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2017 Volume 80 Issue 8
2017, 80(8): 699-707
Abstract:
At present, chromatographic, spectroscopic, microscopic and electrochemical methods have been successfully used in the qualitative and quantitative study of separation and analysis of chiral compounds, and many significant progresses have been made over the past years. Among these approaches, electrochemical methods have attracted a lot of attention owing to the advantages of high sensitivity, simple instrument and fast detection. In this article, the research progress of electrochemical method for chiral recognition was reviewed, and the prospects of this field were also put forward.
At present, chromatographic, spectroscopic, microscopic and electrochemical methods have been successfully used in the qualitative and quantitative study of separation and analysis of chiral compounds, and many significant progresses have been made over the past years. Among these approaches, electrochemical methods have attracted a lot of attention owing to the advantages of high sensitivity, simple instrument and fast detection. In this article, the research progress of electrochemical method for chiral recognition was reviewed, and the prospects of this field were also put forward.
2017, 80(8): 708-714
Abstract:
The research progresses in the field of Fe3+-fluorescent probes based on coumarin during the past ten years are reviewed. Molecular design, mechanism and application of this kind of probes are briefly introduced. Moreover, the future trends of coumarin-based fluorescent probes for Fe3+ ion are briefly introduced.
The research progresses in the field of Fe3+-fluorescent probes based on coumarin during the past ten years are reviewed. Molecular design, mechanism and application of this kind of probes are briefly introduced. Moreover, the future trends of coumarin-based fluorescent probes for Fe3+ ion are briefly introduced.
2017, 80(8): 715-724
Abstract:
1α, 25-Dihydroxyvitamin D2(1α, 25-(OH)2-D2; 125D2) is the active metabolite form of vitamin D2, and 1α, 25-dihydroxyvitamin D3(1α, 25-(OH)2-D3; 125D) is the most active metabolite of vitamin D3. The biological activity of 125D2 and 125D is similar, but the therapeutic application of 125D is limited by induction of hypercalcemia. Vitamin D2 and analogues are thought to be generally less toxic than the respective vitamin D3 compounds. This article reviews the recent development of two 125D2 analogues (doxercalciferol and paricalcitol) showed good clinical effect in organic syntheses, and new research in the design and syntheses of the structural modifications in the side chain, 19-nor, C3-substituted in A ring, and nonadeuterated isotope labeling 125D2 analogues, and the relation between the structure and the biological activities, aimed at guiding significance to the syntheses and clinical development of new selective biological vitamin D2 analogues.
1α, 25-Dihydroxyvitamin D2(1α, 25-(OH)2-D2; 125D2) is the active metabolite form of vitamin D2, and 1α, 25-dihydroxyvitamin D3(1α, 25-(OH)2-D3; 125D) is the most active metabolite of vitamin D3. The biological activity of 125D2 and 125D is similar, but the therapeutic application of 125D is limited by induction of hypercalcemia. Vitamin D2 and analogues are thought to be generally less toxic than the respective vitamin D3 compounds. This article reviews the recent development of two 125D2 analogues (doxercalciferol and paricalcitol) showed good clinical effect in organic syntheses, and new research in the design and syntheses of the structural modifications in the side chain, 19-nor, C3-substituted in A ring, and nonadeuterated isotope labeling 125D2 analogues, and the relation between the structure and the biological activities, aimed at guiding significance to the syntheses and clinical development of new selective biological vitamin D2 analogues.
2017, 80(8): 725-733
Abstract:
Plakinidines and analogues are the pyrrolacridine and pyridoacridine polycyclic alkaloids that are isolated from ocean mollusks. And plakinidines are the first class of pyrrolacridine containing alkaloids found in marine extracts, some of which have good biological activities such as anti-cancer and anti-parasite. In this paper, studies on the extraction, isolation, structural elucidation, bio-activity and chemical synthesis of plakinidines and analogous alkaloids are reviewed.
Plakinidines and analogues are the pyrrolacridine and pyridoacridine polycyclic alkaloids that are isolated from ocean mollusks. And plakinidines are the first class of pyrrolacridine containing alkaloids found in marine extracts, some of which have good biological activities such as anti-cancer and anti-parasite. In this paper, studies on the extraction, isolation, structural elucidation, bio-activity and chemical synthesis of plakinidines and analogous alkaloids are reviewed.
2017, 80(8): 734-739
Abstract:
Cobalt sulfide (CoS) counter electrode(CE) in dye-sensitized solar cells(DSSC) was successfully prepared by a simple solid-gas reaction method on the conductive glass of fluorine doped tin oxide. The optimal concentration of CoS was further confirmed by optimizing the process. The surface morphology, material structure, electrocatalytic and photovoltaic performances were characterized by SEM, XRD, Raman spectroscopy, XPS, EIS, CV, Tafel polarization curves and photoelectric current density voltage characteristic curves. The results showed that CoS prepared from 20% cobalt acetate had higher electrocatalytic activity as a counter electrode. Under standard illumination of one sun (100 mW·cm-2), the DSSC incorporating CoS-decorated FTO glass substrate as a CE provide PCE of 7.81% with Jsc of 17.3 mA·cm-2, Voc of 0.74V, and FF of 0.61, which are comparable with the values obtained for the device with a Pt-based CE (PCE: 7.97%).
Cobalt sulfide (CoS) counter electrode(CE) in dye-sensitized solar cells(DSSC) was successfully prepared by a simple solid-gas reaction method on the conductive glass of fluorine doped tin oxide. The optimal concentration of CoS was further confirmed by optimizing the process. The surface morphology, material structure, electrocatalytic and photovoltaic performances were characterized by SEM, XRD, Raman spectroscopy, XPS, EIS, CV, Tafel polarization curves and photoelectric current density voltage characteristic curves. The results showed that CoS prepared from 20% cobalt acetate had higher electrocatalytic activity as a counter electrode. Under standard illumination of one sun (100 mW·cm-2), the DSSC incorporating CoS-decorated FTO glass substrate as a CE provide PCE of 7.81% with Jsc of 17.3 mA·cm-2, Voc of 0.74V, and FF of 0.61, which are comparable with the values obtained for the device with a Pt-based CE (PCE: 7.97%).
2017, 80(8): 740-744, 714
Abstract:
Au/SrTiO3 plasmonic nanophotocatalysts were prepared by hydrothermal and photo-deposition methods. The structure, composition, morphology, size and optical property of the as-prepared photocatalysts were characterized by XRD, XPS, SEM, TEM, EDS-mapping and UV-Visible diffuse reflectance spectroscopy. The photocatalytic hydrogen-production performance of Au/SrTiO3 plasmonic photocatalysts was tested under visible light. The results showed that SrTiO3 nanoparticles were successfully prepared by hydrothermal method. Due to the surface plasmon resonance effect of Au, the SrTiO3 nanoparticles exhibited improved light absorption in the visible-light region. Moreover, the effect of different Au loading amounts on the photocatalytic hydrogen-production activity of SrTiO3 plasmonic nanophotocatalysts was investigated. Among them, the 5%Au/SrTiO3 photocatalyst showed the highest hydrogen production activity. In addition, the photocatalytic mechanism was also discussed.
Au/SrTiO3 plasmonic nanophotocatalysts were prepared by hydrothermal and photo-deposition methods. The structure, composition, morphology, size and optical property of the as-prepared photocatalysts were characterized by XRD, XPS, SEM, TEM, EDS-mapping and UV-Visible diffuse reflectance spectroscopy. The photocatalytic hydrogen-production performance of Au/SrTiO3 plasmonic photocatalysts was tested under visible light. The results showed that SrTiO3 nanoparticles were successfully prepared by hydrothermal method. Due to the surface plasmon resonance effect of Au, the SrTiO3 nanoparticles exhibited improved light absorption in the visible-light region. Moreover, the effect of different Au loading amounts on the photocatalytic hydrogen-production activity of SrTiO3 plasmonic nanophotocatalysts was investigated. Among them, the 5%Au/SrTiO3 photocatalyst showed the highest hydrogen production activity. In addition, the photocatalytic mechanism was also discussed.
2017, 80(8): 745-750, 759
Abstract:
Graphene materials with ample mesopores were prepared by a magnesiothermic reaction using CO2 as carbon source. XRD, SEM, TEM, Raman spectroscopy and N2 desorption/adsorption were used to characterize the microstructure of graphene materials. It was found that the morphologies and pore structure of graphene were controllable simply by changing the mass ratio of Mg and MgO in the starting materials. The product (MRG-8) obtained with MgO/Mg mass ratio of 8:1 showed a uniform mesopore size of 4 nm. The electrochemical properties of products were also evaluated. In 1 mol/L KOH electrolyte, MRG-8 displayed a high specific capacitance of 171 F/g and an excellent rate performance. The capacitance retention rate of MRG-8 is up to 94% after 12000 cycles. Using ionic liquid [EMIM][BF4] as electrolyte, symmetric supercapacitors of MRG-8 exhibited an ultra-high power density of 175kW/kg and a corresponding energy density of 28.1kW/kg. This work is expected to offer a novel method for mesoporous graphene production, which may be promising in the application of high-power supercapacitors.
Graphene materials with ample mesopores were prepared by a magnesiothermic reaction using CO2 as carbon source. XRD, SEM, TEM, Raman spectroscopy and N2 desorption/adsorption were used to characterize the microstructure of graphene materials. It was found that the morphologies and pore structure of graphene were controllable simply by changing the mass ratio of Mg and MgO in the starting materials. The product (MRG-8) obtained with MgO/Mg mass ratio of 8:1 showed a uniform mesopore size of 4 nm. The electrochemical properties of products were also evaluated. In 1 mol/L KOH electrolyte, MRG-8 displayed a high specific capacitance of 171 F/g and an excellent rate performance. The capacitance retention rate of MRG-8 is up to 94% after 12000 cycles. Using ionic liquid [EMIM][BF4] as electrolyte, symmetric supercapacitors of MRG-8 exhibited an ultra-high power density of 175kW/kg and a corresponding energy density of 28.1kW/kg. This work is expected to offer a novel method for mesoporous graphene production, which may be promising in the application of high-power supercapacitors.
2017, 80(8): 760-764
Abstract:
Mn(Ⅱ) coordination compound, Mn(o-PAMH)(H2O)2 (o-PAMH=2-oxo-propionic acid 2-methoxy benzoyl hydrazone), has been synthesized using solution diffusion method at room temperature. The crystal structure and characteristics of the coordination compound were determined by X-ray crystallography and thermogravimetric analysis (TGA). Single-crystal X-ray diffraction analysis revealed that the complex was crystallized in the monoclinic space group P-1 with unit cell parameters a=0.7925(2) nm, b=1.0529(3) nm, c=1.1069(4) nm, α=68.142(6)°, β=69.053(4)°, γ=71.292(4)°, V=0.7816(4) nm3, and Z=1. The asymmetric unit contains only one crystallographically independent manganese ion, which is seven-coordinated and exhibits slightly distorted pentagonal bipyramid geometry. The complex displays a dinuclear and zero dimensional structure. The ultraviolet and fluorescent properties of the complex have been investigated.
Mn(Ⅱ) coordination compound, Mn(o-PAMH)(H2O)2 (o-PAMH=2-oxo-propionic acid 2-methoxy benzoyl hydrazone), has been synthesized using solution diffusion method at room temperature. The crystal structure and characteristics of the coordination compound were determined by X-ray crystallography and thermogravimetric analysis (TGA). Single-crystal X-ray diffraction analysis revealed that the complex was crystallized in the monoclinic space group P-1 with unit cell parameters a=0.7925(2) nm, b=1.0529(3) nm, c=1.1069(4) nm, α=68.142(6)°, β=69.053(4)°, γ=71.292(4)°, V=0.7816(4) nm3, and Z=1. The asymmetric unit contains only one crystallographically independent manganese ion, which is seven-coordinated and exhibits slightly distorted pentagonal bipyramid geometry. The complex displays a dinuclear and zero dimensional structure. The ultraviolet and fluorescent properties of the complex have been investigated.
2017, 80(8): 765-771
Abstract:
Three different Schiff bases containing adamantanyl ester of formyl benzoic acid and their Ni(Ⅱ) complexes were synthesized using adamantanol, 4-formylbenzoic acid, o-aminophenal, 2-aminothiophenol and 2-bromoaniline as raw materials. Their structures were characterized by IR, UV-Vis and NMR spectroscopies. The fluorescence properties, thermal stabilities and electrochemical properties of Schiff bases and their Ni(Ⅱ) complexes were studied through fluorescence spectra, thermogravimetric analysis and electrochemical techniques. The results indicated that Ni(Ⅱ) complexes H1, H2 and H3 have good fluorescence properties and H1, H2 exhibit high electrochemical activity.
Three different Schiff bases containing adamantanyl ester of formyl benzoic acid and their Ni(Ⅱ) complexes were synthesized using adamantanol, 4-formylbenzoic acid, o-aminophenal, 2-aminothiophenol and 2-bromoaniline as raw materials. Their structures were characterized by IR, UV-Vis and NMR spectroscopies. The fluorescence properties, thermal stabilities and electrochemical properties of Schiff bases and their Ni(Ⅱ) complexes were studied through fluorescence spectra, thermogravimetric analysis and electrochemical techniques. The results indicated that Ni(Ⅱ) complexes H1, H2 and H3 have good fluorescence properties and H1, H2 exhibit high electrochemical activity.
2017, 80(8): 772-776
Abstract:
1, 2, 4, 5-tetraphenyl-3, 6-di(3, 5-dibromophenyl)benzene (6a) was synthesized by Diels-Alder cycloaddition reaction of 2, 5-bis(3, 5-dibromophenyl)-3, 4-diphenylcyclopenta-2, 4-dienone (4a) with 1, 2-diphenylethyne (5a). 1, 2, 4, 5-tetraphenyl-3, 6-di(3, 5-di(4-dodecylthiophene))phenylbenzene (8a) was obtained from 6a by classical Suzuki coupling reaction, then the target compound 1a was obtained for 8a by Scholl cyclodehydrogenation using FeCl3 as catalyst. The similar synthesis method was used to obtain the target compound 1b. The structures of these compounds were characterized by 1H NMR and MALDI-TOF MS, and their spectral characteristics, thermal and electrical properties were investigated.
1, 2, 4, 5-tetraphenyl-3, 6-di(3, 5-dibromophenyl)benzene (6a) was synthesized by Diels-Alder cycloaddition reaction of 2, 5-bis(3, 5-dibromophenyl)-3, 4-diphenylcyclopenta-2, 4-dienone (4a) with 1, 2-diphenylethyne (5a). 1, 2, 4, 5-tetraphenyl-3, 6-di(3, 5-di(4-dodecylthiophene))phenylbenzene (8a) was obtained from 6a by classical Suzuki coupling reaction, then the target compound 1a was obtained for 8a by Scholl cyclodehydrogenation using FeCl3 as catalyst. The similar synthesis method was used to obtain the target compound 1b. The structures of these compounds were characterized by 1H NMR and MALDI-TOF MS, and their spectral characteristics, thermal and electrical properties were investigated.
2017, 80(8): 777-782, 771
Abstract:
The presence of ionic liquids (ILs) has a significant impact on the aggregation behavior of surfactants in aqueous solution. In this article, micellization of non-ionic surfactant Tween-20 with the presence of middle and low concentration of hydrophilic ionic liquid [bmim][BF4] (1-butyl-3-methylimidazolium tetrafluoroborate) was investigated. Critical micellization concentration (CMC) of Tween-20 showed an upward trend while increasing concentration of [bmim][BF4] from 0 to 0.2 mol·L-1. Aggregation number of Tween-20 micelles decreased with increasing the concentration of [bmim][BF4], which also indicated that the presence of [bmim][BF4] had great effect on hindering the micellization of Tween-20. Thermodynamic investigation demonstrated that the micellization of Tween-20 was driven by both entropy and enthalpy, and also showed entropy-enthalpy compensation. Meanwhile, average particle size and micro-viscosity of Tween-20 micelles increased first and then decreased with increasing concentration of [bmim][BF4] from 0 to 0.2 mol·L-1, reaching the peak values at cIL=0.05 mol·L-1.
The presence of ionic liquids (ILs) has a significant impact on the aggregation behavior of surfactants in aqueous solution. In this article, micellization of non-ionic surfactant Tween-20 with the presence of middle and low concentration of hydrophilic ionic liquid [bmim][BF4] (1-butyl-3-methylimidazolium tetrafluoroborate) was investigated. Critical micellization concentration (CMC) of Tween-20 showed an upward trend while increasing concentration of [bmim][BF4] from 0 to 0.2 mol·L-1. Aggregation number of Tween-20 micelles decreased with increasing the concentration of [bmim][BF4], which also indicated that the presence of [bmim][BF4] had great effect on hindering the micellization of Tween-20. Thermodynamic investigation demonstrated that the micellization of Tween-20 was driven by both entropy and enthalpy, and also showed entropy-enthalpy compensation. Meanwhile, average particle size and micro-viscosity of Tween-20 micelles increased first and then decreased with increasing concentration of [bmim][BF4] from 0 to 0.2 mol·L-1, reaching the peak values at cIL=0.05 mol·L-1.
2017, 80(8): 783-788
Abstract:
In pH 3.5 HAc-NaAc buffer medium, metformin hydrochloride(MFH) reacted with palladium(Ⅱ) (Pd(Ⅱ)) to form chelate cation, which further reacted with eosin Y (EY) to form the ternary ion-association complexes [Pd·MFH] (EY)2, and the spectra of the system were recorded with synchronous scanning at λem=λex (Δλ=0nm). The intensities of resonance Rayleigh scattering (RRS), second-order scattering (SOS) and frequency doubling scattering (FDS) were enhanced greatly and new scattering spectra appeared. The maximum RRS, SOS and FDS wavelengths of three ion-association complexes were located at 292nm, 540nm and 327nm, respectively. The increments of scattering intensity (ΔIRRS, ΔISOS and ΔIFDS) were directly proportional to the concentration of MFH in certain ranges. The detection limits (3σ) of Pd(Ⅱ)-MFH-EY system were 1.7ng·mL-1 (RRS method), 13.2ng·mL-1 (SOS method) and 22.7ng·mL-1 (FDS method), separately. The optimum conditions of RRS method and the influence factors were discussed, in addition, the structure of ion-association complex and the reaction mechanism were investigated. Based on the ion-association reaction and its spectral response, the rapid, simple and sensitive RRS method for the determination of MFH had been developed. It had been applied to the determination of MFH in tablets and urine samples with satisfactory results.
In pH 3.5 HAc-NaAc buffer medium, metformin hydrochloride(MFH) reacted with palladium(Ⅱ) (Pd(Ⅱ)) to form chelate cation, which further reacted with eosin Y (EY) to form the ternary ion-association complexes [Pd·MFH] (EY)2, and the spectra of the system were recorded with synchronous scanning at λem=λex (Δλ=0nm). The intensities of resonance Rayleigh scattering (RRS), second-order scattering (SOS) and frequency doubling scattering (FDS) were enhanced greatly and new scattering spectra appeared. The maximum RRS, SOS and FDS wavelengths of three ion-association complexes were located at 292nm, 540nm and 327nm, respectively. The increments of scattering intensity (ΔIRRS, ΔISOS and ΔIFDS) were directly proportional to the concentration of MFH in certain ranges. The detection limits (3σ) of Pd(Ⅱ)-MFH-EY system were 1.7ng·mL-1 (RRS method), 13.2ng·mL-1 (SOS method) and 22.7ng·mL-1 (FDS method), separately. The optimum conditions of RRS method and the influence factors were discussed, in addition, the structure of ion-association complex and the reaction mechanism were investigated. Based on the ion-association reaction and its spectral response, the rapid, simple and sensitive RRS method for the determination of MFH had been developed. It had been applied to the determination of MFH in tablets and urine samples with satisfactory results.
2017, 80(8): 751-759
Abstract:
Two kinds of activated carbons (ACs) were activated by steam, and a series of Bi/AC catalysts supported on steam-activated ACs were prepared by incipient-wetness impregnation method. Their catalytic performance for acetylene hydrochlorination was investigated. The characterizations of ACs and catalysts were conducted by N2 adsorption-desorption experiments (BET), scanning electron microscopy (SEM), Fourier transform-infrared spectroscopy (FTIR), transmission electron microscopy (TEM), powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and thermogravimetric analysis (TGA) methods, respectively. The results revealed that: (1) Steam activation reorganized the pore size and channel structure of ACs, especially for the mesoporous AC, whose specific surface area was increased and new micropore structure was formed; (2) Steam activation decreased the amount of coke deposition, which was the decisive factors affecting the catalytic activity, and generated a higher degree of crystallinity and a better dispersity of BiOCl, thus improving the catalytic performance for acetylene hydrochlorination.
Two kinds of activated carbons (ACs) were activated by steam, and a series of Bi/AC catalysts supported on steam-activated ACs were prepared by incipient-wetness impregnation method. Their catalytic performance for acetylene hydrochlorination was investigated. The characterizations of ACs and catalysts were conducted by N2 adsorption-desorption experiments (BET), scanning electron microscopy (SEM), Fourier transform-infrared spectroscopy (FTIR), transmission electron microscopy (TEM), powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and thermogravimetric analysis (TGA) methods, respectively. The results revealed that: (1) Steam activation reorganized the pore size and channel structure of ACs, especially for the mesoporous AC, whose specific surface area was increased and new micropore structure was formed; (2) Steam activation decreased the amount of coke deposition, which was the decisive factors affecting the catalytic activity, and generated a higher degree of crystallinity and a better dispersity of BiOCl, thus improving the catalytic performance for acetylene hydrochlorination.
2017, 80(8): 789-791
Abstract:
Benzothiazol-2-yl-methanol was synthesized by the reaction of 2-aminothiophenol with glycolic acid, and then was oxidized to give benzothiazole-2-formaldehyde. By comparing the effects of several oxidants, manganese dioxide was selected as the appropriate agent for the oxidation reaction, and the influence of feed ratio of the raw materials and reaction time on the yield of the product were also studied. The optimum oxidation reaction conditions were as follows: molar ratio of benzothiazol-2-yl-methanol to manganese dioxide is 1:8, reaction time is 8 h. The yield can reach 90.2%. This synthetic route is suitable for the industrial production of titled compound and its derivatives.
Benzothiazol-2-yl-methanol was synthesized by the reaction of 2-aminothiophenol with glycolic acid, and then was oxidized to give benzothiazole-2-formaldehyde. By comparing the effects of several oxidants, manganese dioxide was selected as the appropriate agent for the oxidation reaction, and the influence of feed ratio of the raw materials and reaction time on the yield of the product were also studied. The optimum oxidation reaction conditions were as follows: molar ratio of benzothiazol-2-yl-methanol to manganese dioxide is 1:8, reaction time is 8 h. The yield can reach 90.2%. This synthetic route is suitable for the industrial production of titled compound and its derivatives.
