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2019 Volume 35 Issue 9
2019, 35(9): 1521-1534
doi: 10.11862/CJIC.2019.186
Abstract:
Semi-artificial photosynthetic system based on inorganic material-microbe hybrid is a research system developed in the aspects of natural and artificial photosynthesis research to a certain stage, in order to overcome their respective defects and achieve complementary advantages of microbe and inorganic material. The main advantage of this system is the conjunction of catalytic selectivity of microbe and photo-response property of inorganic materials, which aim to solve the problem of poor catalytic selectivity of artificial photosynthetic system. At present, microbe-based semi-artificial photosynthesis can be achieved by photocatalyst-microbe hybrids and electrode-microbe hybrids. In this review, semi-artificial photosynthesis based on inorganic material-microbe hybrid is systematically expounded from semi-artificial water oxidation, semi-artificial photosynthetic reduction and material-microbe interface. The research progress of semi-artificial photosynthetic system based on electrode-microbe hybrids is emphatically introduced. The current situation of semi-artificial photosynthesis based on inorganic material-microbe hybrids has been analyzed and summarized, and the prospects of this field are outlooked.
Semi-artificial photosynthetic system based on inorganic material-microbe hybrid is a research system developed in the aspects of natural and artificial photosynthesis research to a certain stage, in order to overcome their respective defects and achieve complementary advantages of microbe and inorganic material. The main advantage of this system is the conjunction of catalytic selectivity of microbe and photo-response property of inorganic materials, which aim to solve the problem of poor catalytic selectivity of artificial photosynthetic system. At present, microbe-based semi-artificial photosynthesis can be achieved by photocatalyst-microbe hybrids and electrode-microbe hybrids. In this review, semi-artificial photosynthesis based on inorganic material-microbe hybrid is systematically expounded from semi-artificial water oxidation, semi-artificial photosynthetic reduction and material-microbe interface. The research progress of semi-artificial photosynthetic system based on electrode-microbe hybrids is emphatically introduced. The current situation of semi-artificial photosynthesis based on inorganic material-microbe hybrids has been analyzed and summarized, and the prospects of this field are outlooked.
2019, 35(9): 1535-1550
doi: 10.11862/CJIC.2019.188
Abstract:
With the rapid development of secondary battery technology, lithium ion batteries (LIBs) have become an important energy storage device today. However, lithium resources in the earth's crust are limited and lithium-based compounds are expensive. Hence, researchers are looking for the alternatives of LIBs. Not only sodium-ion batteries (SIBs) works at a similar mechanism as LIBs, but also sodium is more abundant and more homogeneous on the earth, and its price is lower, making SIBs are one most promising secondary battery system to replace LIBs. Unfortunately, the shortcomings including the larger Na+ radius and the higher irreversibility of electrode reactions lead to a very large difficulty to achieve high-performance SIBs. Therefore, it is still a big challenge to develop advanced electrode materials for SIBs. Amongst all types of cathode materials, Na superionic conductor (NASICON) type materials are one class of compounds with ultrafast Na+ transformation and high structural stability during the successive de-sodiation/sodiation processes, suggesting its obvious application possibility for actual SIBs. In this review, we firstly introduced the crystal structure of NASICON materials, and then summarized the research progresses on the NASICON-type cathode for SIBs from the point of view of types and numbers of transition metal and the introduction of anions, and further analyzed the main problems and challenges of NASICON-type materials.
With the rapid development of secondary battery technology, lithium ion batteries (LIBs) have become an important energy storage device today. However, lithium resources in the earth's crust are limited and lithium-based compounds are expensive. Hence, researchers are looking for the alternatives of LIBs. Not only sodium-ion batteries (SIBs) works at a similar mechanism as LIBs, but also sodium is more abundant and more homogeneous on the earth, and its price is lower, making SIBs are one most promising secondary battery system to replace LIBs. Unfortunately, the shortcomings including the larger Na+ radius and the higher irreversibility of electrode reactions lead to a very large difficulty to achieve high-performance SIBs. Therefore, it is still a big challenge to develop advanced electrode materials for SIBs. Amongst all types of cathode materials, Na superionic conductor (NASICON) type materials are one class of compounds with ultrafast Na+ transformation and high structural stability during the successive de-sodiation/sodiation processes, suggesting its obvious application possibility for actual SIBs. In this review, we firstly introduced the crystal structure of NASICON materials, and then summarized the research progresses on the NASICON-type cathode for SIBs from the point of view of types and numbers of transition metal and the introduction of anions, and further analyzed the main problems and challenges of NASICON-type materials.
2019, 35(9): 1551-1560
doi: 10.11862/CJIC.2019.161
Abstract:
The direct Z-scheme Zn2SnO4-xNx/ZnO1-yNy heterojunction photocatalyst was successfully prepared via a microwave-assisted solvothermal method. N atoms were introduced in to the lattices of Zn2SnO4 and ZnO by replacing O atoms to form Zn2SnO4-xNx and ZnO1-yNy units, resulting in the formation of N impurity levels at the top of valence band (VB). The transformation from Ⅰ-type to Ⅱ-type, and then to Z-scheme heterojunction of Zn2SnO4-xNx/ZnO1-yNy was attributed to the rearrangement of interface charge distribution induced by the different work functions and the construction of build-in electron field. The photocatalytic activity of heterojunction photocatalyst was evaluated by the photo-degradation of RhB under UV light irradiation. The degradation rate of RhB over Zn2SnO4-xNx/ZnO1-yNy heterojunction photocatalyst was 1.40~1.43 times higher than that of two pure Zn2SnO4-xNx samples. Methylene blue, methyl orange and salicylic acid could be degraded over Zn2SnO4-xNx/ZnO1-yNy heterojunction photocatalyst, which also exhibited good cyclic stability. The high photocatalytic activity of Zn2SnO4-xNx/ZnO1-yNy heterojunction photocatalyst was ascribed to the synergistic effects between Z-scheme heterojunction and double impurity levels due to the enhanced redox ability and improved separation efficiency of photoinduced charge carriers.
The direct Z-scheme Zn2SnO4-xNx/ZnO1-yNy heterojunction photocatalyst was successfully prepared via a microwave-assisted solvothermal method. N atoms were introduced in to the lattices of Zn2SnO4 and ZnO by replacing O atoms to form Zn2SnO4-xNx and ZnO1-yNy units, resulting in the formation of N impurity levels at the top of valence band (VB). The transformation from Ⅰ-type to Ⅱ-type, and then to Z-scheme heterojunction of Zn2SnO4-xNx/ZnO1-yNy was attributed to the rearrangement of interface charge distribution induced by the different work functions and the construction of build-in electron field. The photocatalytic activity of heterojunction photocatalyst was evaluated by the photo-degradation of RhB under UV light irradiation. The degradation rate of RhB over Zn2SnO4-xNx/ZnO1-yNy heterojunction photocatalyst was 1.40~1.43 times higher than that of two pure Zn2SnO4-xNx samples. Methylene blue, methyl orange and salicylic acid could be degraded over Zn2SnO4-xNx/ZnO1-yNy heterojunction photocatalyst, which also exhibited good cyclic stability. The high photocatalytic activity of Zn2SnO4-xNx/ZnO1-yNy heterojunction photocatalyst was ascribed to the synergistic effects between Z-scheme heterojunction and double impurity levels due to the enhanced redox ability and improved separation efficiency of photoinduced charge carriers.
2019, 35(9): 1561-1569
doi: 10.11862/CJIC.2019.192
Abstract:
Li1.184[Ni0.15Mn0.516Co0.15]O2-modified carbon nanotubes network composite (CNT@LMR) cathode materials were synthesized by a novel strategy that adopted these technologies of compressed air crush, high pressure micro-fluidization dispersion and spray dehydration. The microstructures and morphologies were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffractometer (XRD) and Raman spectroscopy, which indicated that CNTs conductive network were uniformly distributed on the surface of lithium-manganese-rich (LMR) and existed between primary particles from LMR inside. The novel network structure built on Li-rich cathode material not only took advantage of CNTs as conductive additives, but also combined the characteristic of CNTs network acts as a surface modification layer. The electrochemical tests demonstrated that CNTs modified LMR electrode had higher rate capability and cycle stability. For example, CNT@LMR had discharge specific capacity of 141.4 mAh·g-1 at 5C-rate, compared to the capacity of pristine LMR (76.6 mAh·g-1) and composite LMR electrode with CNT conductive additives (110.7 mAh·g-1). After 100 cycle tests at 1C-rate, the capacity retention of CNTs modified LMR was 87.2% compared to pristine LMR of 77.8%. According to electrochemical impedance spectroscopy (EIS) with different cycle tests, CNTs network structure on the surface of LMR improved electrode/electrolyte interface reaction, restrained solid electrolyte interphase (SEI) film growth and polarization of LMR electrode, and CNTs conductive network inside LMR reduced resistance and accelerated charge transfer process for primary particle.
Li1.184[Ni0.15Mn0.516Co0.15]O2-modified carbon nanotubes network composite (CNT@LMR) cathode materials were synthesized by a novel strategy that adopted these technologies of compressed air crush, high pressure micro-fluidization dispersion and spray dehydration. The microstructures and morphologies were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffractometer (XRD) and Raman spectroscopy, which indicated that CNTs conductive network were uniformly distributed on the surface of lithium-manganese-rich (LMR) and existed between primary particles from LMR inside. The novel network structure built on Li-rich cathode material not only took advantage of CNTs as conductive additives, but also combined the characteristic of CNTs network acts as a surface modification layer. The electrochemical tests demonstrated that CNTs modified LMR electrode had higher rate capability and cycle stability. For example, CNT@LMR had discharge specific capacity of 141.4 mAh·g-1 at 5C-rate, compared to the capacity of pristine LMR (76.6 mAh·g-1) and composite LMR electrode with CNT conductive additives (110.7 mAh·g-1). After 100 cycle tests at 1C-rate, the capacity retention of CNTs modified LMR was 87.2% compared to pristine LMR of 77.8%. According to electrochemical impedance spectroscopy (EIS) with different cycle tests, CNTs network structure on the surface of LMR improved electrode/electrolyte interface reaction, restrained solid electrolyte interphase (SEI) film growth and polarization of LMR electrode, and CNTs conductive network inside LMR reduced resistance and accelerated charge transfer process for primary particle.
2019, 35(9): 1579-1585
doi: 10.11862/CJIC.2019.193
Abstract:
Two complexes, [Ag(H2btc)(bpy)] (1) and[Cd(Hbtc)(bpy)(H2O)2]n (2) (H3btc=1, 2, 4-benzenetricarboxylic acid, bpy=2, 2'-bipyridine), were synthesized under pH-controlled hydrothermal conditions and characterized by X-ray single crystal diffraction, IR spectra, thermal gravimetric analysis (TGA) and fluorescence spectroscopy. The results show that complex 1 is a zero-dimensional mononuclear small molecule structure, and 2 is a one-dimensional chain structure. Fluorescence studies showed that both complexes have fluorescent properties.
Two complexes, [Ag(H2btc)(bpy)] (1) and[Cd(Hbtc)(bpy)(H2O)2]n (2) (H3btc=1, 2, 4-benzenetricarboxylic acid, bpy=2, 2'-bipyridine), were synthesized under pH-controlled hydrothermal conditions and characterized by X-ray single crystal diffraction, IR spectra, thermal gravimetric analysis (TGA) and fluorescence spectroscopy. The results show that complex 1 is a zero-dimensional mononuclear small molecule structure, and 2 is a one-dimensional chain structure. Fluorescence studies showed that both complexes have fluorescent properties.
2019, 35(9): 1586-1592
doi: 10.11862/CJIC.2019.191
Abstract:
Two new 1D chain luminescence metal-organic coordination polymers[Zn(H2BBP)(BDC)]n (1) and {[Cd2(H2BBP)2(BDC)2]·3H2O}n (2) were prepared by hydrothermal method using the rigid 2, 6-bis(benzimidazolyl)pyridine (H2BBP) and ancillary ligand terephthalic acid (BDC) as the ligands. The metal ion in compound 1 was coordinated with the carboxyl group of the BDC ligand by the monodentate mode, while the metal ion in the compound 2 was monodentate-bidentate heterozygous coordination, which results in the different angles of 1D zigzag chain in compound 1 and compound 2. 4-Nitrophenol (4-NP) detection of compounds 1 and 2 was carried out by fluorescence spectroscopy. The results show that 4-NP has strong fluorescence quenching effect on compounds 1 and 2, and the detection limit of compound 1 could be as low as 30.96 μg·L-1.
Two new 1D chain luminescence metal-organic coordination polymers[Zn(H2BBP)(BDC)]n (1) and {[Cd2(H2BBP)2(BDC)2]·3H2O}n (2) were prepared by hydrothermal method using the rigid 2, 6-bis(benzimidazolyl)pyridine (H2BBP) and ancillary ligand terephthalic acid (BDC) as the ligands. The metal ion in compound 1 was coordinated with the carboxyl group of the BDC ligand by the monodentate mode, while the metal ion in the compound 2 was monodentate-bidentate heterozygous coordination, which results in the different angles of 1D zigzag chain in compound 1 and compound 2. 4-Nitrophenol (4-NP) detection of compounds 1 and 2 was carried out by fluorescence spectroscopy. The results show that 4-NP has strong fluorescence quenching effect on compounds 1 and 2, and the detection limit of compound 1 could be as low as 30.96 μg·L-1.
2019, 35(9): 1593-1601
doi: 10.11862/CJIC.2019.179
Abstract:
Cs2SiF6:Mn4+ red phosphor was synthesized by a soft chemistry method. The phase and morphology of the samples were characterized by powder X-ray diffraction (XRD) and scanning electron microscopy(SEM). The fluorescence spectra with different Mn4+ doping concentrations, temperature-dependence emission spectra, lumine-scence lifetime and quantum efficiency of the samples were measured to evaluate their performance. At the same time, the LED devices were encapsulated and the photoelectric performance was tested. The results reveal that the as-synthesized pure phase red phosphor Cs2SiF6:Mn4+ has an irregular morphology. In the excitation spectra, the broadband excitation peaks at 360 and 460 nm are attributed to 4A2g→4T1g and 4A2g→4T2g transitions, respectively. In the emission spectra, the narrow-band emission peak at 630 nm can be attributed to 2Eg→4A2g transition. When the temperature rose from 25 to 150℃, the luminescence intensity remained basically unchanged. The luminescence intensity at 150℃ was 100.03% of that at 25℃. The luminescence life of samples with different Mn4+ doping concentrations are above 8.0 ms. The quantum efficiency of the optimal sample Cs2SiF6:0.06Mn4+ is 88%. In addition, in the devices encapsulated by using Cs2SiF6:0.06Mn4+ as the red component, when the addition amount of Cs2SiF6:0.06Mn4+ is 24% (mass fraction), the CIE coordinate is (0.411 3, 0.412 9), color temperature CCT=3 899 K, color rendering index Ra=88, R9=84.2, and the luminous efficiency is 123.84 lm·W-1. Meanwhile, the devices emit warm white light.
Cs2SiF6:Mn4+ red phosphor was synthesized by a soft chemistry method. The phase and morphology of the samples were characterized by powder X-ray diffraction (XRD) and scanning electron microscopy(SEM). The fluorescence spectra with different Mn4+ doping concentrations, temperature-dependence emission spectra, lumine-scence lifetime and quantum efficiency of the samples were measured to evaluate their performance. At the same time, the LED devices were encapsulated and the photoelectric performance was tested. The results reveal that the as-synthesized pure phase red phosphor Cs2SiF6:Mn4+ has an irregular morphology. In the excitation spectra, the broadband excitation peaks at 360 and 460 nm are attributed to 4A2g→4T1g and 4A2g→4T2g transitions, respectively. In the emission spectra, the narrow-band emission peak at 630 nm can be attributed to 2Eg→4A2g transition. When the temperature rose from 25 to 150℃, the luminescence intensity remained basically unchanged. The luminescence intensity at 150℃ was 100.03% of that at 25℃. The luminescence life of samples with different Mn4+ doping concentrations are above 8.0 ms. The quantum efficiency of the optimal sample Cs2SiF6:0.06Mn4+ is 88%. In addition, in the devices encapsulated by using Cs2SiF6:0.06Mn4+ as the red component, when the addition amount of Cs2SiF6:0.06Mn4+ is 24% (mass fraction), the CIE coordinate is (0.411 3, 0.412 9), color temperature CCT=3 899 K, color rendering index Ra=88, R9=84.2, and the luminous efficiency is 123.84 lm·W-1. Meanwhile, the devices emit warm white light.
2019, 35(9): 1602-1608
doi: 10.11862/CJIC.2019.180
Abstract:
Two nickel(Ⅱ) complexes[Ni(Lss)(Py)] (1) and[Ni2(Lrr)2(4, 4'-bipy)] (2) having different hydrazone ligand, where H2Lss is 2-thiophenecarboxylic acid (2-hydroxly-5-nitro-benzylidene)-hydrazide, H2Lrr is 2-thiophenecar-boxylic acid (2-hydroxly-5-bromo-benzylidene)-hydrazide, have been hydrothermally synthesized in presence of pyridine or 4, 4'-bipyridine as co-ligand and characterized by elemental analysis, FT-IR and electronic spectra. The structures of complexes have been accomplished by single crystal X-ray diffraction which results confirmed that the crystal of 1 belongs to the orthorhombic system, space group Pbca and the crystal of 2 belongs to the monoclinic system, space group P21/c. The antitumor activities in vitro of ligands and complexes were tested by MTT method, which results show that 1 and 2 have strong in vitro antitumor activity against human acute promyelocytic leukemia cells HL-60. The quantum chemical calculation for the complex 2 was performed by means of Gaussian 09 program at B3LYP/6-31G(d) basis set.
Two nickel(Ⅱ) complexes[Ni(Lss)(Py)] (1) and[Ni2(Lrr)2(4, 4'-bipy)] (2) having different hydrazone ligand, where H2Lss is 2-thiophenecarboxylic acid (2-hydroxly-5-nitro-benzylidene)-hydrazide, H2Lrr is 2-thiophenecar-boxylic acid (2-hydroxly-5-bromo-benzylidene)-hydrazide, have been hydrothermally synthesized in presence of pyridine or 4, 4'-bipyridine as co-ligand and characterized by elemental analysis, FT-IR and electronic spectra. The structures of complexes have been accomplished by single crystal X-ray diffraction which results confirmed that the crystal of 1 belongs to the orthorhombic system, space group Pbca and the crystal of 2 belongs to the monoclinic system, space group P21/c. The antitumor activities in vitro of ligands and complexes were tested by MTT method, which results show that 1 and 2 have strong in vitro antitumor activity against human acute promyelocytic leukemia cells HL-60. The quantum chemical calculation for the complex 2 was performed by means of Gaussian 09 program at B3LYP/6-31G(d) basis set.
2019, 35(9): 1609-1618
doi: 10.11862/CJIC.2019.197
Abstract:
The geometric structures, energetics and electronic structures of[UO2(dNMP)(H2O)3]2+ (dNMP=deoxy-nucleotide monophosphate) in aqueous phase have been studied using density functional theory (DFT) method M06-2X with RLC ECP and ECP60MWB-SEG basis sets. Solvent effects of water was simulated by the polarized continuum model. The results showed that the most stable coordination uranyl ions formed by P=O bond of the phosphate group in dNMP, except the dTMP coordination ion. The bond lengths of U=O in four coordination uranyl ions were almost the same, but the coordination bond lengths were significantly different. The deoxyadenosine monophosphate (dAMP) coordination ion had the maximum binding energy among all the coordination ions, however, the coordinated dAMP possessed the smallest deformation energy. Concerning the differences in the calculation results of the two basis sets, the U=O bond lengths calculated by the ECP60MWB-SEG basis set were slightly longer than those obtained by the RLC ECP basis set, while the lengths of the coordination bonds showed opposite tendency. Additionally, the binding energy values calculated at the ECP60MWB-SEG basis set level were more negative than the RLC ECP basis set. The stretching vibrational frequencies of the U=O and P=O bonds exhibited a general red-shift, and the stretching vibrational frequencies of dAMP coordination ion decreased significantly. The topological analysis of electron density indicated that the coordination bond showed ionic character. It revealed that the charge transfer was from ligands to uranyl ion during the coordination process, and the maximum number of charge transferred by ligands in the dAMP coordination ion. Moreover, the molecular orbital composition demonstrated that the high-lying occupied molecular orbitals were actually contributed by π orbital of dNMP ligands, while the 5f atomic orbitals of uranium center mainly contributed to the low-lying unoccupied molecular orbitals. The frontier orbitals energy gap of deoxyguanosine monophosphate (dGMP) coordination ion was much smaller than any other coordination ions.
The geometric structures, energetics and electronic structures of[UO2(dNMP)(H2O)3]2+ (dNMP=deoxy-nucleotide monophosphate) in aqueous phase have been studied using density functional theory (DFT) method M06-2X with RLC ECP and ECP60MWB-SEG basis sets. Solvent effects of water was simulated by the polarized continuum model. The results showed that the most stable coordination uranyl ions formed by P=O bond of the phosphate group in dNMP, except the dTMP coordination ion. The bond lengths of U=O in four coordination uranyl ions were almost the same, but the coordination bond lengths were significantly different. The deoxyadenosine monophosphate (dAMP) coordination ion had the maximum binding energy among all the coordination ions, however, the coordinated dAMP possessed the smallest deformation energy. Concerning the differences in the calculation results of the two basis sets, the U=O bond lengths calculated by the ECP60MWB-SEG basis set were slightly longer than those obtained by the RLC ECP basis set, while the lengths of the coordination bonds showed opposite tendency. Additionally, the binding energy values calculated at the ECP60MWB-SEG basis set level were more negative than the RLC ECP basis set. The stretching vibrational frequencies of the U=O and P=O bonds exhibited a general red-shift, and the stretching vibrational frequencies of dAMP coordination ion decreased significantly. The topological analysis of electron density indicated that the coordination bond showed ionic character. It revealed that the charge transfer was from ligands to uranyl ion during the coordination process, and the maximum number of charge transferred by ligands in the dAMP coordination ion. Moreover, the molecular orbital composition demonstrated that the high-lying occupied molecular orbitals were actually contributed by π orbital of dNMP ligands, while the 5f atomic orbitals of uranium center mainly contributed to the low-lying unoccupied molecular orbitals. The frontier orbitals energy gap of deoxyguanosine monophosphate (dGMP) coordination ion was much smaller than any other coordination ions.
2019, 35(9): 1619-1622
doi: 10.11862/CJIC.2019.181
Abstract:
A new catalytic method for benzonitrile hydration in the absence of solvent was developed by using palladium acetate and phenylarsonic acid (molar ratio nPd:nAs=3:2) as catalyst, which exhibited high catalytic activity (space-time yield (STY)=186 mol·kg-1·h-1) and recyclability. Moreover, the product can be isolated as pure crystals and filtered from the reaction mixture after the reaction system cooling to low temperature (0℃), and the product was characterized by 1H NMR, 13C NMR and FT-IR.
A new catalytic method for benzonitrile hydration in the absence of solvent was developed by using palladium acetate and phenylarsonic acid (molar ratio nPd:nAs=3:2) as catalyst, which exhibited high catalytic activity (space-time yield (STY)=186 mol·kg-1·h-1) and recyclability. Moreover, the product can be isolated as pure crystals and filtered from the reaction mixture after the reaction system cooling to low temperature (0℃), and the product was characterized by 1H NMR, 13C NMR and FT-IR.
2019, 35(9): 1623-1634
doi: 10.11862/CJIC.2019.203
Abstract:
The disadvantage of the traditional hydrothermal method was the poor repeatability. Therefore, the conclusions of the influence of various parameters on the morphology of rare earth doped NaYF4 prepared by the traditional hydrothermal method reported by different research groups in the literature were different. In order to clarify the effects of hydrothermal parameters on the structure and morphology of rare earth doped NaYF4, Dy3+ doped NaYF4 phosphors were prepared by microwave hydrothermal method with good reproducibility and controllability. The effects of various parameters on the structure, morphology and luminescence of the products were systematically studied. The reproducible NaYF4:Dy3+ samples were rapidly prepared by microwave-assisted hydrothermal method. The effects of reaction parameters on the crystal phase, morphology and luminescence properties of NaYF4:Dy3+ phosphors were investigated. The results show that the microwave hydrothermal reaction time don't affect the crystal phase, morphology and spectral properties of the as-prepared phosphors. The increase of Dy3+ concentration do not change the crystal phase and morphology of the samples, but the luminescence intensity changes. The trends of luminescence intensity first increased and then decreased. The maximum luminescence intensity was obtained when the Dy3+ concentration was 1%(n/n). The electric multipole interaction index obtained according to the specific theoretical basis was 6. It is shown that the interaction between Dy3+ is dipole-dipole interaction. The effects of the type and amounts of surfactant on the NaYF4:Dy3+ crystal phase were investigated. It was observed when Na3Cit·2H2O and CTAB were used as surfactants, hexagonal phase NaYF4:Dy3+ phosphors were prepared. The amounts of Na3Cit·2H2O and CTAB were increased and the crystal phase of the sample was not changed. When EDTA-2Na was used as the surfactant, the transition from the hexagonal phase to the cubic phase crystal phase occurred as the amounts of the EDTA-2Na increased. As the amounts of surfactants continue to increase, the size of the sample decreased. Under the excitation of 350 nm, Dy3+ emission peaks appeared. The blue light emission peak centered at 479 nm, which corresponds to the 4F9/2→6H15/2 transition of Dy3+. The green light emission peak centered at 572 nm, which corresponds to the 4F9/2→6H13/2 transition of Dy3+.
The disadvantage of the traditional hydrothermal method was the poor repeatability. Therefore, the conclusions of the influence of various parameters on the morphology of rare earth doped NaYF4 prepared by the traditional hydrothermal method reported by different research groups in the literature were different. In order to clarify the effects of hydrothermal parameters on the structure and morphology of rare earth doped NaYF4, Dy3+ doped NaYF4 phosphors were prepared by microwave hydrothermal method with good reproducibility and controllability. The effects of various parameters on the structure, morphology and luminescence of the products were systematically studied. The reproducible NaYF4:Dy3+ samples were rapidly prepared by microwave-assisted hydrothermal method. The effects of reaction parameters on the crystal phase, morphology and luminescence properties of NaYF4:Dy3+ phosphors were investigated. The results show that the microwave hydrothermal reaction time don't affect the crystal phase, morphology and spectral properties of the as-prepared phosphors. The increase of Dy3+ concentration do not change the crystal phase and morphology of the samples, but the luminescence intensity changes. The trends of luminescence intensity first increased and then decreased. The maximum luminescence intensity was obtained when the Dy3+ concentration was 1%(n/n). The electric multipole interaction index obtained according to the specific theoretical basis was 6. It is shown that the interaction between Dy3+ is dipole-dipole interaction. The effects of the type and amounts of surfactant on the NaYF4:Dy3+ crystal phase were investigated. It was observed when Na3Cit·2H2O and CTAB were used as surfactants, hexagonal phase NaYF4:Dy3+ phosphors were prepared. The amounts of Na3Cit·2H2O and CTAB were increased and the crystal phase of the sample was not changed. When EDTA-2Na was used as the surfactant, the transition from the hexagonal phase to the cubic phase crystal phase occurred as the amounts of the EDTA-2Na increased. As the amounts of surfactants continue to increase, the size of the sample decreased. Under the excitation of 350 nm, Dy3+ emission peaks appeared. The blue light emission peak centered at 479 nm, which corresponds to the 4F9/2→6H15/2 transition of Dy3+. The green light emission peak centered at 572 nm, which corresponds to the 4F9/2→6H13/2 transition of Dy3+.
2019, 35(9): 1635-1641
doi: 10.11862/CJIC.2019.196
Abstract:
Double-shell nanocage CoS/NiCo2S4 was prepared by ion erosion and chemical vapor deposition using ZIF-67. The supercapacitor based on CoS/NiCo2S4 exhibited high specific capacitance and stability, due to its high specific surface area (98 m2·g-1), abundant interconnected channel (4 nm pole diameter), and stable cavity skeleton. The three-electrode cell based on CoS/NiCo2S4/Ni foam maintained 76.6% initial capacitance at 3 A·g-1 current density after 9 000 cycles. The cell gained a specific capacitance of 1 230 F·g-1 at 1 A·g-1 due to increasing active sites and rapid electron/ion transports for Faradaic reactions. The results can reflect the superior electrochemical performance of double-shell nanocage CoS/NiCo2S4 on specific capacitance and cycling stability. The supercapacitor was assembled by CoS/NiCo2S4/Ni foam, active carbon electrode and KOH/polyvinyl alcohol gel electrolyte. The device retention was 74.8% at a current density of 3 A·g-1 after 7 000 cycles. The device also achieved an energy density of 16.5 Wh·kg-1 at a high power density of 7 056 W·kg-1. Even at a power density of 702 W·kg-1, a high energy density of 31.6 Wh·kg-1 can be obtained. The asymmetric device exhibited excellent energy density, power density and cycle stability. In a practical application testing, two series-connected solid-state supercapacitors provided stable electrical energy, enabling the LEDs to be successfully illuminated.
Double-shell nanocage CoS/NiCo2S4 was prepared by ion erosion and chemical vapor deposition using ZIF-67. The supercapacitor based on CoS/NiCo2S4 exhibited high specific capacitance and stability, due to its high specific surface area (98 m2·g-1), abundant interconnected channel (4 nm pole diameter), and stable cavity skeleton. The three-electrode cell based on CoS/NiCo2S4/Ni foam maintained 76.6% initial capacitance at 3 A·g-1 current density after 9 000 cycles. The cell gained a specific capacitance of 1 230 F·g-1 at 1 A·g-1 due to increasing active sites and rapid electron/ion transports for Faradaic reactions. The results can reflect the superior electrochemical performance of double-shell nanocage CoS/NiCo2S4 on specific capacitance and cycling stability. The supercapacitor was assembled by CoS/NiCo2S4/Ni foam, active carbon electrode and KOH/polyvinyl alcohol gel electrolyte. The device retention was 74.8% at a current density of 3 A·g-1 after 7 000 cycles. The device also achieved an energy density of 16.5 Wh·kg-1 at a high power density of 7 056 W·kg-1. Even at a power density of 702 W·kg-1, a high energy density of 31.6 Wh·kg-1 can be obtained. The asymmetric device exhibited excellent energy density, power density and cycle stability. In a practical application testing, two series-connected solid-state supercapacitors provided stable electrical energy, enabling the LEDs to be successfully illuminated.
2019, 35(9): 1570-1578
doi: 10.11862/CJIC.2019.176
Abstract:
Three cyano-bridged Fe2Ni chain compounds were synthesized via the reaction of tetracyanometallate building block and pyridine ligands with different steric hindrance. Compounds {[Fe(bpy)(CN)4]2[Ni(bp)2]·2H2O}n (1) (bpy=2, 2'-bipyridine; bp=4-phenylpyridine), {[Fe(bpy)(CN)4]2[Ni(papy)2]·H2O}n (2) (papy=4-(phenyldiazenyl)pyridine) and {[Fe(bpy)(CN)4]2[Ni(azp)]·4H2O}n (3) (azp=1, 2-di(pyridin-4-yl)diazene) all show double-zigzag chain-like structures. Magnetic study indicates that compounds 1~3 all show intrachain ferromagnetic interactions. Alternating current susceptibility measurements demonstrated the single-chain magnet behavior of compound 1 with the relaxation energy barrier Ea/kB of 10.9 K.
Three cyano-bridged Fe2Ni chain compounds were synthesized via the reaction of tetracyanometallate building block and pyridine ligands with different steric hindrance. Compounds {[Fe(bpy)(CN)4]2[Ni(bp)2]·2H2O}n (1) (bpy=2, 2'-bipyridine; bp=4-phenylpyridine), {[Fe(bpy)(CN)4]2[Ni(papy)2]·H2O}n (2) (papy=4-(phenyldiazenyl)pyridine) and {[Fe(bpy)(CN)4]2[Ni(azp)]·4H2O}n (3) (azp=1, 2-di(pyridin-4-yl)diazene) all show double-zigzag chain-like structures. Magnetic study indicates that compounds 1~3 all show intrachain ferromagnetic interactions. Alternating current susceptibility measurements demonstrated the single-chain magnet behavior of compound 1 with the relaxation energy barrier Ea/kB of 10.9 K.
2019, 35(9): 1642-1650
doi: 10.11862/CJIC.2019.194
Abstract:
Three Cd(Ⅱ)/Co(Ⅱ)/Zn(Ⅱ) coordination complexes, formulated as[Cd(hbmb)0.5(pta)]n (1), [Co(hbmb)(1, 4-bdc)]n (2), {[Zn2(hbmb)1.5(bptc)(H2O)]·0.5hbmb·3H2O}n (3) (hbmb=1, 1'-(1, 6-hexane)bis-(2-methylbenzimidazole), H2pta=homophthalic acid, 1, 4-H2bdc=1, 4-benzenedicarboxylic acid, H4bptc=3, 3', 4, 4'-benzophenone tetracar-boxylic acid), have been obtained by hydrothermal/solvothermal reactions. Complex 1 is a flat 4-connected 2D topology net with point symbol of (44·62), complex 2 features a undulated 2D network with point symbol of (42·6)(42·63·8), while complex 3 (3, 4, 4)-connected 3-fold interpenetrating network with a vertex symbol of (42·62·82)(4·62)(4·64·8) topology. Crystal data are monoclinic, space group, P21/c, a=0.758 32(15) nm, b=1.452 8(3) nm, c=1.911 3(5) nm, β=112.26(3)°, Z=4 for 1; and monoclinic, space group, P21/n, a=1.090 8(2) nm, b=1.873 1(4) nm, c=1.301 9(3) nm, β=91.09(3)°, Z=4 for 2; and triclinic, space group, P1, a=1.119 6(2) nm, b=1.481 2(3) nm, c=1.926 6(4) nm, α=89.72(3)°, β=87.65(3)°, γ=68.28(3)°, Z=2 for 3.
Three Cd(Ⅱ)/Co(Ⅱ)/Zn(Ⅱ) coordination complexes, formulated as[Cd(hbmb)0.5(pta)]n (1), [Co(hbmb)(1, 4-bdc)]n (2), {[Zn2(hbmb)1.5(bptc)(H2O)]·0.5hbmb·3H2O}n (3) (hbmb=1, 1'-(1, 6-hexane)bis-(2-methylbenzimidazole), H2pta=homophthalic acid, 1, 4-H2bdc=1, 4-benzenedicarboxylic acid, H4bptc=3, 3', 4, 4'-benzophenone tetracar-boxylic acid), have been obtained by hydrothermal/solvothermal reactions. Complex 1 is a flat 4-connected 2D topology net with point symbol of (44·62), complex 2 features a undulated 2D network with point symbol of (42·6)(42·63·8), while complex 3 (3, 4, 4)-connected 3-fold interpenetrating network with a vertex symbol of (42·62·82)(4·62)(4·64·8) topology. Crystal data are monoclinic, space group, P21/c, a=0.758 32(15) nm, b=1.452 8(3) nm, c=1.911 3(5) nm, β=112.26(3)°, Z=4 for 1; and monoclinic, space group, P21/n, a=1.090 8(2) nm, b=1.873 1(4) nm, c=1.301 9(3) nm, β=91.09(3)°, Z=4 for 2; and triclinic, space group, P1, a=1.119 6(2) nm, b=1.481 2(3) nm, c=1.926 6(4) nm, α=89.72(3)°, β=87.65(3)°, γ=68.28(3)°, Z=2 for 3.
2019, 35(9): 1651-1658
doi: 10.11862/CJIC.2019.164
Abstract:
Two new mixed-valence heptanuclear manganese complexes, [Na2MnⅡMn6ⅢO2(L)6(N3)4(CH3COO)2]·4DMF (1) and[Na2MnⅡMn6ⅢO2(L)6(SCN)4(CH3COO)2]·2DMF (2) (H2L=3-ethoxy-6-(((2-hydroxyethyl)imino)methyl) phenol), were synthesized by treating the Schiff-base ligand with Mn(OAc)2·4H2O, and characterized by elemental analysis, IR spectra, thermogravimetric analyses and X-ray single crystal diffraction. X-ray single crystal diffraction analysis reveals that 1 and 2 have a similar new mixed-valence heptanuclear structure. The magnetic measurements indicate that 1 and 2 exhibit the antiferromagnetic interactions.
Two new mixed-valence heptanuclear manganese complexes, [Na2MnⅡMn6ⅢO2(L)6(N3)4(CH3COO)2]·4DMF (1) and[Na2MnⅡMn6ⅢO2(L)6(SCN)4(CH3COO)2]·2DMF (2) (H2L=3-ethoxy-6-(((2-hydroxyethyl)imino)methyl) phenol), were synthesized by treating the Schiff-base ligand with Mn(OAc)2·4H2O, and characterized by elemental analysis, IR spectra, thermogravimetric analyses and X-ray single crystal diffraction. X-ray single crystal diffraction analysis reveals that 1 and 2 have a similar new mixed-valence heptanuclear structure. The magnetic measurements indicate that 1 and 2 exhibit the antiferromagnetic interactions.
2019, 35(9): 1659-1664
doi: 10.11862/CJIC.2019.202
Abstract:
CePO4-6LaPO4@xSiO2:Eu3+ phosphors were synthesized by sol-gel method and high temperature solid state method. The structure and luminescence property of the phosphors were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), energy dispersive spectra (EDS), infrared spectra (IR), excitation spectra and emission spectra. The results of XRD and EDS confirmed target product, which was made up of crystalline state LaPO4, CePO4 and amorphous state SiO2; TEM showed that the morphology of the sample was irregular and CePO4-6LaPO4@4SiO2:Eu3+ phosphor formed core-shell structure; HRTEM image clearly showed the formation of lattice fringes; IR study was consistent with the XRD and EDS study. The fluorescence spectra showed that under excitation with 466 nm, the CePO4-6LaPO4@xSiO2:Eu3+ phosphor gave a strongest red emission at the 615 nm that belongs to the 5D0→7F2 transition of Eu3+.
CePO4-6LaPO4@xSiO2:Eu3+ phosphors were synthesized by sol-gel method and high temperature solid state method. The structure and luminescence property of the phosphors were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), energy dispersive spectra (EDS), infrared spectra (IR), excitation spectra and emission spectra. The results of XRD and EDS confirmed target product, which was made up of crystalline state LaPO4, CePO4 and amorphous state SiO2; TEM showed that the morphology of the sample was irregular and CePO4-6LaPO4@4SiO2:Eu3+ phosphor formed core-shell structure; HRTEM image clearly showed the formation of lattice fringes; IR study was consistent with the XRD and EDS study. The fluorescence spectra showed that under excitation with 466 nm, the CePO4-6LaPO4@xSiO2:Eu3+ phosphor gave a strongest red emission at the 615 nm that belongs to the 5D0→7F2 transition of Eu3+.
2019, 35(9): 1665-1677
doi: 10.11862/CJIC.2019.199
Abstract:
Intrinsically poor reactivity restricts hematite (α-Fe2O3) from heterogeneous Fenton systems. Usually, metal ion doping, noble metal loading, and compounding with other compounds to enhance their catalytic activity are necessary, making them complex, expensive, and difficult to control. Here a surface-electronic-state-modulation-based concept applied to hematite is presented. This concept enables hematite with dual reaction sites as highly reactive and reusable Fenton-like catalysts for efficient catalytic oxidation of recalcitrant organics, via activation of H2O2 and without any extra energy input. The rhodamine B degradation rate constants for α-Fe2O3-x-330/H2O2 systems were 0.834 h-1, when pH=4, and have a much wider pH working window (pH=2~10) than traditional Fenton systems. Meanwhile, the used catalyst can be easily recovered by magnetic separation. Oxygen vacancy and Fe(Ⅱ) on defective α-Fe2O3-x surfaces have been confirmed as the active sites for H2O2 activation, while the adjacent vacancy oxygens site adsorbs organic molecules and thus improves the Fenton-like catalytic performance. These findings may not only extend the environment applications of pure transition metal oxide but also stimulate new opportunities for the same as many other transition metal oxides by surface electronic-state modulation.
Intrinsically poor reactivity restricts hematite (α-Fe2O3) from heterogeneous Fenton systems. Usually, metal ion doping, noble metal loading, and compounding with other compounds to enhance their catalytic activity are necessary, making them complex, expensive, and difficult to control. Here a surface-electronic-state-modulation-based concept applied to hematite is presented. This concept enables hematite with dual reaction sites as highly reactive and reusable Fenton-like catalysts for efficient catalytic oxidation of recalcitrant organics, via activation of H2O2 and without any extra energy input. The rhodamine B degradation rate constants for α-Fe2O3-x-330/H2O2 systems were 0.834 h-1, when pH=4, and have a much wider pH working window (pH=2~10) than traditional Fenton systems. Meanwhile, the used catalyst can be easily recovered by magnetic separation. Oxygen vacancy and Fe(Ⅱ) on defective α-Fe2O3-x surfaces have been confirmed as the active sites for H2O2 activation, while the adjacent vacancy oxygens site adsorbs organic molecules and thus improves the Fenton-like catalytic performance. These findings may not only extend the environment applications of pure transition metal oxide but also stimulate new opportunities for the same as many other transition metal oxides by surface electronic-state modulation.
2019, 35(9): 1678-1686
doi: 10.11862/CJIC.2019.200
Abstract:
To improve the electrocatalytic activity of pristine graphite felt (GF) towards the V3+/V2+ redox couple and reduce the impact of the hydrogen evolution reaction (HER) on battery performance, in this study, cadmium oxide (CdO) nanoparticles were loaded onto the surface of graphite felt fibers by the hydrothermal method to prepare a high-performance negative electrode of a VRFB. The results of scanning electron microscopy (SEM), X-ray diffraction (XRD) showed that CdO nanoparticles were uniformly loaded on the surface of graphite felt fibers; Linear sweep voltammetry (LSV), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) results indicated that the activity of HER was significantly inhibited by the presence of CdO. Furthermore, the electrochemical activity and reversibility of cadmium-doped graphite felt (CdO/GF) for the V3+/V2+ redox reaction were significantly improved, and the charge transfer resistance was also significantly reduced as compared with GF. In a single-cell test, compared to GF, the discharge capacity attenuation rate of CdO/GF significantly decreased, the voltage efficiency and energy efficiency of CdO/GF were enhanced by approximately 5% at a current density of 90 mA·cm-2. Moreover, the catalytic performance of CdO/GF showed good stability during constant current 100 charge-discharge tests.
To improve the electrocatalytic activity of pristine graphite felt (GF) towards the V3+/V2+ redox couple and reduce the impact of the hydrogen evolution reaction (HER) on battery performance, in this study, cadmium oxide (CdO) nanoparticles were loaded onto the surface of graphite felt fibers by the hydrothermal method to prepare a high-performance negative electrode of a VRFB. The results of scanning electron microscopy (SEM), X-ray diffraction (XRD) showed that CdO nanoparticles were uniformly loaded on the surface of graphite felt fibers; Linear sweep voltammetry (LSV), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) results indicated that the activity of HER was significantly inhibited by the presence of CdO. Furthermore, the electrochemical activity and reversibility of cadmium-doped graphite felt (CdO/GF) for the V3+/V2+ redox reaction were significantly improved, and the charge transfer resistance was also significantly reduced as compared with GF. In a single-cell test, compared to GF, the discharge capacity attenuation rate of CdO/GF significantly decreased, the voltage efficiency and energy efficiency of CdO/GF were enhanced by approximately 5% at a current density of 90 mA·cm-2. Moreover, the catalytic performance of CdO/GF showed good stability during constant current 100 charge-discharge tests.
2019, 35(9): 1687-1697
doi: 10.11862/CJIC.2019.201
Abstract:
A new tri-hydroxyl corrole, 10-(4-hydroxyphenyl)-5, 15-bis(4-(2-hydroxyethyl) amino-2, 3, 5, 6-tetrafluoro-phenyl) corrole (1), and its gallium complex (1-Ga), were prepared. Interactions between these two corrole derivatives and calf thymus DNA were investigated by multiple spectroscopic methods, viscosity experiments and molecular docking simulation, which reveal that 1 and 1-Ga interact with calf thymus DNA via outside binding mode. Agarose gel electrophoretic experimental results demonstrated that 1 and 1-Ga exhibit excellent photonu-clease activity. Both compounds demonstrated high photocytotoxic activity against human lung cancer cells A549, hepatoma cell HepG2 and human breast cancer cell MCF-7. After light irradiation, they might induce HepG2 cells apoptosis via ROS-mediated mitochondrial pathways. Furthermore, 1-Ga could arrest the tumor cell cycle at G2/M phases.
A new tri-hydroxyl corrole, 10-(4-hydroxyphenyl)-5, 15-bis(4-(2-hydroxyethyl) amino-2, 3, 5, 6-tetrafluoro-phenyl) corrole (1), and its gallium complex (1-Ga), were prepared. Interactions between these two corrole derivatives and calf thymus DNA were investigated by multiple spectroscopic methods, viscosity experiments and molecular docking simulation, which reveal that 1 and 1-Ga interact with calf thymus DNA via outside binding mode. Agarose gel electrophoretic experimental results demonstrated that 1 and 1-Ga exhibit excellent photonu-clease activity. Both compounds demonstrated high photocytotoxic activity against human lung cancer cells A549, hepatoma cell HepG2 and human breast cancer cell MCF-7. After light irradiation, they might induce HepG2 cells apoptosis via ROS-mediated mitochondrial pathways. Furthermore, 1-Ga could arrest the tumor cell cycle at G2/M phases.
2019, 35(9): 1698-1704
doi: 10.11862/CJIC.2019.198
Abstract:
A simple and facile sol-gel method was used to fabricate novel uniform silica nanotubes and hollow spheres controllably in the same reaction system. The different reaction conditions were investigated, such as reaction time, addition and stirring rate of tetraethyl orthosilicate (TEOS) and the ratio of water and ethanol, which had important influence on the formation of the silica nanotubes with uniform morphologies. The formation process investigation of silica nanotubes discloses that ammonium citrate (AC) crystals have the thin pillar-like morphologies in the mixed solution including ethanol and water, which acts as an important template for the gradual aggradation of silica colloids on their surface to form the tubular structure. The silica hollow spheres have the similar formation mechanism to that of silica nanotubes with a little difference of using citric acid (CA) as a starting structure-directing agent.
A simple and facile sol-gel method was used to fabricate novel uniform silica nanotubes and hollow spheres controllably in the same reaction system. The different reaction conditions were investigated, such as reaction time, addition and stirring rate of tetraethyl orthosilicate (TEOS) and the ratio of water and ethanol, which had important influence on the formation of the silica nanotubes with uniform morphologies. The formation process investigation of silica nanotubes discloses that ammonium citrate (AC) crystals have the thin pillar-like morphologies in the mixed solution including ethanol and water, which acts as an important template for the gradual aggradation of silica colloids on their surface to form the tubular structure. The silica hollow spheres have the similar formation mechanism to that of silica nanotubes with a little difference of using citric acid (CA) as a starting structure-directing agent.
2019, 35(9): 1705-1711
doi: 10.11862/CJIC.2019.190
Abstract:
Zero dimensional dinuclear nickel(Ⅱ) coordination compound and 1D chain nickel(Ⅱ) coordination polymer, namely[Ni2(μ-HL)2(2, 2'-bipy)2(H2O)4]·6H2O (1) and {[Ni(μ-HL)(2, 2'-bipy)(H2O)2]·H2O}n (2), have been constructed hydrothermally using 2, 5-di(4-carboxylphenyl)nicotinic acid (H3L), 2, 2'-bipyridine (2, 2'-bipy), and nickel chloride at 120 or 160℃, respectively. Single-crystal X-ray diffraction analyses revealed that both complexes crystallize in the triclinic system, space group P1. Complex 1 discloses a discrete dimer structure, which is assembled to a 3D supramolecular framework through O-H…O/N hydrogen bond. Complex 2 has a chain structure. Structural differences between compounds 1 and 2 may be attributed to the different hydrothermal reaction temperature. Magnetic studies for complex 2 demonstrate an antiferromagnetic coupling between the adjacent Ni(Ⅱ) centers.
Zero dimensional dinuclear nickel(Ⅱ) coordination compound and 1D chain nickel(Ⅱ) coordination polymer, namely[Ni2(μ-HL)2(2, 2'-bipy)2(H2O)4]·6H2O (1) and {[Ni(μ-HL)(2, 2'-bipy)(H2O)2]·H2O}n (2), have been constructed hydrothermally using 2, 5-di(4-carboxylphenyl)nicotinic acid (H3L), 2, 2'-bipyridine (2, 2'-bipy), and nickel chloride at 120 or 160℃, respectively. Single-crystal X-ray diffraction analyses revealed that both complexes crystallize in the triclinic system, space group P1. Complex 1 discloses a discrete dimer structure, which is assembled to a 3D supramolecular framework through O-H…O/N hydrogen bond. Complex 2 has a chain structure. Structural differences between compounds 1 and 2 may be attributed to the different hydrothermal reaction temperature. Magnetic studies for complex 2 demonstrate an antiferromagnetic coupling between the adjacent Ni(Ⅱ) centers.
