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2019 Volume 35 Issue 12
2019, 35(12): 2193-2199
doi: 10.11862/CJIC.2019.270
Abstract:
In the same reaction conditions, the isotactic metal-doped[CoxCd1-x(pypymba)2]n (0 ≤ x ≤ 1) (compounds 1~5) were synthesized based on ligand (Hpypymba=4-((3-(pyrazin-2-yl)-1H-pyrazol-1-yl)-methyl)benzoic acid) and a transition metal ion (Co(Ⅱ), Cd(Ⅱ)). The structure and morphology were characterized by powder X-ray diffraction (PXRD) and UV-visible scanning. The obtained MOFs were used as a catalyst carrier to carry Ag ions to carry out a reduction reaction of 4-nitrophenol. The results showed that the Compound 1 which contained Co2+ was the better catalyst carrier. As the proportion of Cd2+ in compounds increased, the reaction rate decreased, and even the reaction has a certain inhibitory effect. The maximum loading of the MOFs for Ag was 47%(w/w), and 96% of the catalytic efficiency after 4 cycles.
In the same reaction conditions, the isotactic metal-doped[CoxCd1-x(pypymba)2]n (0 ≤ x ≤ 1) (compounds 1~5) were synthesized based on ligand (Hpypymba=4-((3-(pyrazin-2-yl)-1H-pyrazol-1-yl)-methyl)benzoic acid) and a transition metal ion (Co(Ⅱ), Cd(Ⅱ)). The structure and morphology were characterized by powder X-ray diffraction (PXRD) and UV-visible scanning. The obtained MOFs were used as a catalyst carrier to carry Ag ions to carry out a reduction reaction of 4-nitrophenol. The results showed that the Compound 1 which contained Co2+ was the better catalyst carrier. As the proportion of Cd2+ in compounds increased, the reaction rate decreased, and even the reaction has a certain inhibitory effect. The maximum loading of the MOFs for Ag was 47%(w/w), and 96% of the catalytic efficiency after 4 cycles.
2019, 35(12): 2337-2345
doi: 10.11862/CJIC.2019.274
Abstract:
Two antenna molecules zinc porphyrin P2, P3 were prepared, and these antenna molecules have been successfully used in DSSCs (dye-sensitized solar cells) through supramolecular self-assembly. Compared with traditional D-π-A structure dyes, this strategy shows obvious advantages. This method can avoid complex synthesis steps, the light-harvesting ability of dyes can be improved and charge recombination can be reduced by adjusting the antenna molecules and anchoring groups. When 4-pyrid-4-ylbenzoic acid (A) was used as the anchoring group, after supramolecular self-assembly, the device of A-P2 displayed a PCE (power conversion efficiency) of 1.68%, and the Voc was 526 mV, the Jsc was 5.39 mA·cm-2. This indicates that the supramolecular self-assembly strategy has been successfully applied in DSSC. The device of A-P3 displayed the PCE of 0.79%, which is mainly due to the lower amount of dye loading. In addition, the optical properties, electrochemical properties, photovoltaic performance were also studied.
Two antenna molecules zinc porphyrin P2, P3 were prepared, and these antenna molecules have been successfully used in DSSCs (dye-sensitized solar cells) through supramolecular self-assembly. Compared with traditional D-π-A structure dyes, this strategy shows obvious advantages. This method can avoid complex synthesis steps, the light-harvesting ability of dyes can be improved and charge recombination can be reduced by adjusting the antenna molecules and anchoring groups. When 4-pyrid-4-ylbenzoic acid (A) was used as the anchoring group, after supramolecular self-assembly, the device of A-P2 displayed a PCE (power conversion efficiency) of 1.68%, and the Voc was 526 mV, the Jsc was 5.39 mA·cm-2. This indicates that the supramolecular self-assembly strategy has been successfully applied in DSSC. The device of A-P3 displayed the PCE of 0.79%, which is mainly due to the lower amount of dye loading. In addition, the optical properties, electrochemical properties, photovoltaic performance were also studied.
2019, 35(12): 2346-2354
doi: 10.11862/CJIC.2019.265
Abstract:
Two pairs of novel homochiral coordination polymers (HCPs), formulated as {[Zn((R)-CBA)(1, 3-DIMB)]·H2O}n (1-D), {[Zn((S)-CBA)(1, 3-DIMB)]·H2O}n (1-L), [Zn2((R)-CBA)2(1, 4-BMIP)]n (2-D) and[Zn2((S)-CBA)2(1, 4-BMIP)2]n (2-L) have been synthesized using lactic acid ligands ((R)-H2CBA and (S)-H2CBA) and Zn2+ under hydrothermal conditions. Crystallographic analysis reveals that all the complexes contain chiral helical chains, which are constructed by CBA2- ligands and Zn(Ⅱ) ions. Meanwhile, the rigid auxiliary ligands 1, 3-DIMB and 1, 4-BMIP play important roles in structural diversity. Some physical characteristics, including thermal stabilities, solid-state circular dichroism (CD), and photoluminescent properties, were also carried out. The results show that the semi-rigid lactic acid ligand can used to effectively synthesize HCPs with a helical structure.
Two pairs of novel homochiral coordination polymers (HCPs), formulated as {[Zn((R)-CBA)(1, 3-DIMB)]·H2O}n (1-D), {[Zn((S)-CBA)(1, 3-DIMB)]·H2O}n (1-L), [Zn2((R)-CBA)2(1, 4-BMIP)]n (2-D) and[Zn2((S)-CBA)2(1, 4-BMIP)2]n (2-L) have been synthesized using lactic acid ligands ((R)-H2CBA and (S)-H2CBA) and Zn2+ under hydrothermal conditions. Crystallographic analysis reveals that all the complexes contain chiral helical chains, which are constructed by CBA2- ligands and Zn(Ⅱ) ions. Meanwhile, the rigid auxiliary ligands 1, 3-DIMB and 1, 4-BMIP play important roles in structural diversity. Some physical characteristics, including thermal stabilities, solid-state circular dichroism (CD), and photoluminescent properties, were also carried out. The results show that the semi-rigid lactic acid ligand can used to effectively synthesize HCPs with a helical structure.
2019, 35(12): 2355-2363
doi: 10.11862/CJIC.2019.271
Abstract:
Three coordination polymers, {[Zn(ca)(iimb)]·0.75H2O}n (1), {[Cd(ca)(iimb)(H2O)]·0.75H2O}n (2) and {[Zn(ca)(bpe)0.5(H2O)]·H2O}n (3) (H2ca=citraconic acid, iimb=1-(1-imidazolyl)-4-(imidazol-1-ylmethyl)benzene, bpe=1, 2-di(4-pyridyl)ethylene), were synthesized hydrothermally and measured structurally by single crystal X-ray diffraction, infrared spectroscopy(IR) and elemental analysis. Complex 1 displays a 2D reticular layer containing 1D metal-carboxylate chains. 2 features a 1D quasi-trapezoidal shape chain structure containing carboxylate-bridged dinuclear structures. Complex 3 shows a two-dimensional wave layer. The three-dimensional supramolecular structures of 2 and 3 are formed by abundant H-bond interactions; nevertheless, 3D supramolecular structure of 1 is formed through weak van der Waals force. Thermogravimetric analyses (TGA), powder X-ray diffractions (PXRD) and fluorescence properties for complexes 1~3 were investigated. The solid state fluorescence spectra indicate that all emission spectra of three complexes 1~3 are similar with those of the corresponding auxiliary ligands. In addition, complex 3 exhibits good photocatalytic activity for methylene blue (MB) degradation in the presence of H2O2 under UV irradiation.
Three coordination polymers, {[Zn(ca)(iimb)]·0.75H2O}n (1), {[Cd(ca)(iimb)(H2O)]·0.75H2O}n (2) and {[Zn(ca)(bpe)0.5(H2O)]·H2O}n (3) (H2ca=citraconic acid, iimb=1-(1-imidazolyl)-4-(imidazol-1-ylmethyl)benzene, bpe=1, 2-di(4-pyridyl)ethylene), were synthesized hydrothermally and measured structurally by single crystal X-ray diffraction, infrared spectroscopy(IR) and elemental analysis. Complex 1 displays a 2D reticular layer containing 1D metal-carboxylate chains. 2 features a 1D quasi-trapezoidal shape chain structure containing carboxylate-bridged dinuclear structures. Complex 3 shows a two-dimensional wave layer. The three-dimensional supramolecular structures of 2 and 3 are formed by abundant H-bond interactions; nevertheless, 3D supramolecular structure of 1 is formed through weak van der Waals force. Thermogravimetric analyses (TGA), powder X-ray diffractions (PXRD) and fluorescence properties for complexes 1~3 were investigated. The solid state fluorescence spectra indicate that all emission spectra of three complexes 1~3 are similar with those of the corresponding auxiliary ligands. In addition, complex 3 exhibits good photocatalytic activity for methylene blue (MB) degradation in the presence of H2O2 under UV irradiation.
2019, 35(12): 2364-2372
doi: 10.11862/CJIC.2019.268
Abstract:
We design a photo-thermoelectric nanogenerator (PTENG) based on a flexible film of molybdenum disulfide (MoS2) dispersed in a pyroelectric polymer. The transition-metal dichalcogenide as thin-layered nanosheets can harvest the incident near-infrared (NIR) light and convert it into thermal energy. The pyroelectric polymer subsequently transduced the thermal energy collected by the inorganic nanosheets into electric energy. Under NIR irradiation, the PTENG can generate voltage and photocurrent instantly, and the output kept at high level for a long time. High thermoelectric conversion coefficient was obtained, which arised from efficient coupling between photothermal and pyroelectric effects. Theoretical simulation distinguished the contribution of MoS2 in the polymer nanocomposite. MoS2 significantly increased the temperature change rate in pyroelectric polymer films, leading to enhanced photoelectric response in the device.
We design a photo-thermoelectric nanogenerator (PTENG) based on a flexible film of molybdenum disulfide (MoS2) dispersed in a pyroelectric polymer. The transition-metal dichalcogenide as thin-layered nanosheets can harvest the incident near-infrared (NIR) light and convert it into thermal energy. The pyroelectric polymer subsequently transduced the thermal energy collected by the inorganic nanosheets into electric energy. Under NIR irradiation, the PTENG can generate voltage and photocurrent instantly, and the output kept at high level for a long time. High thermoelectric conversion coefficient was obtained, which arised from efficient coupling between photothermal and pyroelectric effects. Theoretical simulation distinguished the contribution of MoS2 in the polymer nanocomposite. MoS2 significantly increased the temperature change rate in pyroelectric polymer films, leading to enhanced photoelectric response in the device.
2019, 35(12): 2200-2208
doi: 10.11862/CJIC.2019.269
Abstract:
Four dinuclear benzyltin complexes were synthesized by microwave "one-pot synthesis", namely {[C4H3S(O)C=N-N=C(Me)COO](PhCH2)2Sn(MeOH)}2 (C1), {[C4H3S(O)C=N-N=C(Me)COO](p-Cl-C6H4CH2)2Sn(MeOH)}2 (C2), {[C4H3S(O)C=N-N=C(PhCH2)COO](PhCH2)2Sn(MeOH)}2 (C3), {[C4H3S(O)C=N-N=C(PhCH2)COO](p-Cl-C6H4CH2)2Sn(MeOH)}2 (C4). The complexes C1~C4 were characterized by IR, 1H NMR, 13C NMR119Sn NMR spectra, elemental analysis, HRMS and the crystal structures were determined by X-ray diffraction. The four complexes are all binuclear molecules, and there was a Sn2O2 four-membered ring in the middle of the molecule. The central tin atom and the coordinating atom form a seven-coordinated pentagonal bipyramid configuration. The thermogravimetric of the complexes C1~C4 were analyzed, and in vitro antitumor activities of the complexes were evaluated by MTT against three human cancer cell lines (H460, HepG2, MCF7). The results show that complex C2 is the best compound for inhibiting cancer cells in the four synthesized complexes.
Four dinuclear benzyltin complexes were synthesized by microwave "one-pot synthesis", namely {[C4H3S(O)C=N-N=C(Me)COO](PhCH2)2Sn(MeOH)}2 (C1), {[C4H3S(O)C=N-N=C(Me)COO](p-Cl-C6H4CH2)2Sn(MeOH)}2 (C2), {[C4H3S(O)C=N-N=C(PhCH2)COO](PhCH2)2Sn(MeOH)}2 (C3), {[C4H3S(O)C=N-N=C(PhCH2)COO](p-Cl-C6H4CH2)2Sn(MeOH)}2 (C4). The complexes C1~C4 were characterized by IR, 1H NMR, 13C NMR119Sn NMR spectra, elemental analysis, HRMS and the crystal structures were determined by X-ray diffraction. The four complexes are all binuclear molecules, and there was a Sn2O2 four-membered ring in the middle of the molecule. The central tin atom and the coordinating atom form a seven-coordinated pentagonal bipyramid configuration. The thermogravimetric of the complexes C1~C4 were analyzed, and in vitro antitumor activities of the complexes were evaluated by MTT against three human cancer cell lines (H460, HepG2, MCF7). The results show that complex C2 is the best compound for inhibiting cancer cells in the four synthesized complexes.
2019, 35(12): 2209-2216
doi: 10.11862/CJIC.2019.267
Abstract:
Three zinc complexes, namely[Zn(Lss)(phen)(DMF)] (1), {[Zn(HLdis)]2·2CH3OH}n (2) and[Zn(Baf)2]·CH3OH (3), formed from different acylhydrazone-type Schiff base ligands were synthesized by using different methods, and the compounds were characterized by IR, UV-Vis spectra and TGA. The X-ray diffraction analyses reveal that 1 and 3 crystallize in the triclinic space group P1 while 2 in monoclinic system space group P21/n. In 1 and 3, coordination number of the Zn(Ⅱ) is six, and the centric atom locate in a distorted octahedron geometry, while in 2 Zn(Ⅱ) is five-coordination in a distorted square-pyramidal geometry. The precursor of 3 is pyrazoline derivative with the formula C15H14N2O3 (Pzl) crystallizing in monoclinic system space group P21/c. Due to the coordination of Zn(Ⅱ) causing the intramolecular rearrangement of Pzl, the ring open product HBaf in the form of an acylhydrazone structure coordinates with Zn(Ⅱ) to form complex 3.
Three zinc complexes, namely[Zn(Lss)(phen)(DMF)] (1), {[Zn(HLdis)]2·2CH3OH}n (2) and[Zn(Baf)2]·CH3OH (3), formed from different acylhydrazone-type Schiff base ligands were synthesized by using different methods, and the compounds were characterized by IR, UV-Vis spectra and TGA. The X-ray diffraction analyses reveal that 1 and 3 crystallize in the triclinic space group P1 while 2 in monoclinic system space group P21/n. In 1 and 3, coordination number of the Zn(Ⅱ) is six, and the centric atom locate in a distorted octahedron geometry, while in 2 Zn(Ⅱ) is five-coordination in a distorted square-pyramidal geometry. The precursor of 3 is pyrazoline derivative with the formula C15H14N2O3 (Pzl) crystallizing in monoclinic system space group P21/c. Due to the coordination of Zn(Ⅱ) causing the intramolecular rearrangement of Pzl, the ring open product HBaf in the form of an acylhydrazone structure coordinates with Zn(Ⅱ) to form complex 3.
2019, 35(12): 2217-2225
doi: 10.11862/CJIC.2019.226
Abstract:
The SnO2/TiO2 microspheres with hollow structure were synthesized by a simple template-free solvothermal method. The characterization results show that the size of SnO2/TiO2 microspheres is about 1 μm, and they are stacked together. The results of the synthesis process shows that the SnO2/TiO2 microspheres undergone from hollow, filled, split to a hollow structure again during formation process. Subsequently, the electrochemical performances of SnO2/TiO2 hollow microspheres are tested in lithium ion batteries. The initial discharge capacity of SnO2/TiO2 hollow microspheres can reach 1 484.9 mAh·g-1 at a current density of 0.1 A·g-1, with the coulombic effciency of 49.0%. After 600 cycles, the discharge capacity still reach 565.6 mAh·g-1. These results show that the as-prepared SnO2/TiO2 hollow microspheres have high capacity and cycle stability.
The SnO2/TiO2 microspheres with hollow structure were synthesized by a simple template-free solvothermal method. The characterization results show that the size of SnO2/TiO2 microspheres is about 1 μm, and they are stacked together. The results of the synthesis process shows that the SnO2/TiO2 microspheres undergone from hollow, filled, split to a hollow structure again during formation process. Subsequently, the electrochemical performances of SnO2/TiO2 hollow microspheres are tested in lithium ion batteries. The initial discharge capacity of SnO2/TiO2 hollow microspheres can reach 1 484.9 mAh·g-1 at a current density of 0.1 A·g-1, with the coulombic effciency of 49.0%. After 600 cycles, the discharge capacity still reach 565.6 mAh·g-1. These results show that the as-prepared SnO2/TiO2 hollow microspheres have high capacity and cycle stability.
2019, 35(12): 2226-2232
doi: 10.11862/CJIC.2019.256
Abstract:
Sr3Y(BO3)3:xTm3+, yDy3+ phosphors were prepared by high-temperature solid phase reaction. The phase structure, micromorphology, luminescence properties, energy transfer and CIE coordinates of the samples were investigated by XRD diffraction, SEM and fluorescence spectrophotometer. All results indicated that Sr3Y(BO3)3:xTm3+ phosphors emitted blue light under the excitation of 359 nm UV light and the Tm3+ concentration quenching point was x=0.08(n/n). In Sr3Y(BO3)3:0.08Tm3+, yDy3+ phosphors, with the Dy3+ doping concentration increasing, the Tm3+ luminescence intensity decreased; meanwhile, the Dy3+ luminescence intensity firstly increased and then decreased, and the critical quenching concentration of Dy3+ was y=0.1(n/n). The emitting color could be tuned by changing the doped Dy3+ concertration or the excitation wavelength. There is energy transfer between Tm3+-Dy3+ in the phosphors. When the doping concentration was y=0.15, the energy transfer efficiency was as high as 75.14%, and the energy transfer mechanism is electric dipole-dipole interaction.
Sr3Y(BO3)3:xTm3+, yDy3+ phosphors were prepared by high-temperature solid phase reaction. The phase structure, micromorphology, luminescence properties, energy transfer and CIE coordinates of the samples were investigated by XRD diffraction, SEM and fluorescence spectrophotometer. All results indicated that Sr3Y(BO3)3:xTm3+ phosphors emitted blue light under the excitation of 359 nm UV light and the Tm3+ concentration quenching point was x=0.08(n/n). In Sr3Y(BO3)3:0.08Tm3+, yDy3+ phosphors, with the Dy3+ doping concentration increasing, the Tm3+ luminescence intensity decreased; meanwhile, the Dy3+ luminescence intensity firstly increased and then decreased, and the critical quenching concentration of Dy3+ was y=0.1(n/n). The emitting color could be tuned by changing the doped Dy3+ concertration or the excitation wavelength. There is energy transfer between Tm3+-Dy3+ in the phosphors. When the doping concentration was y=0.15, the energy transfer efficiency was as high as 75.14%, and the energy transfer mechanism is electric dipole-dipole interaction.
2019, 35(12): 2233-2242
doi: 10.11862/CJIC.2019.275
Abstract:
C10H10Cl2Ti was selected as an additive to improve the hydrogen storage properties of the 6LiBH4-CaH2-3MgH2 sample, with optimum hydrogen storage performances by 5%(w/w) addition. The onset and ending temperatures for the dehydrogenation of the sample were 30 and 25℃, which were lower than those of the pristine sample, and its reversible hydrogen storage capacity was about 8.1%(w/w). The desorption rate of the C10H10Cl2Ti-doped sample was 1.78 times faster than that of the pristine sample in the isothermal dehydrogenation mode at 360℃. The apparent activation energy (Ea) of the two-step reaction was calculated to be 131.4 and 138.8 kJ·mol-1, which were 18.6% and 15.8% lower than the pristine sample, respectively. Further XPS analyses indicate that the multivalence state Ti compounds generate during thermal decomposition of C10H10Cl2Ti, which plays an important role to improve the hydrogen storage properties of the 6LiBH4-CaH2-3MgH2 system.
C10H10Cl2Ti was selected as an additive to improve the hydrogen storage properties of the 6LiBH4-CaH2-3MgH2 sample, with optimum hydrogen storage performances by 5%(w/w) addition. The onset and ending temperatures for the dehydrogenation of the sample were 30 and 25℃, which were lower than those of the pristine sample, and its reversible hydrogen storage capacity was about 8.1%(w/w). The desorption rate of the C10H10Cl2Ti-doped sample was 1.78 times faster than that of the pristine sample in the isothermal dehydrogenation mode at 360℃. The apparent activation energy (Ea) of the two-step reaction was calculated to be 131.4 and 138.8 kJ·mol-1, which were 18.6% and 15.8% lower than the pristine sample, respectively. Further XPS analyses indicate that the multivalence state Ti compounds generate during thermal decomposition of C10H10Cl2Ti, which plays an important role to improve the hydrogen storage properties of the 6LiBH4-CaH2-3MgH2 system.
2019, 35(12): 2243-2252
doi: 10.11862/CJIC.2019.272
Abstract:
The g-C3N4/SnO2 composite had been fabricated by the combination of hydrothermal method and thermal polymerization process in this paper. The crystal structures and morphology of various samples were characterized using XRD, SEM, TEM, FT-IR, and UV-Vis DRS. The results showed that the optical absorption edge of g-C3N4/SnO2 composites with co-effect of heterojunction had an obvious red shift to the longer wavelength in comparison with pure SnO2 and SnO2 nanoparticles were dispersing on the g-C3N4 surface well. The photocatalytic degradation properties of g-C3N4/SnO2 composites on rhodamine B (RhB) were remarkably improved under visible light irradiation, and the degradation rate of optimal 50%-g-C3N4/SnO2 composite was 3.78 times as great as that of pure g-C3N4.
The g-C3N4/SnO2 composite had been fabricated by the combination of hydrothermal method and thermal polymerization process in this paper. The crystal structures and morphology of various samples were characterized using XRD, SEM, TEM, FT-IR, and UV-Vis DRS. The results showed that the optical absorption edge of g-C3N4/SnO2 composites with co-effect of heterojunction had an obvious red shift to the longer wavelength in comparison with pure SnO2 and SnO2 nanoparticles were dispersing on the g-C3N4 surface well. The photocatalytic degradation properties of g-C3N4/SnO2 composites on rhodamine B (RhB) were remarkably improved under visible light irradiation, and the degradation rate of optimal 50%-g-C3N4/SnO2 composite was 3.78 times as great as that of pure g-C3N4.
2019, 35(12): 2253-2259
doi: 10.11862/CJIC.2019.263
Abstract:
The plate-like high-silica ZSM-5 zeolite (nSiO2/nAl2O3>90) with uniform morphology was synthesized by hydrothermal method at a lower crystallization temperature (130℃) in the absence of organic amine and seed. The effects on ratio of the amount of substance of reactants on the synthesis of high-silica ZSM-5 zeolite were systematically investigated. The synthesized high-silica ZSM-5 zeolite was characterized by XRD, FT-IR, SEM, N2 adsorption/desorption and 29Si MAS NMR techniques. Results confirmed that the synthesized ZSM-5 zeolite (nC2H5OH/nSiO2=2.8, nNa2O/nSiO2=0.14, nSiO2/nAl2O3=150) exhibited high crystallinity of the product. The specific surface area and micropore volume were 409 m2·g-1 and 0.14 cm3·g-1. 29Si MAS NMR analysis showed that the nSiO2/nAl2O3 was 96.4.
The plate-like high-silica ZSM-5 zeolite (nSiO2/nAl2O3>90) with uniform morphology was synthesized by hydrothermal method at a lower crystallization temperature (130℃) in the absence of organic amine and seed. The effects on ratio of the amount of substance of reactants on the synthesis of high-silica ZSM-5 zeolite were systematically investigated. The synthesized high-silica ZSM-5 zeolite was characterized by XRD, FT-IR, SEM, N2 adsorption/desorption and 29Si MAS NMR techniques. Results confirmed that the synthesized ZSM-5 zeolite (nC2H5OH/nSiO2=2.8, nNa2O/nSiO2=0.14, nSiO2/nAl2O3=150) exhibited high crystallinity of the product. The specific surface area and micropore volume were 409 m2·g-1 and 0.14 cm3·g-1. 29Si MAS NMR analysis showed that the nSiO2/nAl2O3 was 96.4.
2019, 35(12): 2260-2268
doi: 10.11862/CJIC.2019.254
Abstract:
Complexes 1~5 were synthesized by one-step reaction of 1-heptyl-1H-imidazole-2-carboxaldehyde(L1), 1-tetradecyl-1H-imidazole-2-carbaldehyde(L2), 1-hexadecyl-1H-imidazole-2-carbaldehyde(L3), 1-octadecyl-1H-imidazole-2-carboxaldehyde(L4), 1-eicosyl-1H-imidazole-2-carboxaldehyde(L5) with ferrous tetrafluoroborate and 1-phenylethylamine, respectively. The five complexes have been determined by IR spectra and elemental analysis. X-ray crystallography reveals that each unit in 1 contains one[Fe(L1)3]2+ cation and two BF4- anions. The iron(Ⅱ) center coordinates with six N donor atoms from three ligands to form a octahedral mononuclear compound with fac-configuration. The Fe(Ⅱ)-N bond distances indicate that the Fe(Ⅱ) sites of 1 are in low-spin state. As for[Fe(L1)3]2+, intramolecular π-π interactions are present between phenyl group and imidazole ring of an adjacent ligand, and then a supramolecular architectures are further formed by C-H…π interactions between alkyl chain and aromatic ring. Magnetic measurements reveal that 1 displays incomplete spin-crossover behaviour at 341 K, and 2 is a high-spin paramagnetic compound, while 3~5 show incomplete spin-crossover behaviour. The corresponding metallogels MOG2~MOG5 were formed by using complexes 2~5 with longer alkyl chains as gelator and cyclohexane as solvent. Scanning electron microscopy(SEM) images showed that the MOG2~MOG5 had 3D network pore structure. Reversible gel-sol transitions were found in MOG2~MOG5. Under the influence of heat and mechanical force, MOG2~MOG5 were rapidly converted to sol, which can be restored to gel after being stationary, showing good stimulation-response and self-healing ability.
Complexes 1~5 were synthesized by one-step reaction of 1-heptyl-1H-imidazole-2-carboxaldehyde(L1), 1-tetradecyl-1H-imidazole-2-carbaldehyde(L2), 1-hexadecyl-1H-imidazole-2-carbaldehyde(L3), 1-octadecyl-1H-imidazole-2-carboxaldehyde(L4), 1-eicosyl-1H-imidazole-2-carboxaldehyde(L5) with ferrous tetrafluoroborate and 1-phenylethylamine, respectively. The five complexes have been determined by IR spectra and elemental analysis. X-ray crystallography reveals that each unit in 1 contains one[Fe(L1)3]2+ cation and two BF4- anions. The iron(Ⅱ) center coordinates with six N donor atoms from three ligands to form a octahedral mononuclear compound with fac-configuration. The Fe(Ⅱ)-N bond distances indicate that the Fe(Ⅱ) sites of 1 are in low-spin state. As for[Fe(L1)3]2+, intramolecular π-π interactions are present between phenyl group and imidazole ring of an adjacent ligand, and then a supramolecular architectures are further formed by C-H…π interactions between alkyl chain and aromatic ring. Magnetic measurements reveal that 1 displays incomplete spin-crossover behaviour at 341 K, and 2 is a high-spin paramagnetic compound, while 3~5 show incomplete spin-crossover behaviour. The corresponding metallogels MOG2~MOG5 were formed by using complexes 2~5 with longer alkyl chains as gelator and cyclohexane as solvent. Scanning electron microscopy(SEM) images showed that the MOG2~MOG5 had 3D network pore structure. Reversible gel-sol transitions were found in MOG2~MOG5. Under the influence of heat and mechanical force, MOG2~MOG5 were rapidly converted to sol, which can be restored to gel after being stationary, showing good stimulation-response and self-healing ability.
2019, 35(12): 2269-2274
doi: 10.11862/CJIC.2019.220
Abstract:
Two novel cyclic Au(Ⅰ) complexes based on flexible bisimidazole-containing ligand, namely, [Au2(m-bitmb)2] [AuCl2]Cl·2CH3OH (1) and[Au2(m-bitmb)2] [AuCl2]2·2CH3CN (2) (m-bitmb=1, 3-bis(imidazol-1-ylmethyl)-2, 4, 6-trimethylbenzene), respectively, were obtained by diffusion method, which were further characterized by X-ray single crystal diffraction, elemental analysis, XRD and fluorescence spectroscopy. Complex 1 crystallizes in space group P2/c with a=0.895 6(9) nm, b=1.129 0(12) nm, c=2.166 3(2) nm, β=91.934(19)°, V=2.182 1(4) nm3, Z=2, Dc=2.012 g·cm-3, F(000)=1 248, the final R=0.036 6, wR=0.091 0. Complex 2 crystallizes in space group P1 with a=0.847 16(13) nm, b=1.168 82(17) nm, c=1.183 72(17) nm, α=97.132 0(10)°, β=96.872(2)°, γ=95.391(2)°, V=1.147 6(3) nm3, Z=1, Dc=2.275 g·cm-3, F(000)=728, the final R=0.038 1, wR=0.087 8. Both the title complexes have similar cyclic M2L2 structural units. The m-bitmb in 1 and 2 all adopt cis-conformation to coordinate to Au(Ⅰ) centers. The cyclic units in 1 and 2 are regularly arranged through π-π stacking interaction to form one-dimensional chain structures. Complex 1 has stronger π-π stacking effect than 2, but its aurophility is slightly weaker. The structural diversities of title complexes may be caused by the different solvents used in the synthesis process. Fluorescence results show that the aurophilic interactions in title complexes play important roles on their fluorescence properties.
Two novel cyclic Au(Ⅰ) complexes based on flexible bisimidazole-containing ligand, namely, [Au2(m-bitmb)2] [AuCl2]Cl·2CH3OH (1) and[Au2(m-bitmb)2] [AuCl2]2·2CH3CN (2) (m-bitmb=1, 3-bis(imidazol-1-ylmethyl)-2, 4, 6-trimethylbenzene), respectively, were obtained by diffusion method, which were further characterized by X-ray single crystal diffraction, elemental analysis, XRD and fluorescence spectroscopy. Complex 1 crystallizes in space group P2/c with a=0.895 6(9) nm, b=1.129 0(12) nm, c=2.166 3(2) nm, β=91.934(19)°, V=2.182 1(4) nm3, Z=2, Dc=2.012 g·cm-3, F(000)=1 248, the final R=0.036 6, wR=0.091 0. Complex 2 crystallizes in space group P1 with a=0.847 16(13) nm, b=1.168 82(17) nm, c=1.183 72(17) nm, α=97.132 0(10)°, β=96.872(2)°, γ=95.391(2)°, V=1.147 6(3) nm3, Z=1, Dc=2.275 g·cm-3, F(000)=728, the final R=0.038 1, wR=0.087 8. Both the title complexes have similar cyclic M2L2 structural units. The m-bitmb in 1 and 2 all adopt cis-conformation to coordinate to Au(Ⅰ) centers. The cyclic units in 1 and 2 are regularly arranged through π-π stacking interaction to form one-dimensional chain structures. Complex 1 has stronger π-π stacking effect than 2, but its aurophility is slightly weaker. The structural diversities of title complexes may be caused by the different solvents used in the synthesis process. Fluorescence results show that the aurophilic interactions in title complexes play important roles on their fluorescence properties.
2019, 35(12): 2275-2283
doi: 10.11862/CJIC.2019.264
Abstract:
Two low dimensional Mn(Ⅱ) complexes, (C4H7N2)[MnCl3(H2O)] (1) and[(C4H7N2)2] [MnBr4] (2), with different structures and optical properties have been synthesized by changing the types of imidazole ionic liquids species at room temperature. The complexes 1 and 2 have been characterized by single-crystal X-ray diffraction, photoluminescence, X-ray excitation emission spectrum, decay curve and thermogravimetric analysis. The X-ray diffraction results show that 1 crystallizes in the monoclinic space group P21/n, and the central Mn(Ⅱ) has an octahedral configuration, and 2 crystallizes in the triclinic space group P1, and the central Mn(Ⅱ) has a tetrahedron configuration. Under the UV light (λex=370 nm), solid complexes 1 and 2 emitted deep-red and green emission, respectively. The photoluminescence decay times were 200.11 and 37.23 μs, respectively, and their quantum yield were 23.52% and 5.54%, respectively. Moreover, under the excitation of X-ray, they showed the better X-ray fluorescence performance.
Two low dimensional Mn(Ⅱ) complexes, (C4H7N2)[MnCl3(H2O)] (1) and[(C4H7N2)2] [MnBr4] (2), with different structures and optical properties have been synthesized by changing the types of imidazole ionic liquids species at room temperature. The complexes 1 and 2 have been characterized by single-crystal X-ray diffraction, photoluminescence, X-ray excitation emission spectrum, decay curve and thermogravimetric analysis. The X-ray diffraction results show that 1 crystallizes in the monoclinic space group P21/n, and the central Mn(Ⅱ) has an octahedral configuration, and 2 crystallizes in the triclinic space group P1, and the central Mn(Ⅱ) has a tetrahedron configuration. Under the UV light (λex=370 nm), solid complexes 1 and 2 emitted deep-red and green emission, respectively. The photoluminescence decay times were 200.11 and 37.23 μs, respectively, and their quantum yield were 23.52% and 5.54%, respectively. Moreover, under the excitation of X-ray, they showed the better X-ray fluorescence performance.
2019, 35(12): 2284-2290
doi: 10.11862/CJIC.2019.259
Abstract:
The hydrothermal method was taken to preparing uniform C-sphere from glucose as the C source, then using ethylene glycol as the solvent, and nickel acetate, magnesium acetate and cerium chloride were added successively. Finally, the Ce-Mg-Ni/C nano-composite for hydrogen storage was producing. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were employed to analyze the phase composition and morphology of the solvent-thermal synthesis the nano-composites. Hydrogen adsorption-desorption measurements were performed by an automatic controlled Sieverts. SEM analysis indicated that the pre-fabricated composites with atom radios of 2:1:2 and 23:4:7 presented a nano-scale structure in uniform C-sphere templates. The XRD analysis showed that Ce2MgNi2 and Ce23Mg4Ni7 have been formed as nano-composite with carbon, and the peaks of the second phase CeMg3 and CeNi3 were presented in XRD patterns. P-C-T (pressure-composition-temperature) test date revealed that the hydrogen adsorption capacity of Ce2MgNi2/C and Ce23Mg4Ni7/C composites reached 1.54% and 1.05%(w/w) at 50℃, respectively.
The hydrothermal method was taken to preparing uniform C-sphere from glucose as the C source, then using ethylene glycol as the solvent, and nickel acetate, magnesium acetate and cerium chloride were added successively. Finally, the Ce-Mg-Ni/C nano-composite for hydrogen storage was producing. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were employed to analyze the phase composition and morphology of the solvent-thermal synthesis the nano-composites. Hydrogen adsorption-desorption measurements were performed by an automatic controlled Sieverts. SEM analysis indicated that the pre-fabricated composites with atom radios of 2:1:2 and 23:4:7 presented a nano-scale structure in uniform C-sphere templates. The XRD analysis showed that Ce2MgNi2 and Ce23Mg4Ni7 have been formed as nano-composite with carbon, and the peaks of the second phase CeMg3 and CeNi3 were presented in XRD patterns. P-C-T (pressure-composition-temperature) test date revealed that the hydrogen adsorption capacity of Ce2MgNi2/C and Ce23Mg4Ni7/C composites reached 1.54% and 1.05%(w/w) at 50℃, respectively.
2019, 35(12): 2291-2300
doi: 10.11862/CJIC.2019.255
Abstract:
1.0Fe-PILC was prepared by ion-exchange method with Na-Mont. nCu-Fe-PILC with different copper loadings were prepared by ultrasonic impregnation method, and used for the selective catalytic reduction of NO by C3H6 under oxygen-rich conditions. The microstructure and physicochemical properties of the catalysts were characterized by N2 adsorption-desorption, XRD, UV-Vis, H2-TPR and Py-FTIR, and the catalytic reaction mechanism was further explained. The results showed that the introduction of Cu improved the activity of the medium and low temperature and the resistance to H2O and SO2, among which more than 69.8% NO conversion at below 300℃, above 99% NO conversion after 400℃ and good resistance to H2O and SO2 were achieved by 9Cu-Fe-PILC. XRD and N2 adsorption-desorption results indicated that the SCR activity of the catalysts was related to the adsorption capacity and the supported active components. UV-Vis studies showed that 9Cu-Fe-PILC got strong activity at the medium and low temperature, which was related to its more isolated Cu2+. The H2-TPR results showed that the nCu-Fe-PILC modified by Cu had a better redox ability at the medium and low temperature compared with 1.0Fe-PILC. The results of Py-FTIR indicated that the surface of nCu-Fe-PILC contained both Lewis acid and Brønsted acid. Lewis acid was the main factor affecting the activity of SCR.
1.0Fe-PILC was prepared by ion-exchange method with Na-Mont. nCu-Fe-PILC with different copper loadings were prepared by ultrasonic impregnation method, and used for the selective catalytic reduction of NO by C3H6 under oxygen-rich conditions. The microstructure and physicochemical properties of the catalysts were characterized by N2 adsorption-desorption, XRD, UV-Vis, H2-TPR and Py-FTIR, and the catalytic reaction mechanism was further explained. The results showed that the introduction of Cu improved the activity of the medium and low temperature and the resistance to H2O and SO2, among which more than 69.8% NO conversion at below 300℃, above 99% NO conversion after 400℃ and good resistance to H2O and SO2 were achieved by 9Cu-Fe-PILC. XRD and N2 adsorption-desorption results indicated that the SCR activity of the catalysts was related to the adsorption capacity and the supported active components. UV-Vis studies showed that 9Cu-Fe-PILC got strong activity at the medium and low temperature, which was related to its more isolated Cu2+. The H2-TPR results showed that the nCu-Fe-PILC modified by Cu had a better redox ability at the medium and low temperature compared with 1.0Fe-PILC. The results of Py-FTIR indicated that the surface of nCu-Fe-PILC contained both Lewis acid and Brønsted acid. Lewis acid was the main factor affecting the activity of SCR.
2019, 35(12): 2301-2310
doi: 10.11862/CJIC.2019.258
Abstract:
Nanoporous Ni, Co and Ni-Co alloys were prepared by rapid solidification combined with de-alloying. The surface of Ni-Co alloy was modified by RuO2. The phase analysis and morphology of porous materials were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM) and transmission electron microscope (TEM). The electrocatalytic hydrogen evolution performance of the porous electrode was tested by linear sweep voltammetry, multi-potential step, alternating current impedance and potentiostatic electrolysis. The results show that the Ni-Co/RuO2 composite electrode material has a hydrogen evolution overpotential of 180 mV at a current density of 50 mA·cm-2. The hydrogen evolution process was controlled by the Volmer-Heyrovsky step, and the exchange current density was 4.42 mA·cm-2. Compared with nanoporous Ni, nanoporous Co and nanoporous Ni-Co alloy, Ni-Co/RuO2 composite electrode had the lowest apparent activation energy during hydrogen evolution. After 10 h constant current electrolysis, the potential only increased by 20 mV, showing excellent hydrogen evolution stability.
Nanoporous Ni, Co and Ni-Co alloys were prepared by rapid solidification combined with de-alloying. The surface of Ni-Co alloy was modified by RuO2. The phase analysis and morphology of porous materials were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM) and transmission electron microscope (TEM). The electrocatalytic hydrogen evolution performance of the porous electrode was tested by linear sweep voltammetry, multi-potential step, alternating current impedance and potentiostatic electrolysis. The results show that the Ni-Co/RuO2 composite electrode material has a hydrogen evolution overpotential of 180 mV at a current density of 50 mA·cm-2. The hydrogen evolution process was controlled by the Volmer-Heyrovsky step, and the exchange current density was 4.42 mA·cm-2. Compared with nanoporous Ni, nanoporous Co and nanoporous Ni-Co alloy, Ni-Co/RuO2 composite electrode had the lowest apparent activation energy during hydrogen evolution. After 10 h constant current electrolysis, the potential only increased by 20 mV, showing excellent hydrogen evolution stability.
2019, 35(12): 2311-2317
doi: 10.11862/CJIC.2019.260
Abstract:
Dy3+/Tb3+ co-doped glass ceramics containing SrWO4 crystal were synthesized successfully by melt-crystallization method and luminescence properties were studied. The optimum heat treatment temperature and time were determined by differential scanning calorimetry (DSC), the precipitation of SrWO4 grains in the precursor glass was determined by X-ray diffraction (XRD) and combining with the transmittance curves, the optimum heat treatment system was determined at 710℃ for 1.5 h. When the concentration of Dy2O3 was 0.8%(n/n), the effect of Tb4O7 concentration on the luminescence properties of glass ceramic samples were discussed. It could be seen that with the excitation wavelength 350 nm, there was an obvious peak at 544 nm in the emission spectra of Dy3+/Tb3+ co-doped glass ceramics. With the increase of Tb4O7 concentration, energy transfer efficiency increased gradually, and when the Tb4O7 concentration was 1.9%(n/n), the luminescence intensity of green light reached maximum.Basing on the energy transfer theory of Dexter and the decay curves, the energy transfer from Dy3+ to Tb3+ was determined.
Dy3+/Tb3+ co-doped glass ceramics containing SrWO4 crystal were synthesized successfully by melt-crystallization method and luminescence properties were studied. The optimum heat treatment temperature and time were determined by differential scanning calorimetry (DSC), the precipitation of SrWO4 grains in the precursor glass was determined by X-ray diffraction (XRD) and combining with the transmittance curves, the optimum heat treatment system was determined at 710℃ for 1.5 h. When the concentration of Dy2O3 was 0.8%(n/n), the effect of Tb4O7 concentration on the luminescence properties of glass ceramic samples were discussed. It could be seen that with the excitation wavelength 350 nm, there was an obvious peak at 544 nm in the emission spectra of Dy3+/Tb3+ co-doped glass ceramics. With the increase of Tb4O7 concentration, energy transfer efficiency increased gradually, and when the Tb4O7 concentration was 1.9%(n/n), the luminescence intensity of green light reached maximum.Basing on the energy transfer theory of Dexter and the decay curves, the energy transfer from Dy3+ to Tb3+ was determined.
2019, 35(12): 2318-2322
doi: 10.11862/CJIC.2019.266
Abstract:
The flake Co9S8/ZnS/C composites were prepared by solvothermal method, through using cobalt hexahydrate[Co(NO3)2·6H2O] as cobalt source, zinc hexahydrate nitrate[Zn(NO3)2·6H2O] as zinc source and 2, 2'-thiodiacetic acid (C4H6O4S) as sulfur source. The flake Co9S8/ZnS/C composites structure and morphology were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), N2 adsorption-desorption test. Meanwhile, the results of electrocatalytic oxygen evolution reaction for the flake Co9S8/ZnS/C composite showed that it had high electrocatalytic oxygen production performance, with the initial overpotential of 390 mV and the Tafel slope of 144 mV·dec-1.
The flake Co9S8/ZnS/C composites were prepared by solvothermal method, through using cobalt hexahydrate[Co(NO3)2·6H2O] as cobalt source, zinc hexahydrate nitrate[Zn(NO3)2·6H2O] as zinc source and 2, 2'-thiodiacetic acid (C4H6O4S) as sulfur source. The flake Co9S8/ZnS/C composites structure and morphology were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), N2 adsorption-desorption test. Meanwhile, the results of electrocatalytic oxygen evolution reaction for the flake Co9S8/ZnS/C composite showed that it had high electrocatalytic oxygen production performance, with the initial overpotential of 390 mV and the Tafel slope of 144 mV·dec-1.
2019, 35(12): 2323-2330
doi: 10.11862/CJIC.2019.276
Abstract:
The synthesis of zeolite P by like-solid phase method was studied, using silicon aluminum xerogels as silicon source and aluminum source, and the sodium hydroxide as the alkali source. The products were characterized and analyzed by methods such as X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results showed that the zeolite P product with uniform morphology and good crystallinity can be prepared, when the nSiO2/nAl2O3 of the silicon aluminum xerogels was 5, the crystallization time and crystallization temperature were 3 h and 140℃, and the nNa2O/nSiO2 and nH2O/nSiO2 of the raw material were 0.26 and 18.51, respectively. Compared with the traditional hydrothermal method, the like-solid phase method greatly reduces the amount of water used in the synthesis process, shortens the crystallization time, improves the ion exchange performances of Ca2+ and Mg2+, and overall optimizes the synthesis process of zeolite P.
The synthesis of zeolite P by like-solid phase method was studied, using silicon aluminum xerogels as silicon source and aluminum source, and the sodium hydroxide as the alkali source. The products were characterized and analyzed by methods such as X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results showed that the zeolite P product with uniform morphology and good crystallinity can be prepared, when the nSiO2/nAl2O3 of the silicon aluminum xerogels was 5, the crystallization time and crystallization temperature were 3 h and 140℃, and the nNa2O/nSiO2 and nH2O/nSiO2 of the raw material were 0.26 and 18.51, respectively. Compared with the traditional hydrothermal method, the like-solid phase method greatly reduces the amount of water used in the synthesis process, shortens the crystallization time, improves the ion exchange performances of Ca2+ and Mg2+, and overall optimizes the synthesis process of zeolite P.
2019, 35(12): 2331-2336
doi: 10.11862/CJIC.2019.261
Abstract:
The low-cost cobalt nanoparticles were deposited on the channels of carbon nitride nanotubes (C3N4 NTs) by a chemical reduction process. The morphology and structures of the synthesized Co/C3N4 NTs nanocomposite were analyzed by comprehensive characterization methods. The effects of Co loading content on the visible-light-induced photocatalytic hydrogen production rate were studied. Our results show that this metal-semiconductor heterojunction effectively enhances the separation of photogenerated electron-holes. After 2 h of visible light irradiation, the optimal hydrogen production was obtained when the Co loading was 5%(w/w), and the hydrogen production rate was 1.7 times that of pure C3N4 NTs.
The low-cost cobalt nanoparticles were deposited on the channels of carbon nitride nanotubes (C3N4 NTs) by a chemical reduction process. The morphology and structures of the synthesized Co/C3N4 NTs nanocomposite were analyzed by comprehensive characterization methods. The effects of Co loading content on the visible-light-induced photocatalytic hydrogen production rate were studied. Our results show that this metal-semiconductor heterojunction effectively enhances the separation of photogenerated electron-holes. After 2 h of visible light irradiation, the optimal hydrogen production was obtained when the Co loading was 5%(w/w), and the hydrogen production rate was 1.7 times that of pure C3N4 NTs.
