by a high-temperature solid-phase method using silicate as a host material. The phase, morphology, and luminescence properties of the powder were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, and fluorescence spectroscopy. The results showed that the crystal structure does not change after the addition of the europium ion. Under the light excitation at 393 nm, the emission peak intensity of the sample was the strongest at 693 nm. With 693 nm as the monitoring wavelength, the main excitation peaks were 361 nm (7F0→5D4), 375 nm (7F0→5G3), 413 nm (7F0→5D3), 393 nm (7F0→5L6), and 464 nm (7F0→5D2), which suggests that the phosphor has good absorption to near-ultraviolet and blue light, and has the potential to produce white light-emitting diodes. The effect of Eu3+ doped concentration on the luminescence intensity of phosphor was studied by emission spectroscopy. When the doped concentration of europi- um ion (molar fraction, x) was equal to 0.10, the emission intensity of the sample was the strongest, and the sample emitted red light. The mechanism of concentration quenching was analyzed by the relationship between Dexter strength and concentration.
Li4SrCa(SiO4)2∶Eu3+ red phosphor was synthesized by a high-temperature solid-phase method using silicate as a host material. The phase, morphology, and luminescence properties of the powder were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, and fluorescence spectroscopy. The results showed that the crystal structure does not change after the addition of the europium ion. Under the light excitation at 393 nm, the emission peak intensity of the sample was the strongest at 693 nm. With 693 nm as the monitoring wavelength, the main excitation peaks were 361 nm (7F0→5D4), 375 nm (7F0→5G3), 413 nm (7F0→5D3), 393 nm (7F0→5L6), and 464 nm (7F0→5D2), which suggests that the phosphor has good absorption to near-ultraviolet and blue light, and has the potential to produce white light-emitting diodes. The effect of Eu3+ doped concentration on the luminescence intensity of phosphor was studied by emission spectroscopy. When the doped concentration of europi- um ion (molar fraction, x) was equal to 0.10, the emission intensity of the sample was the strongest, and the sample emitted red light. The mechanism of concentration quenching was analyzed by the relationship between Dexter strength and concentration.
2022, 38(6): 1023-1036
doi: 10.11862/CJIC.2022.097
Abstract:
Three amphiphilic block copolymers 1s-TPE-PCL-b-PNIPAM, 2s-TPE-PCL-b-PNIPAM, and 4s-TPE-PCL -b-PNIPAM (PCL=polycaprolactone, PNIPAM=poly(N - isopropylacrylamide)) were synthesized by in situ polymerization with tetraphenylethylene (TPE) fluorescent small molecules as the center. Then, the rare earth element Eu(Ⅲ) was coordinated with the hydrophilic fragment PNIPAM to synthesize block copolymer-Eu(Ⅲ) complexes (1s-TPE-PCL-b-PNIPAM-Eu(Ⅲ) for one-arm, 2s-TPE-PCL-b -PNIPAM-Eu(Ⅲ) for two-arm, and 4s-TPE-PCL-b-PNIPAM-Eu(Ⅲ) for four-arm). Finally, non-semiconductor polymer dots (Pdots) were prepared by self-assembly of the complexes in water. The three kinds of Pdots had excellent water solubility and ultra-small particle size below 5 nm (average particle sizes were 4.8, 4.3, and 2.7 nm, respectively). The optical test results showed that the single, double, and fourarm Pdots mainly emitted blue light at 430 nm under the excitation of 360 nm, and exhibited excellent aggregation-induced emission characteristics. At 395 nm, the red emission was mainly at 615 nm, and there had little mutual interference because of blue-red emission wavelength spacing was as high as 195 nm, showing excellent double fluorescence properties. The four-arm Pdots aqueous solution had a wider range of color changes and a better double fluorescence effect. In addition, the lower critical solution temperatures (LCSTs) of the three Pdots were 32, 36, and 37 ℃, respectively. While the LCSTs of the four -arm Pdots were closer to the normal body temperature. At the same time, the conformation of the PNIPAM chain in Pdots changed from expansion state to contraction state along with the increase of temperature. As a result, the aggregation degree of TPE on the chain was enhanced, which caused the temperature response of Pdots aqueous solution fluorescence. Ultimately, cytotoxicity and cell imaging studies showed that the three Pdots had low cytotoxicity and could enter HeLa, A549, and HepG2 tumor cells by endocytosis. Under different excitation wavelengths, strong blue or red fluorescence signals could be received in the cells, exhibiting blue/red dual-color fluorescence imaging ability and reversible dual-color fluorescence switching function. In addition, the comparison of the three Pdots found that the four-arm Pdots had the smallest particle size, the best dual fluorescence performance, and the best cell imaging effect.
Three amphiphilic block copolymers 1s-TPE-PCL-b-PNIPAM, 2s-TPE-PCL-b-PNIPAM, and 4s-TPE-PCL -b-PNIPAM (PCL=polycaprolactone, PNIPAM=poly(N - isopropylacrylamide)) were synthesized by in situ polymerization with tetraphenylethylene (TPE) fluorescent small molecules as the center. Then, the rare earth element Eu(Ⅲ) was coordinated with the hydrophilic fragment PNIPAM to synthesize block copolymer-Eu(Ⅲ) complexes (1s-TPE-PCL-b-PNIPAM-Eu(Ⅲ) for one-arm, 2s-TPE-PCL-b -PNIPAM-Eu(Ⅲ) for two-arm, and 4s-TPE-PCL-b-PNIPAM-Eu(Ⅲ) for four-arm). Finally, non-semiconductor polymer dots (Pdots) were prepared by self-assembly of the complexes in water. The three kinds of Pdots had excellent water solubility and ultra-small particle size below 5 nm (average particle sizes were 4.8, 4.3, and 2.7 nm, respectively). The optical test results showed that the single, double, and fourarm Pdots mainly emitted blue light at 430 nm under the excitation of 360 nm, and exhibited excellent aggregation-induced emission characteristics. At 395 nm, the red emission was mainly at 615 nm, and there had little mutual interference because of blue-red emission wavelength spacing was as high as 195 nm, showing excellent double fluorescence properties. The four-arm Pdots aqueous solution had a wider range of color changes and a better double fluorescence effect. In addition, the lower critical solution temperatures (LCSTs) of the three Pdots were 32, 36, and 37 ℃, respectively. While the LCSTs of the four -arm Pdots were closer to the normal body temperature. At the same time, the conformation of the PNIPAM chain in Pdots changed from expansion state to contraction state along with the increase of temperature. As a result, the aggregation degree of TPE on the chain was enhanced, which caused the temperature response of Pdots aqueous solution fluorescence. Ultimately, cytotoxicity and cell imaging studies showed that the three Pdots had low cytotoxicity and could enter HeLa, A549, and HepG2 tumor cells by endocytosis. Under different excitation wavelengths, strong blue or red fluorescence signals could be received in the cells, exhibiting blue/red dual-color fluorescence imaging ability and reversible dual-color fluorescence switching function. In addition, the comparison of the three Pdots found that the four-arm Pdots had the smallest particle size, the best dual fluorescence performance, and the best cell imaging effect.
2022, 38(6): 1037-1048
doi: 10.11862/CJIC.2022.110
Abstract:
Zirconium-based metal-organic frameworks (UiO-66) nanomaterials with 2-amino terephthalic acid as a ligand was synthesized by the solvothermal method. PAN/UiO-66 fibers with free-dispersed UiO-66 nanoparticles were prepared by electrospinning. Porous carbon nanofibers (PCNFs) were prepared by controllable pyrolysis. Pd nanoparticles were deposited on the surface of PCNFs by the wet-chemistry reduction method to obtain PCNFs@Pd composites. The morphologies, compositions, and structures of PCNFs@Pd were characterized by scanning electron microscope, transmission electron microscope, and X -ray diffraction. The performances of oxygen reduction reaction (ORR) of PCNFs@Pd were tested by electrochemical workstations in 0.1 mol·L-1 KOH and 0.1 mol·L-1 HClO4 electrolytes, respectively. It was found that adding UiO-66 into PAN fibers significantly improved the ORR performance of PCNFs@Pd (0.34% of Pd loading) composites. Compared with 40%Pt/C, PCNFs@Pd composites in alkaline electrolytes showed lower Tafel slope, better cycle stability, and methanol toxicity resistance. Moreover, the catalytic activity and cycle stability of PCNFs@Pd were comparable to that of 20%Pt/C in acidic electrolytes.
Zirconium-based metal-organic frameworks (UiO-66) nanomaterials with 2-amino terephthalic acid as a ligand was synthesized by the solvothermal method. PAN/UiO-66 fibers with free-dispersed UiO-66 nanoparticles were prepared by electrospinning. Porous carbon nanofibers (PCNFs) were prepared by controllable pyrolysis. Pd nanoparticles were deposited on the surface of PCNFs by the wet-chemistry reduction method to obtain PCNFs@Pd composites. The morphologies, compositions, and structures of PCNFs@Pd were characterized by scanning electron microscope, transmission electron microscope, and X -ray diffraction. The performances of oxygen reduction reaction (ORR) of PCNFs@Pd were tested by electrochemical workstations in 0.1 mol·L-1 KOH and 0.1 mol·L-1 HClO4 electrolytes, respectively. It was found that adding UiO-66 into PAN fibers significantly improved the ORR performance of PCNFs@Pd (0.34% of Pd loading) composites. Compared with 40%Pt/C, PCNFs@Pd composites in alkaline electrolytes showed lower Tafel slope, better cycle stability, and methanol toxicity resistance. Moreover, the catalytic activity and cycle stability of PCNFs@Pd were comparable to that of 20%Pt/C in acidic electrolytes.
2022, 38(6): 1049-1058
doi: 10.11862/CJIC.2022.112
Abstract:
Synthesis of imine compounds via benzylamine oxidative coupling has become one of the most ideal methods due to its high atom economy and environmental friendliness. The key is to develop high - performance non-noble metal-based heterogeneous catalysts. In this work, a vanadium-nitrogen co-doped porous carbon (V-N-C) catalyst was prepared via high-temperature pyrolysis (900 ℃ for 2 h in an inert atmosphere) combined with acidleaching (1 mol·L-1 HCl solution at 120 ℃ for 12 h) approach by using biomass chitosan as the sacrificial template, vanadium acetylacetonate as the source of metal vanadium, and ZnCl2 as the pore-forming agent. Various characterization techniques including a high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) investigation were used to analyze the composition, structure, vanadium species size, content, and other physical and chemical properties of the catalyst, and its catalytic performance was evaluated in the oxidative cou-pling reaction of benzylamine. The characterization results showed that the specific surface area of the V-N-C catalyst was as high as 1 470 m2·g-1, the pore volume was 1.06 cm3·g-1, and the mass fraction of the vanadium species was 0.19% that were highly dispersed on the support likely in the form of single atoms (VNx). In the oxidative selfcoupling reaction of benzylamine to the imine (reaction conditions: toluene as solvent, 110 ℃, 1.01×105 Pa O2, 12 h), the developed V-N-C exhibited excellent activity (99%), exclusive selectivity (99%), outperforming the homogeneous VO(acac)2 and heterogeneous V2O5 catalysts. Moreover, V-N-C was repeatedly used 9 times without any decay in reactivity and stability. Furthermore, V-N-C presented excellent universality for a series of substrates containing different functional groups. Mechanism studies indicated that the reaction steps were involved in the initial formation of benzylimine and H2O2 intermediates by activating benzylamine and oxygen molecules, respectively, on the VNx and defect sites of V-N-C, then benzylimine and benzylamine condensed to release an NH3 molecule to gener-ate the target product imine.
Synthesis of imine compounds via benzylamine oxidative coupling has become one of the most ideal methods due to its high atom economy and environmental friendliness. The key is to develop high - performance non-noble metal-based heterogeneous catalysts. In this work, a vanadium-nitrogen co-doped porous carbon (V-N-C) catalyst was prepared via high-temperature pyrolysis (900 ℃ for 2 h in an inert atmosphere) combined with acidleaching (1 mol·L-1 HCl solution at 120 ℃ for 12 h) approach by using biomass chitosan as the sacrificial template, vanadium acetylacetonate as the source of metal vanadium, and ZnCl2 as the pore-forming agent. Various characterization techniques including a high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) investigation were used to analyze the composition, structure, vanadium species size, content, and other physical and chemical properties of the catalyst, and its catalytic performance was evaluated in the oxidative cou-pling reaction of benzylamine. The characterization results showed that the specific surface area of the V-N-C catalyst was as high as 1 470 m2·g-1, the pore volume was 1.06 cm3·g-1, and the mass fraction of the vanadium species was 0.19% that were highly dispersed on the support likely in the form of single atoms (VNx). In the oxidative selfcoupling reaction of benzylamine to the imine (reaction conditions: toluene as solvent, 110 ℃, 1.01×105 Pa O2, 12 h), the developed V-N-C exhibited excellent activity (99%), exclusive selectivity (99%), outperforming the homogeneous VO(acac)2 and heterogeneous V2O5 catalysts. Moreover, V-N-C was repeatedly used 9 times without any decay in reactivity and stability. Furthermore, V-N-C presented excellent universality for a series of substrates containing different functional groups. Mechanism studies indicated that the reaction steps were involved in the initial formation of benzylimine and H2O2 intermediates by activating benzylamine and oxygen molecules, respectively, on the VNx and defect sites of V-N-C, then benzylimine and benzylamine condensed to release an NH3 molecule to gener-ate the target product imine.
2022, 38(6): 1059-1072
doi: 10.11862/CJIC.2022.113
Abstract:
Firstly, ZnIn2S4 was modified by the up-conversion photoluminescence (UCPL) properties of carbon quantum dots (CQDs), and AgIn 5S8/CQDs/ZnIn 2S4 composite was prepared by ion - exchange method. X - ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV-Vis diffuse reflectance spectroscopy (UV-VIS DRS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), nitrogen adsorption-desorption test, photoluminescence (PL), and electrochemical impedance (EIS) were used to characterize the composition, structure, morphology, surface physical, and chemical properties of the composite. The results show that the synergistic effect between the different components in the composite results in a broad spectral response (250 - 800 nm). Compared with the comparative system, AgIn5S 8/CQDs/ZnIn2S 4 exhibited significantly enhanced photocurrent density, smaller charge transfer resistance, and prolonged photo - generated carrier lifetime. The photocatalytic activity of AgIn5S 8 /CQDs/ ZnIn2S4 was studied under different light sources using methyl orange as the model molecule. The results showed that AgIn5S8/CQDs/ZnIn2S4 had an enhanced photocatalytic activity. At the same time, the composite not only had a high photolysis water hydrogen production capacity (312.09 μmol·h-1·g-1) but also had good stability.
Firstly, ZnIn2S4 was modified by the up-conversion photoluminescence (UCPL) properties of carbon quantum dots (CQDs), and AgIn 5S8/CQDs/ZnIn 2S4 composite was prepared by ion - exchange method. X - ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV-Vis diffuse reflectance spectroscopy (UV-VIS DRS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), nitrogen adsorption-desorption test, photoluminescence (PL), and electrochemical impedance (EIS) were used to characterize the composition, structure, morphology, surface physical, and chemical properties of the composite. The results show that the synergistic effect between the different components in the composite results in a broad spectral response (250 - 800 nm). Compared with the comparative system, AgIn5S 8/CQDs/ZnIn2S 4 exhibited significantly enhanced photocurrent density, smaller charge transfer resistance, and prolonged photo - generated carrier lifetime. The photocatalytic activity of AgIn5S 8 /CQDs/ ZnIn2S4 was studied under different light sources using methyl orange as the model molecule. The results showed that AgIn5S8/CQDs/ZnIn2S4 had an enhanced photocatalytic activity. At the same time, the composite not only had a high photolysis water hydrogen production capacity (312.09 μmol·h-1·g-1) but also had good stability.
2022, 38(6): 1073-1080
doi: 10.11862/CJIC.2022.114
Abstract:
Amorphous La2Ti2O7∶Eu3+ phosphors were synthesized by the combustion method and characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), and photoluminescence spectra to study the structure, morphology, and luminescent properties. Then it was further applied in wheat growth lighting LEDs (lightemitting diodes) to investigate the illumination effect on growth rate and photosynthesis pigments of wheat. Compared with the crystalline sample synthesized by the solid-state method, the amorphous La2Ti2O7∶Eu3+ phosphor can increase the emission intensity of 7F2 energy-level transition relative to 7F1 energy-level from 2.8 to 5.3 by reducing the coordination environment symmetry around Eu3+ ions, and the emission peak showed a redshift from 611 to 613 nm. The amorphous La2Ti2O7∶Eu3+ phosphor exhibited a color coordinate of (0.661, 0.339) and a color purity of 95.9% as compared with 90.9% of the crystalline sample, which is more suitable for applications in plant growth lighting LEDs. The amorphous La2Ti2O7∶Eu3+ phosphor overcomes the problem of low luminous efficiency of Eu3+ ions in the amorphous host, which achieved a high internal quantum efficiency of 79.8% and an external quantum efficiency of 43.0%. Besides, the emission intensity of the amorphous La2Ti2O7∶Eu3+ phosphor at 150 ℃ can maintain 46.3% of that at room temperature. Finally, the as-fabricated LED lamp can accelerate the growth rate of wheat, resulting in an improvement of 28% of the content of chlorophyll and carotene, which shows a potential to be applied in agricultural lighting LEDs.
Amorphous La2Ti2O7∶Eu3+ phosphors were synthesized by the combustion method and characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), and photoluminescence spectra to study the structure, morphology, and luminescent properties. Then it was further applied in wheat growth lighting LEDs (lightemitting diodes) to investigate the illumination effect on growth rate and photosynthesis pigments of wheat. Compared with the crystalline sample synthesized by the solid-state method, the amorphous La2Ti2O7∶Eu3+ phosphor can increase the emission intensity of 7F2 energy-level transition relative to 7F1 energy-level from 2.8 to 5.3 by reducing the coordination environment symmetry around Eu3+ ions, and the emission peak showed a redshift from 611 to 613 nm. The amorphous La2Ti2O7∶Eu3+ phosphor exhibited a color coordinate of (0.661, 0.339) and a color purity of 95.9% as compared with 90.9% of the crystalline sample, which is more suitable for applications in plant growth lighting LEDs. The amorphous La2Ti2O7∶Eu3+ phosphor overcomes the problem of low luminous efficiency of Eu3+ ions in the amorphous host, which achieved a high internal quantum efficiency of 79.8% and an external quantum efficiency of 43.0%. Besides, the emission intensity of the amorphous La2Ti2O7∶Eu3+ phosphor at 150 ℃ can maintain 46.3% of that at room temperature. Finally, the as-fabricated LED lamp can accelerate the growth rate of wheat, resulting in an improvement of 28% of the content of chlorophyll and carotene, which shows a potential to be applied in agricultural lighting LEDs.
2022, 38(6): 1081-1089
doi: 10.11862/CJIC.2022.124
Abstract:
Two organotin complexes (C1, C2) were synthesized by di(2, 4-dichlorobenzyl)tin dichloride reacting with p-methyl benzoyl hydrazide or p-tert-butyl benzoyl hydrazide, and sodium pyruvate. The structure of the complexes were characterized through elemental analysis, IR, 1H NMR, 13C NMR, 119Sn NMR, HRMS, and X-ray single crystal diffraction. The thermal stability of complexes C1 and C2 were analyzed, and the antitumor activities of the complexes were evaluated by MTT against three cell lines (human lung cancer cells NCI-H460, human liver cancer cells HepG2, and human breast cancer cells MCF7). It was found that complex C1 showed a good inhibitory effect on NCI-H460, HepG2, and MCF7. The interaction of the complexes with DNA was investigated using UV-Vis spectroscopy, fluorescence spectroscopy, and viscosity measurement. It is found that the complexes can bind to DNA through an intercalation mode. CCDC: 2124763, C1; 2124764, C2.
Two organotin complexes (C1, C2) were synthesized by di(2, 4-dichlorobenzyl)tin dichloride reacting with p-methyl benzoyl hydrazide or p-tert-butyl benzoyl hydrazide, and sodium pyruvate. The structure of the complexes were characterized through elemental analysis, IR, 1H NMR, 13C NMR, 119Sn NMR, HRMS, and X-ray single crystal diffraction. The thermal stability of complexes C1 and C2 were analyzed, and the antitumor activities of the complexes were evaluated by MTT against three cell lines (human lung cancer cells NCI-H460, human liver cancer cells HepG2, and human breast cancer cells MCF7). It was found that complex C1 showed a good inhibitory effect on NCI-H460, HepG2, and MCF7. The interaction of the complexes with DNA was investigated using UV-Vis spectroscopy, fluorescence spectroscopy, and viscosity measurement. It is found that the complexes can bind to DNA through an intercalation mode. CCDC: 2124763, C1; 2124764, C2.
2022, 38(6): 1090-1102
doi: 10.11862/CJIC.2022.115
Abstract:
Aromatization of light olefins in methanol to aromatics via a two-step route showed better catalytic stability. To analyze the intrinsic mechanism, a series of ZSM-5 catalysts with different SiO2/Al2O3 ratios and Zn modified were prepared. Then propene aromatization, as the model reaction, was performed to analyze the effects of acidity on aromatization of light olefins and explore the reaction mechanism. The results illustrated that the increased acid density was in favor of the hydrogen transfer process, resulting in an increase of aromatics selectivity from 31.0% to 34.4% with the SiO2/Al2O3 ratio decreased from 150 to 75. Meanwhile, an increase in acid density will cause more propene to directly participate in the hydrogen transfer reaction to produce propane which was enhanced from 28.2% to 36.0%. Further introducing Zn could transform some Brønsted acid sites into Zn-Lewis acid sites, the aromatics selectivity was further significantly increased to 62.4% with the enhancement of the alkenes dehydrogenation aromatization process. Compared with direct methanol aromatization, propene aromatization had a less deep alkylation process, which not only increased the aromatics selectivity, but also inhibited the formation of insoluble coke, and improved the catalytic stability. These results suggested that the pre-conversion of methanol in methanol to light olefins was an important reason for the high catalytic stability of two-step methanol conversions, which inhibited the deep alkylation of aromatics in the subsequent aromatization process.
Aromatization of light olefins in methanol to aromatics via a two-step route showed better catalytic stability. To analyze the intrinsic mechanism, a series of ZSM-5 catalysts with different SiO2/Al2O3 ratios and Zn modified were prepared. Then propene aromatization, as the model reaction, was performed to analyze the effects of acidity on aromatization of light olefins and explore the reaction mechanism. The results illustrated that the increased acid density was in favor of the hydrogen transfer process, resulting in an increase of aromatics selectivity from 31.0% to 34.4% with the SiO2/Al2O3 ratio decreased from 150 to 75. Meanwhile, an increase in acid density will cause more propene to directly participate in the hydrogen transfer reaction to produce propane which was enhanced from 28.2% to 36.0%. Further introducing Zn could transform some Brønsted acid sites into Zn-Lewis acid sites, the aromatics selectivity was further significantly increased to 62.4% with the enhancement of the alkenes dehydrogenation aromatization process. Compared with direct methanol aromatization, propene aromatization had a less deep alkylation process, which not only increased the aromatics selectivity, but also inhibited the formation of insoluble coke, and improved the catalytic stability. These results suggested that the pre-conversion of methanol in methanol to light olefins was an important reason for the high catalytic stability of two-step methanol conversions, which inhibited the deep alkylation of aromatics in the subsequent aromatization process.
2022, 38(6): 1103-1111
doi: 10.11862/CJIC.2022.125
Abstract:
Two new binuclear Ln(Ⅲ)-based complexes with the formula [Ln2(dbm)2(L)2(C2H5OH)2] (Ln=Dy (1), Nd (2); dbm-=1, 3-dioxo-1, 3-diphenylpropan-2-ide) have been synthesized via the solvothermal method by using a polydentate Schiff base ligand (H2L=(E)-N′-(3-ethoxy-2-hydroxybenzylidene)-3-hydroxypicolinohydrazide) reacting with Ln(dbm)3·2H2O. Single-crystal X-ray structures reveal that complexes 1 and 2 are mainly composed of two Ln(Ⅲ) ions, two dbm-ions, two L2-ions, and two C2H5OH molecules, and the two central Ln(Ⅲ) ions are connected by two μ2-O atoms forming a "parallelogram-shaped" Ln2O2 core. Magnetic studies show that the ferromagnetic interaction exists between the adjacent two Dy(Ⅲ) ions and single-molecule magnet behavior occurs in 1. CCDC: 2100188, 1; 2133336, 2.
Two new binuclear Ln(Ⅲ)-based complexes with the formula [Ln2(dbm)2(L)2(C2H5OH)2] (Ln=Dy (1), Nd (2); dbm-=1, 3-dioxo-1, 3-diphenylpropan-2-ide) have been synthesized via the solvothermal method by using a polydentate Schiff base ligand (H2L=(E)-N′-(3-ethoxy-2-hydroxybenzylidene)-3-hydroxypicolinohydrazide) reacting with Ln(dbm)3·2H2O. Single-crystal X-ray structures reveal that complexes 1 and 2 are mainly composed of two Ln(Ⅲ) ions, two dbm-ions, two L2-ions, and two C2H5OH molecules, and the two central Ln(Ⅲ) ions are connected by two μ2-O atoms forming a "parallelogram-shaped" Ln2O2 core. Magnetic studies show that the ferromagnetic interaction exists between the adjacent two Dy(Ⅲ) ions and single-molecule magnet behavior occurs in 1. CCDC: 2100188, 1; 2133336, 2.
2022, 38(6): 1112-1120
doi: 10.11862/CJIC.2022.109
Abstract:
A coordination polymer, formulated as {[Cu(HDTTA)2(DMF)(H2O)]·DMF·H2O}n (1) (D-H2DTTA=(+) -di-p-toluoyl-D-tartaric acid, DMF=N, N-dimethylformamide), has been synthesized. Its structure was characterized by IR spectrum, elemental analysis, X-ray single-crystal diffraction, and powder X-ray diffraction. Complex 1 features a 1D chain structure along the a-axis and forms a 2D layered structure in the ab plane through weak intermolecular interactions. The thermal decomposition process of 1 included the loss of solvent molecules below 197 ℃ and follow-up decomposition of the main structure. Under the excitation of 300 nm, the fluorescence of the ligand was quenched by the coordinated Cu2+ cation. In addition, complex 1 exhibited a good and specific adsorption effect on methylene blue dye in an aqueous solution with an adsorption rate of 81% after 49 min.
A coordination polymer, formulated as {[Cu(HDTTA)2(DMF)(H2O)]·DMF·H2O}n (1) (D-H2DTTA=(+) -di-p-toluoyl-D-tartaric acid, DMF=N, N-dimethylformamide), has been synthesized. Its structure was characterized by IR spectrum, elemental analysis, X-ray single-crystal diffraction, and powder X-ray diffraction. Complex 1 features a 1D chain structure along the a-axis and forms a 2D layered structure in the ab plane through weak intermolecular interactions. The thermal decomposition process of 1 included the loss of solvent molecules below 197 ℃ and follow-up decomposition of the main structure. Under the excitation of 300 nm, the fluorescence of the ligand was quenched by the coordinated Cu2+ cation. In addition, complex 1 exhibited a good and specific adsorption effect on methylene blue dye in an aqueous solution with an adsorption rate of 81% after 49 min.
2022, 38(6): 1121-1132
doi: 10.11862/CJIC.2022.126
Abstract:
Rapid detection of organic compounds in wastewater has always been an important issue. Fluorescent Tb-based metal- organic gel MOG(Tb) was prepared by the metal ion exchange method. The studies have shown that trace amounts of furazolidone (FZD), metronidazole (MDZ), 2, 4-dinitrotoluene (2, 4-DNT), and 4-nitrophenol (4-NP) could effectively quench the fluorescence emission of MOG(Tb) even in the presence of other analytes, demonstrat-ing that the MOG(Tb) xerogels could effectively detect antibiotics (FZD, MDZ) and nitroaromatic compounds (2, 4-DNT, 4-NP). However, penicillin G potassium salt (PCLP) could enhance the fluorescence of MOG(Tb). In addi-tion, the recyclability and water stability tests of the MOG(Tb) xerogels were also carried out, and satisfactory results were obtained.
Rapid detection of organic compounds in wastewater has always been an important issue. Fluorescent Tb-based metal- organic gel MOG(Tb) was prepared by the metal ion exchange method. The studies have shown that trace amounts of furazolidone (FZD), metronidazole (MDZ), 2, 4-dinitrotoluene (2, 4-DNT), and 4-nitrophenol (4-NP) could effectively quench the fluorescence emission of MOG(Tb) even in the presence of other analytes, demonstrat-ing that the MOG(Tb) xerogels could effectively detect antibiotics (FZD, MDZ) and nitroaromatic compounds (2, 4-DNT, 4-NP). However, penicillin G potassium salt (PCLP) could enhance the fluorescence of MOG(Tb). In addi-tion, the recyclability and water stability tests of the MOG(Tb) xerogels were also carried out, and satisfactory results were obtained.
2022, 38(6): 1133-1145
doi: 10.11862/CJIC.2022.111
Abstract:
Three new coordination polymers based on V-shaped ligands, namely {[Cd(BIDPS)(PA)(H2O)]·CH3OH}n (1), {[Zn(BIDPS)(p-bdc)]·H2O}n (2) and [Mn(BIDPT)(NBA)]n (3) (BIDPS=4, 4' -bis(imidazol-l-yl)-phenyl sulphone, H2PA=pamoic acid, p - H2bdc= p - phthalic acid, BIDPT=4, 4' - bis(imidazol - l - yl)diphenyl thioether, H2NBA=4, 4' - azanediyl dibenzoic acid) have been hydrothermally synthesized and structurally characterized. Compounds 1 and 2 feature an undulate 2D layer structure. Compound 1 exhibits a rare 2D→3D inclined polycatenated structure, while compound 2 is further joined by intermolecular hydrogen bondings to form a 3D network. Compound 3 displays a 3-connected hexagonal layer hcb topology (honeycomb network) and is further assembled into a 3D network via C—H … π interaction. Compounds 1 and 2 showed excellent water stability and fluorescence, which were further con-firmed as bifunctional fluorescent sensors for Fe3+ and Cr2O72- with high selectivity, sensitivity, and anti-interference ability in the water. The mechanisms of fluorescence quenching were also studied in detail. CCDC: 1919698, 1; 2085947, 2; 2117923, 3.
Three new coordination polymers based on V-shaped ligands, namely {[Cd(BIDPS)(PA)(H2O)]·CH3OH}n (1), {[Zn(BIDPS)(p-bdc)]·H2O}n (2) and [Mn(BIDPT)(NBA)]n (3) (BIDPS=4, 4' -bis(imidazol-l-yl)-phenyl sulphone, H2PA=pamoic acid, p - H2bdc= p - phthalic acid, BIDPT=4, 4' - bis(imidazol - l - yl)diphenyl thioether, H2NBA=4, 4' - azanediyl dibenzoic acid) have been hydrothermally synthesized and structurally characterized. Compounds 1 and 2 feature an undulate 2D layer structure. Compound 1 exhibits a rare 2D→3D inclined polycatenated structure, while compound 2 is further joined by intermolecular hydrogen bondings to form a 3D network. Compound 3 displays a 3-connected hexagonal layer hcb topology (honeycomb network) and is further assembled into a 3D network via C—H … π interaction. Compounds 1 and 2 showed excellent water stability and fluorescence, which were further con-firmed as bifunctional fluorescent sensors for Fe3+ and Cr2O72- with high selectivity, sensitivity, and anti-interference ability in the water. The mechanisms of fluorescence quenching were also studied in detail. CCDC: 1919698, 1; 2085947, 2; 2117923, 3.
2022, 38(6): 1146-1158
doi: 10.11862/CJIC.2022.108
Abstract:
A luminescent Zn-complex based on the 3-(2, 4-dicarboxylphenyl)-6-carboxylpyridine (H3dpcp), namely [Zn(H2dpcp)2(H2O)2]·H2O (1), was successfully fabricated by the solvothermal process. Complex 1 features a mono-nuclear butterfly-like structure, which further extends to the 3D supramolecular architecture via π…π interactions. It is found that complex 1 exhibited excellent luminescent stability in a pH range of 1-10 in an aqueous solution. It should be noted that complex 1 can not only detect PO43- ion based on the turn-on effect with high selectivity and recyclability but also serve as a remarkably selective sensing material with the fluorescence quenching for Fe3+ ion. The examination of nitroaromatic compounds demonstrated that complex 1 also behaved as a functional probe with high selectivity, sensitivity, and the low detection limit of 2, 4, 6-trinitrophenol (TNP). Furthermore, the luminescent sensing mechanisms for the above analytes were also investigated in detail. CCDC: 2010615.
A luminescent Zn-complex based on the 3-(2, 4-dicarboxylphenyl)-6-carboxylpyridine (H3dpcp), namely [Zn(H2dpcp)2(H2O)2]·H2O (1), was successfully fabricated by the solvothermal process. Complex 1 features a mono-nuclear butterfly-like structure, which further extends to the 3D supramolecular architecture via π…π interactions. It is found that complex 1 exhibited excellent luminescent stability in a pH range of 1-10 in an aqueous solution. It should be noted that complex 1 can not only detect PO43- ion based on the turn-on effect with high selectivity and recyclability but also serve as a remarkably selective sensing material with the fluorescence quenching for Fe3+ ion. The examination of nitroaromatic compounds demonstrated that complex 1 also behaved as a functional probe with high selectivity, sensitivity, and the low detection limit of 2, 4, 6-trinitrophenol (TNP). Furthermore, the luminescent sensing mechanisms for the above analytes were also investigated in detail. CCDC: 2010615.
2022, 38(6): 1159-1170
doi: 10.11862/CJIC.2022.119
Abstract:
An electrochemical biosensor for non-enzyme glucose detection was constructed based on the synergistic action of gold (Au) nanoparticles and platinum (Pt) nanoparticles on the surface of a stainless steel acupuncture needle (AN), which was achieved by respectively electrodepositing. The functional interface (Pt/Au/AN) was characterized by a scanning electron microscope, showing that cabbage-like nanomaterials were uniformly and densely distributed on the surface of AN. Pt/Au/AN electrode also possessed outstanding electrochemical characteristics, which were studied by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Significantly, Pt/Au/AN electrode exhibited remarkably electrocatalytic activity toward glucose oxidation compared with Au/AN or Pt/AN electrode. The results indicated that the contact interface of bimetallic Pt/Au was the vital electrocatalytic site for glucose oxidation. A further study proved that the contact interface exhibited intrinsic features and distinct selectivity for sensing glucose. The prepared sensor showed a wide linear range from 0.1 to 35 mmol·L-1, and the detection limit of glucose was 0.076 3 mmol·L-1. The sensor showed great stability, excellent selectivity, and miniaturization. Furthermore, the sensor was successfully used for the detection of glucose in human serum.
An electrochemical biosensor for non-enzyme glucose detection was constructed based on the synergistic action of gold (Au) nanoparticles and platinum (Pt) nanoparticles on the surface of a stainless steel acupuncture needle (AN), which was achieved by respectively electrodepositing. The functional interface (Pt/Au/AN) was characterized by a scanning electron microscope, showing that cabbage-like nanomaterials were uniformly and densely distributed on the surface of AN. Pt/Au/AN electrode also possessed outstanding electrochemical characteristics, which were studied by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Significantly, Pt/Au/AN electrode exhibited remarkably electrocatalytic activity toward glucose oxidation compared with Au/AN or Pt/AN electrode. The results indicated that the contact interface of bimetallic Pt/Au was the vital electrocatalytic site for glucose oxidation. A further study proved that the contact interface exhibited intrinsic features and distinct selectivity for sensing glucose. The prepared sensor showed a wide linear range from 0.1 to 35 mmol·L-1, and the detection limit of glucose was 0.076 3 mmol·L-1. The sensor showed great stability, excellent selectivity, and miniaturization. Furthermore, the sensor was successfully used for the detection of glucose in human serum.
2022, 38(6): 1171-1179
doi: 10.11862/CJIC.2022.105
Abstract:
Four new organotin complexes based on m-phthaloyl bis(substituted salicylaldehyde acylhydrazone) (H4L), (SnR2)2L (1-4), were synthesized by solvothermal reaction of H4L with R32SnOH, or one-pot solvothermal reaction of m-phthaloyl hydrazide, 3-tert-butyl salicylaldehyde, and tricyclohexyltin hydroxide, where H4L=m-Ph (CONH—N=CH(o-OH)PhR1)2; R1=NEt2, R2=Ph (1); R1=3, 5-di-tert-butyl=3, 5-t-2Bu, R2=Ph (2); R1=3, 5-t-2Bu, R2=Cy (3); R1=3-tert-butyl=3-t-Bu, R2=Cy (4). And they were characterized by elemental analysis, IR, and (1H, 13C, and 119Sn) NMR. The structures of complexes 1-4 were confirmed by X-ray diffraction. Three"inward E-type"complexes 1-3 were formed by the inward orientation of two substituted salicylaldehyde acylhydrazone chains of H4L and coordination with tin atoms. And two substituted salicylaldehyde acylhydrazone chains were oriented outward and coordinated with tin atoms to form an"outward E-type"complex 4. Complexes 1, 2, and 4 belong to the triclinic P1 space group and complex 3 belongs to the monoclinic P21/c space group. The central tin and the coordination atom form a five-coordinate distorted triangular bipyramids configuration. The fluorescence properties of the ligands and the complexes-chloroform solution showed that when free ligand m-Ph(CONH—N=CH(o-OH)PhNEt2)2 (H4L1) with weak fluorescence and ligand m-Ph(CONH—N=CH(o-OH)Ph(3, 5-t-2Bu))2 (H4L2) without fluorescence coordinated with phenyltin or cyclohexyltin, the chloroform solution of the complexes emitted strong fluorescence.
Four new organotin complexes based on m-phthaloyl bis(substituted salicylaldehyde acylhydrazone) (H4L), (SnR2)2L (1-4), were synthesized by solvothermal reaction of H4L with R32SnOH, or one-pot solvothermal reaction of m-phthaloyl hydrazide, 3-tert-butyl salicylaldehyde, and tricyclohexyltin hydroxide, where H4L=m-Ph (CONH—N=CH(o-OH)PhR1)2; R1=NEt2, R2=Ph (1); R1=3, 5-di-tert-butyl=3, 5-t-2Bu, R2=Ph (2); R1=3, 5-t-2Bu, R2=Cy (3); R1=3-tert-butyl=3-t-Bu, R2=Cy (4). And they were characterized by elemental analysis, IR, and (1H, 13C, and 119Sn) NMR. The structures of complexes 1-4 were confirmed by X-ray diffraction. Three"inward E-type"complexes 1-3 were formed by the inward orientation of two substituted salicylaldehyde acylhydrazone chains of H4L and coordination with tin atoms. And two substituted salicylaldehyde acylhydrazone chains were oriented outward and coordinated with tin atoms to form an"outward E-type"complex 4. Complexes 1, 2, and 4 belong to the triclinic P1 space group and complex 3 belongs to the monoclinic P21/c space group. The central tin and the coordination atom form a five-coordinate distorted triangular bipyramids configuration. The fluorescence properties of the ligands and the complexes-chloroform solution showed that when free ligand m-Ph(CONH—N=CH(o-OH)PhNEt2)2 (H4L1) with weak fluorescence and ligand m-Ph(CONH—N=CH(o-OH)Ph(3, 5-t-2Bu))2 (H4L2) without fluorescence coordinated with phenyltin or cyclohexyltin, the chloroform solution of the complexes emitted strong fluorescence.
2022, 38(6): 1180-1188
doi: 10.11862/CJIC.2022.121
Abstract:
In the presence of 2, 5-dimethoxyterephthalic acid (H2DTA), three 3D metal-organic frameworks, namely {[Zn(DTA)(1, 2, 4, 5-TIB)0.5]·1.5H2O}n (1), [Zn(DTA)(1, 4-BMIB)0.5(H2O)]n (2), and {[Zn(DTA)(1, 4-BMIN)]·H2O}n (3), have been synthesized by using imidazole derivatives 1, 2, 4, 5-tetra(1H-imidazol-1-yl)benzene (1, 2, 4, 5-TIB), 1, 4-bis(4-methyl-1H-imidazol-1-yl)benzene (1, 4-BMIB), and 1, 4-bis(4-methyl-1H-imidazol-1-yl)naphthalene (1, 4-BMIN) as ligands to react to zinc ions, respectively. Their structures and fluorescent properties were studied. Single crystal X-ray diffraction analysis reveals that all complexes belong to the monoclinic crystal system. Among them, complex 1 based on four-coordinated 1, 2, 4, 5-TIB is a four-connected framework with a point symbol of (62.84). Compared with complex 1, slim 1, 4-BMIB and 1, 4-BMIN ligands with low coordination numbers caused that complexes 2 and 3 are 2-fold interpenetration pcu-type and 3-fold interpenetration dia-type networks, respectively. Furthermore, the fluorescent properties of complexes 1-3 were also studied, and their emission spectra had a significant enhancement and blue shift compared to the emission peak of the ligands.
In the presence of 2, 5-dimethoxyterephthalic acid (H2DTA), three 3D metal-organic frameworks, namely {[Zn(DTA)(1, 2, 4, 5-TIB)0.5]·1.5H2O}n (1), [Zn(DTA)(1, 4-BMIB)0.5(H2O)]n (2), and {[Zn(DTA)(1, 4-BMIN)]·H2O}n (3), have been synthesized by using imidazole derivatives 1, 2, 4, 5-tetra(1H-imidazol-1-yl)benzene (1, 2, 4, 5-TIB), 1, 4-bis(4-methyl-1H-imidazol-1-yl)benzene (1, 4-BMIB), and 1, 4-bis(4-methyl-1H-imidazol-1-yl)naphthalene (1, 4-BMIN) as ligands to react to zinc ions, respectively. Their structures and fluorescent properties were studied. Single crystal X-ray diffraction analysis reveals that all complexes belong to the monoclinic crystal system. Among them, complex 1 based on four-coordinated 1, 2, 4, 5-TIB is a four-connected framework with a point symbol of (62.84). Compared with complex 1, slim 1, 4-BMIB and 1, 4-BMIN ligands with low coordination numbers caused that complexes 2 and 3 are 2-fold interpenetration pcu-type and 3-fold interpenetration dia-type networks, respectively. Furthermore, the fluorescent properties of complexes 1-3 were also studied, and their emission spectra had a significant enhancement and blue shift compared to the emission peak of the ligands.
2022, 38(6): 1189-1198
doi: 10.11862/CJIC.2022.116
Abstract:
In this work, based on the industrial refinery product of pitch, we have developed a simple method for the production of metal-free, nitrogen, and sulfur co-doping porous carbon nanosheets (NSPC). The obtained NSPC exhibited a high specific surface area (339 m2·g-1) and puissant adsorbability for sulfur fixation. At the same time, the co-doping of N and S can effectively improve the electrical conductivity of carbon nanomaterials, and further improve the adsorption and conversion reaction of lithium polysulfides (LIPSs). The NSPC/S electrode delivered superior cycling performance (762 mAh·g-1 at 0.6C after 200 cycles). This work represents a rapid and massive production of two-dimensional porous carbon materials with high content of N and S as the cathode for advanced lithium-sulfur batteries.
In this work, based on the industrial refinery product of pitch, we have developed a simple method for the production of metal-free, nitrogen, and sulfur co-doping porous carbon nanosheets (NSPC). The obtained NSPC exhibited a high specific surface area (339 m2·g-1) and puissant adsorbability for sulfur fixation. At the same time, the co-doping of N and S can effectively improve the electrical conductivity of carbon nanomaterials, and further improve the adsorption and conversion reaction of lithium polysulfides (LIPSs). The NSPC/S electrode delivered superior cycling performance (762 mAh·g-1 at 0.6C after 200 cycles). This work represents a rapid and massive production of two-dimensional porous carbon materials with high content of N and S as the cathode for advanced lithium-sulfur batteries.
2022, 38(6): 1199-1208
doi: 10.11862/CJIC.2022.117
Abstract:
By using different anions, three Cu-Tb metal complexes, namely [Cu2(vanophen)2TbCl2(MeOH)2]Cl· 3MeOH (1), [Cu2(vanophen)2TbCl2(MeOH)2](TCNQ)1.5·2MeOH (2), and [Cu2(vanophen)2Tb2(N3)6]·2MeOH (3), based on the compartmental Schiff-base ligand H2vanophen (H2vanophen=N, N′-bis(2-oxy-3-methoxybenzylidene)-1, 2-phenylenediamine, TCNQ=7, 7, 8, 8-tetracyanoquinodimethane) have been synthesized and characterized structurally and magnetically. Except for the different charge-balancing anions, complexes 1 and 2 have a very similar trinuclear [CuTbCu] structure, where the Cu(Ⅱ) ions are in the [N2O4] coordination pockets of the ligands, while the Tb(Ⅲ) ion is coordinated by all or some of the oxygen atoms from the [O4] pocket of the ligands. The charge-balancing anion is a Cl- ion in 1, while the positive charge is balanced by one TCNQ-0.5 radical and a half of the TCNQ- radical in 2. As for complex 3, it has a tetranuclear [CuTb]2 structure, where two [CuTb] units are bridged by end-end and end-on azides. Magnetic studies revealed that both 1 and 2 are field-induced SMMs while 3 is a zero-field SMM. The energy barriers of 1 and 3 were estimated to be (11.1±0.3) cm-1 and (20.2±0.3) cm-1, respectively. As for complex 2, its energy barrier was lower than that of 1, which might be due to the weak magnetic interaction between the [CuTbCu] unit and the paramagnetic radical anions.
By using different anions, three Cu-Tb metal complexes, namely [Cu2(vanophen)2TbCl2(MeOH)2]Cl· 3MeOH (1), [Cu2(vanophen)2TbCl2(MeOH)2](TCNQ)1.5·2MeOH (2), and [Cu2(vanophen)2Tb2(N3)6]·2MeOH (3), based on the compartmental Schiff-base ligand H2vanophen (H2vanophen=N, N′-bis(2-oxy-3-methoxybenzylidene)-1, 2-phenylenediamine, TCNQ=7, 7, 8, 8-tetracyanoquinodimethane) have been synthesized and characterized structurally and magnetically. Except for the different charge-balancing anions, complexes 1 and 2 have a very similar trinuclear [CuTbCu] structure, where the Cu(Ⅱ) ions are in the [N2O4] coordination pockets of the ligands, while the Tb(Ⅲ) ion is coordinated by all or some of the oxygen atoms from the [O4] pocket of the ligands. The charge-balancing anion is a Cl- ion in 1, while the positive charge is balanced by one TCNQ-0.5 radical and a half of the TCNQ- radical in 2. As for complex 3, it has a tetranuclear [CuTb]2 structure, where two [CuTb] units are bridged by end-end and end-on azides. Magnetic studies revealed that both 1 and 2 are field-induced SMMs while 3 is a zero-field SMM. The energy barriers of 1 and 3 were estimated to be (11.1±0.3) cm-1 and (20.2±0.3) cm-1, respectively. As for complex 2, its energy barrier was lower than that of 1, which might be due to the weak magnetic interaction between the [CuTbCu] unit and the paramagnetic radical anions.
