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2016 Volume 79 Issue 9
2016, 79(9): 787-792
Abstract:
Tetrathiafulvalene (TTF) and its derivatives have received tremendous attentions owing to their applications in organic electronics. The research of TTFs includes the design and synthesis of functional molecules, supramolecular assembly, and elucidation of the physical properties of the supramolecular materials. Herein, we report the recent progress on arylthio-substituted/fused TTFs (Ar-S-TTF), on which the aryls are decorated onto the TTF core through the connection of sulfur bridges. We mainly highlight the facile synthesis, optical/electrochemical property, and structural feature of Ar-S-TTF, as well as the supramolecular assembly of Ar-S-TTF with fullerene and Keggin-type phosphomolybdic acid.
Tetrathiafulvalene (TTF) and its derivatives have received tremendous attentions owing to their applications in organic electronics. The research of TTFs includes the design and synthesis of functional molecules, supramolecular assembly, and elucidation of the physical properties of the supramolecular materials. Herein, we report the recent progress on arylthio-substituted/fused TTFs (Ar-S-TTF), on which the aryls are decorated onto the TTF core through the connection of sulfur bridges. We mainly highlight the facile synthesis, optical/electrochemical property, and structural feature of Ar-S-TTF, as well as the supramolecular assembly of Ar-S-TTF with fullerene and Keggin-type phosphomolybdic acid.
2016, 79(9): 793-797,792
Abstract:
Surface tension is an important thermophysical property of fluids. Methods for measuring surface tension often include capillary rise method, maximum bubble pressure method, Wilhelmy plate/Du Noüy ring method, drop weight/drop volume method, spinning drop method and pendent drop method. This article mainly introduces renewal surface tension and surface pressure measure methods, especially the improved testing technology of surface tension based on the method of maximum pull (Wilhelmy plate) in details. And the applications of this technology in the field of biological research, pharmaceutical R&D, environmental monitoring and so on in recent years are summarized.
Surface tension is an important thermophysical property of fluids. Methods for measuring surface tension often include capillary rise method, maximum bubble pressure method, Wilhelmy plate/Du Noüy ring method, drop weight/drop volume method, spinning drop method and pendent drop method. This article mainly introduces renewal surface tension and surface pressure measure methods, especially the improved testing technology of surface tension based on the method of maximum pull (Wilhelmy plate) in details. And the applications of this technology in the field of biological research, pharmaceutical R&D, environmental monitoring and so on in recent years are summarized.
2016, 79(9): 798-804
Abstract:
Nitrite is a toxic and carcinogenic substance, and it is characteristic pollutant which widely exists in the natural environment and human life. As a consequence of the recognized problems, it is urgent and significant to carry out the rapid and sensitive determination for nitrite. Electrochemical approaches have gained more and more attention owing to rapid reaction rate, higher sensitivity and lower detection limit, etc. In this review, based on the electrochemical sensing materials with different matrices and active materials, we outlined a series of electrochemical sensors for nitrite in detail. We put special emphasis on the synthetic approaches and the performances of sensing devices. The comparisons with the individuality and commonness would further promote the development of practical electrochemical sensors for nitrite.
Nitrite is a toxic and carcinogenic substance, and it is characteristic pollutant which widely exists in the natural environment and human life. As a consequence of the recognized problems, it is urgent and significant to carry out the rapid and sensitive determination for nitrite. Electrochemical approaches have gained more and more attention owing to rapid reaction rate, higher sensitivity and lower detection limit, etc. In this review, based on the electrochemical sensing materials with different matrices and active materials, we outlined a series of electrochemical sensors for nitrite in detail. We put special emphasis on the synthetic approaches and the performances of sensing devices. The comparisons with the individuality and commonness would further promote the development of practical electrochemical sensors for nitrite.
2016, 79(9): 805-810,816
Abstract:
Vanadium oxide micro/nano hollow spheres are widely studied and utilized in the industries of catalyst, sensor, lithium-ion battery and battery cathode material due to its high specific surface area, large load capacity and low density. The preparation methods of vanadium oxide micro/nano hollow spheres materials, such as soft template, hard template, hydrothermal synthesis and solvothermal synthesis, and relevant research progress are reviewed in this paper. Finally the future research direction is discussed.
Vanadium oxide micro/nano hollow spheres are widely studied and utilized in the industries of catalyst, sensor, lithium-ion battery and battery cathode material due to its high specific surface area, large load capacity and low density. The preparation methods of vanadium oxide micro/nano hollow spheres materials, such as soft template, hard template, hydrothermal synthesis and solvothermal synthesis, and relevant research progress are reviewed in this paper. Finally the future research direction is discussed.
2016, 79(9): 811-816
Abstract:
Rebaudioside A (RA) is the main component of steviol glycosides (SGs) which is extracted from stevia leaves. As a nonrestrictive used natural sweetener, RA has been used widely in the fields of beverages, foods and pharmaceutical industry, because of high sweetness, low calorie and no poisonous effect. RA is described as ‘the third sweetener resources’ in the world after sucrose and glucose. Therefore, the extraction and refining technology of RA is brought into research hotspot. There are three types of methods to separate RA from SGs through utilizing (1) RA solubility difference with other components of SGs, (2) RA polarity difference with other components of SGs and (3) adsorption properties of RA in macroporous adsorption resins (MARs). In addition, Membrane separation technique (MST) is used to refine RA in recent years. Among them, recrystallization and resin method are used to produce RA in industry, and chromatography is often used in laboratory to refine RA.
Rebaudioside A (RA) is the main component of steviol glycosides (SGs) which is extracted from stevia leaves. As a nonrestrictive used natural sweetener, RA has been used widely in the fields of beverages, foods and pharmaceutical industry, because of high sweetness, low calorie and no poisonous effect. RA is described as ‘the third sweetener resources’ in the world after sucrose and glucose. Therefore, the extraction and refining technology of RA is brought into research hotspot. There are three types of methods to separate RA from SGs through utilizing (1) RA solubility difference with other components of SGs, (2) RA polarity difference with other components of SGs and (3) adsorption properties of RA in macroporous adsorption resins (MARs). In addition, Membrane separation technique (MST) is used to refine RA in recent years. Among them, recrystallization and resin method are used to produce RA in industry, and chromatography is often used in laboratory to refine RA.
2016, 79(9): 817-821
Abstract:
A platinum polyyne PtDPP with 2,5-bis(2-octyl-dodecyl)-3,6-di(thiophen-2-yl)pyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione as co-unit was synthesized and characterized. The LUMO and HOMO energy of PtDPP was estimated to be -3.4 eV and -5.3 eV by cyclic voltammogram and UV-Vis spectrum. Bottom gate bottom contact OFET devices of PtDPP were fabricated via spin coating. After annealing at 160℃, the OFET devices show highest performance with hole mobility up to 1.0×10-3cm2·V-1·s-1, on/off ratio of 105 and threshold voltage of -15 V. Further investigation on XRD and AFM suggested that the crytalline order enhanced along the annealing process.
A platinum polyyne PtDPP with 2,5-bis(2-octyl-dodecyl)-3,6-di(thiophen-2-yl)pyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione as co-unit was synthesized and characterized. The LUMO and HOMO energy of PtDPP was estimated to be -3.4 eV and -5.3 eV by cyclic voltammogram and UV-Vis spectrum. Bottom gate bottom contact OFET devices of PtDPP were fabricated via spin coating. After annealing at 160℃, the OFET devices show highest performance with hole mobility up to 1.0×10-3cm2·V-1·s-1, on/off ratio of 105 and threshold voltage of -15 V. Further investigation on XRD and AFM suggested that the crytalline order enhanced along the annealing process.
2016, 79(9): 822-827
Abstract:
Ni/AC nano catalysts with different Ni loading on activated carbon(AC) were prepared by incipient wetness impregnation and temperature programmed reduction method. Their morphology and structure were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM) and X-ray photoelectron spectroscopy (XPS). Cyclic voltammetry was used to explore their activity for elctrocatalytic oxidation of glucose. The results showed that 20%Ni/AC/GC (Ni/AC nano catalyst was modified on a glassy carbon electrode) electrodes had a superior electrocatalytic activity for glucose oxidation. It brought a distinct and fast voltaic response in alkaline medium and the response current was significantly increased with the increase of glucose concentration. The linear response range of 20%Ni/AC/GCE was 0.2~6.5 mmol/L, the correlation coefficient was 0.999, the sensitivity was 13.15 μA/(mmol/L) and the lowest detectable limit was 35 μmol/L. It was found that the response current of 20%Ni/AC/GCE for glucose electrocatalytic oxidation could be able to reach 95% of the original current after three weeks when it was tested every three days, which indicates the Ni/AC/GCE electrode has a good stability.
Ni/AC nano catalysts with different Ni loading on activated carbon(AC) were prepared by incipient wetness impregnation and temperature programmed reduction method. Their morphology and structure were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM) and X-ray photoelectron spectroscopy (XPS). Cyclic voltammetry was used to explore their activity for elctrocatalytic oxidation of glucose. The results showed that 20%Ni/AC/GC (Ni/AC nano catalyst was modified on a glassy carbon electrode) electrodes had a superior electrocatalytic activity for glucose oxidation. It brought a distinct and fast voltaic response in alkaline medium and the response current was significantly increased with the increase of glucose concentration. The linear response range of 20%Ni/AC/GCE was 0.2~6.5 mmol/L, the correlation coefficient was 0.999, the sensitivity was 13.15 μA/(mmol/L) and the lowest detectable limit was 35 μmol/L. It was found that the response current of 20%Ni/AC/GCE for glucose electrocatalytic oxidation could be able to reach 95% of the original current after three weeks when it was tested every three days, which indicates the Ni/AC/GCE electrode has a good stability.
2016, 79(9): 828-833,804
Abstract:
The Mn2+ doped-polyaniline(PANI)/reduced graphene oxide (rGO) composite was successfully prepared via a simple in-situ chemical oxidative polymerization method.FT IR, XRD, SEM and electrochemical measurements were employed to investigate the structure, morphology and electrochemical capacitance performance of the composite. The results showed that the Mn2+ doped-polyaniline with nanorods structure was well distributed into the corrugated graphene layers, and the porous cross-linked structure was formed. The specific capacitance of as-prepared PANI/rGO compsite is 952 F/g under the current density of 2 A/g. After 1000 cycles, the capacitance value remains about 86.2% of that of initial cycle. Transition metal doping and rGO enhanced the electrochemical properties of the nanocomposites. The better specific capacitance and charge/discharge rates make them promising candidates as electrodes in supercapacitors.
The Mn2+ doped-polyaniline(PANI)/reduced graphene oxide (rGO) composite was successfully prepared via a simple in-situ chemical oxidative polymerization method.FT IR, XRD, SEM and electrochemical measurements were employed to investigate the structure, morphology and electrochemical capacitance performance of the composite. The results showed that the Mn2+ doped-polyaniline with nanorods structure was well distributed into the corrugated graphene layers, and the porous cross-linked structure was formed. The specific capacitance of as-prepared PANI/rGO compsite is 952 F/g under the current density of 2 A/g. After 1000 cycles, the capacitance value remains about 86.2% of that of initial cycle. Transition metal doping and rGO enhanced the electrochemical properties of the nanocomposites. The better specific capacitance and charge/discharge rates make them promising candidates as electrodes in supercapacitors.
2016, 79(9): 834-838
Abstract:
An ultrasound-assisted Biginelli reaction catalysized by I2 loaded montmorillonite was developed using ethylacetoacetate, aromatic aldehyde and urea as starting materials. Influences of solvents, catalysts on the yield were investigated using single factor methods, and the temperature, ultrasonic time, equivalent ratio of starting materials were screened using orthogonal tests. Under the optimized conditoin, the yields of 3,4-dihydropyrimidin-2(1H)one derivatives were up to 86.9%. The products were characterized by 1H NMR, IR and m.p.
An ultrasound-assisted Biginelli reaction catalysized by I2 loaded montmorillonite was developed using ethylacetoacetate, aromatic aldehyde and urea as starting materials. Influences of solvents, catalysts on the yield were investigated using single factor methods, and the temperature, ultrasonic time, equivalent ratio of starting materials were screened using orthogonal tests. Under the optimized conditoin, the yields of 3,4-dihydropyrimidin-2(1H)one derivatives were up to 86.9%. The products were characterized by 1H NMR, IR and m.p.
2016, 79(9): 839-843
Abstract:
An Er(III) complex of Er(ina)3(phen)·H2O[ina=isonicotinic acid, phen=1,10-phenanthrolin] has been synthesized and characterized. X-ray single crystal diffraction reveals that, in the complex, the central Er(III) ion adopts an eight-coordinated distorted square anti-prism coordination geometry with O6N2 set, where one oxygen atom is from a water molecule and five oxygen atoms come from three ina ligands while two nitrogen atoms are from the phen ligand. In the crystal, two O-H…N hydrogen bonds along with a C-H…π and π…π supramoleuclar interactions fabricate 2D networks which further generate a 3D supramolecular architecture via interlayer π…π interactions and extensive C-H…O hydrogen bonds. Fluorescent spectra below 1000 nm show that the titled complex emits purple fluorescence.
An Er(III) complex of Er(ina)3(phen)·H2O[ina=isonicotinic acid, phen=1,10-phenanthrolin] has been synthesized and characterized. X-ray single crystal diffraction reveals that, in the complex, the central Er(III) ion adopts an eight-coordinated distorted square anti-prism coordination geometry with O6N2 set, where one oxygen atom is from a water molecule and five oxygen atoms come from three ina ligands while two nitrogen atoms are from the phen ligand. In the crystal, two O-H…N hydrogen bonds along with a C-H…π and π…π supramoleuclar interactions fabricate 2D networks which further generate a 3D supramolecular architecture via interlayer π…π interactions and extensive C-H…O hydrogen bonds. Fluorescent spectra below 1000 nm show that the titled complex emits purple fluorescence.
2016, 79(9): 844-851
Abstract:
CCR2 plays an important role in aspects of inflammation, transplantation immune rejection and tumor formation. It has become a new biological treatment target. Based on using crystal structure of CCR5 as template, homologous model of CCR2 was built, then docking with small molecule inhibitors to get the optimum configuration of small molecule. The best evaluation parameters of comparative molecular field analysis (CoMFA) and comparative molecular similarity analysis (CoMSIA) models are q2=0.743, r2=0.968 and q2=0.68, r2=0.978, respectively. Through analyzing the potential diagram of 3D-QSAR models, we may safely draw the conclusion that modification on R3 groups can improve the activity of the compound. The established model has a strong ability of prediction. This paper may provide a reference for design, optimization and transformation of small molecule inhibitors CCR2.
CCR2 plays an important role in aspects of inflammation, transplantation immune rejection and tumor formation. It has become a new biological treatment target. Based on using crystal structure of CCR5 as template, homologous model of CCR2 was built, then docking with small molecule inhibitors to get the optimum configuration of small molecule. The best evaluation parameters of comparative molecular field analysis (CoMFA) and comparative molecular similarity analysis (CoMSIA) models are q2=0.743, r2=0.968 and q2=0.68, r2=0.978, respectively. Through analyzing the potential diagram of 3D-QSAR models, we may safely draw the conclusion that modification on R3 groups can improve the activity of the compound. The established model has a strong ability of prediction. This paper may provide a reference for design, optimization and transformation of small molecule inhibitors CCR2.
2016, 79(9): 852-855,851
Abstract:
The introduction of twistacene unit into polymers can decrease the fluorescence quenching in the solid state, which provides more room to approach the electroluminescent materials. Four novel linear twistacene-functionalized polymers P1~P4 are synthesized through classical Suzuki coupling reaction. In THF solution or as thin film, all of them show similar absorption profiles and have two broad absorption peaks between 302 nm and 417 nm. In comparison, the emission bands were red-shift in thin film and emit strong blue light. TGA analysis suggested that P1~P4 were stable up to 350℃. In addition, their electrochemical behaviors were further tested using CV method.
The introduction of twistacene unit into polymers can decrease the fluorescence quenching in the solid state, which provides more room to approach the electroluminescent materials. Four novel linear twistacene-functionalized polymers P1~P4 are synthesized through classical Suzuki coupling reaction. In THF solution or as thin film, all of them show similar absorption profiles and have two broad absorption peaks between 302 nm and 417 nm. In comparison, the emission bands were red-shift in thin film and emit strong blue light. TGA analysis suggested that P1~P4 were stable up to 350℃. In addition, their electrochemical behaviors were further tested using CV method.
2016, 79(9): 856-859,875
Abstract:
The fluorescence probe for specifically bio-molecule site labeling could be used to investigate structures and functions of proteins. The rigidity and high labeling selectivity of the fluorescence probe is critical to the study on protein dynamics using FRET. Here, we describe two synthesis methods of two cyanine probes, IAM-Cyanine3 and IAM-Cyanine5. The two probes are attached onto the protein surface through reaction between the iodacetamide group of the probe and the thiol group on the protein surface. Compared to common commercial probes, our probes possess lower flexibility after being attached onto proteins, leading to better resolution of bio-macromolecule dynamics and structures.
The fluorescence probe for specifically bio-molecule site labeling could be used to investigate structures and functions of proteins. The rigidity and high labeling selectivity of the fluorescence probe is critical to the study on protein dynamics using FRET. Here, we describe two synthesis methods of two cyanine probes, IAM-Cyanine3 and IAM-Cyanine5. The two probes are attached onto the protein surface through reaction between the iodacetamide group of the probe and the thiol group on the protein surface. Compared to common commercial probes, our probes possess lower flexibility after being attached onto proteins, leading to better resolution of bio-macromolecule dynamics and structures.
2016, 79(9): 860-863
Abstract:
Four kinds of different ionic liquids were investigated as novel co-solvents for synthesis of p-toluene sulfonyl chloride (TsCl) with p-toluene sulfonyl acid (TsOH) and chlorosulfonic acid (ClSO3H) as feedstocks in ethylidene chloride. The effect of ionic liquids on solubility ratio (s value) of TsOH in ethylidene chloride and sulphuric acid, as well as the yield of TsCl was studied particularly. The results showed that the s value of TsOH was significantly enhanced with increasing of ionic liquid amount. The yield of TsCl thus was also increased, correspondingly. Among four screened ionic liquids,[BuPy]BF4 was proved to be the best co-solvent. The s value of TsOH and the yield of TsCl at optimal[BuPy]BF4 content (2 (wt)%) were 12.5 and 87.36%, respectively. The influence of the molar ratio of feedstocks, reaction temperature and reaction time on the yield of TsCl were also investigated. The optimum reaction conditions that determined by orthogonal experiment were as follows:n(ClSO3H):n(TsOH)=1.5:1, reaction temperature is 25℃, reaction time is 2h.
Four kinds of different ionic liquids were investigated as novel co-solvents for synthesis of p-toluene sulfonyl chloride (TsCl) with p-toluene sulfonyl acid (TsOH) and chlorosulfonic acid (ClSO3H) as feedstocks in ethylidene chloride. The effect of ionic liquids on solubility ratio (s value) of TsOH in ethylidene chloride and sulphuric acid, as well as the yield of TsCl was studied particularly. The results showed that the s value of TsOH was significantly enhanced with increasing of ionic liquid amount. The yield of TsCl thus was also increased, correspondingly. Among four screened ionic liquids,[BuPy]BF4 was proved to be the best co-solvent. The s value of TsOH and the yield of TsCl at optimal[BuPy]BF4 content (2 (wt)%) were 12.5 and 87.36%, respectively. The influence of the molar ratio of feedstocks, reaction temperature and reaction time on the yield of TsCl were also investigated. The optimum reaction conditions that determined by orthogonal experiment were as follows:n(ClSO3H):n(TsOH)=1.5:1, reaction temperature is 25℃, reaction time is 2h.
2016, 79(9): 864-875
Abstract:
Although covalent bond strengths in small molecules can be obtained by Gaussian calculations, or available in some databases and handbooks, analysis of the influencing factors on covalent bond is still very important in chemistry teaching. The bond strength has close relations to both the bonding atoms and the bonding surrounding, the former include atomic radii, bonding symmetry, bonding orbitals, relativistic effect, electronegativity, bonding multiplicity, feedback effect, lone pair effect, and so on; the latter include bonding tension effect, delocalization effect, secondary bond effect, induction effect, steric effect, and so on. By this analysis, we can guide students to realize the variation tendency of the covalent bond energies. The influence of the bonding atom and the bonding surrounding on the covalent bond strength are discussed, and the application of this analyzing approach in chemistry teaching are introduced.
Although covalent bond strengths in small molecules can be obtained by Gaussian calculations, or available in some databases and handbooks, analysis of the influencing factors on covalent bond is still very important in chemistry teaching. The bond strength has close relations to both the bonding atoms and the bonding surrounding, the former include atomic radii, bonding symmetry, bonding orbitals, relativistic effect, electronegativity, bonding multiplicity, feedback effect, lone pair effect, and so on; the latter include bonding tension effect, delocalization effect, secondary bond effect, induction effect, steric effect, and so on. By this analysis, we can guide students to realize the variation tendency of the covalent bond energies. The influence of the bonding atom and the bonding surrounding on the covalent bond strength are discussed, and the application of this analyzing approach in chemistry teaching are introduced.
2016, 79(9): 876-879
Abstract:
In volumetric analysis, error of titration determines the reliability of the analysis method. According to the proton balance equation, the precise expressions of the end point error can be derived. The expressions were calculated using the concentration of the substance at the beginning of the titration rather than the end point. The expressions were calculated with the pH at the end point of titration, and not need to calculate the pH at stoichiometric point. The expressions are universal, which can effectively reduce the difficulty of learning and memory, and improve the accuracy of the calculation results.
In volumetric analysis, error of titration determines the reliability of the analysis method. According to the proton balance equation, the precise expressions of the end point error can be derived. The expressions were calculated using the concentration of the substance at the beginning of the titration rather than the end point. The expressions were calculated with the pH at the end point of titration, and not need to calculate the pH at stoichiometric point. The expressions are universal, which can effectively reduce the difficulty of learning and memory, and improve the accuracy of the calculation results.
