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2019 Volume 82 Issue 6
2019, 82(6): 483-487
Abstract:
Lithium/carbon fluorides (Li/CFx) battery, owing to its high energy density (2203 Wh/kg) of solid cathode systems, has attracted much attention and been applied in many fields. The optimal design of Li/CFx primary batteries with high power density was introduced in this paper. The precursors of fluorinated carbon materials, fluorination methods, surface modification of fluorinated carbon materials, electrode structure design and other factors are discussed in detail. Based on our work and recent studies by other groups, important and comprehensive guidelines for further research and development direction of lithium/carbon fluorides batteries are provided.
Lithium/carbon fluorides (Li/CFx) battery, owing to its high energy density (2203 Wh/kg) of solid cathode systems, has attracted much attention and been applied in many fields. The optimal design of Li/CFx primary batteries with high power density was introduced in this paper. The precursors of fluorinated carbon materials, fluorination methods, surface modification of fluorinated carbon materials, electrode structure design and other factors are discussed in detail. Based on our work and recent studies by other groups, important and comprehensive guidelines for further research and development direction of lithium/carbon fluorides batteries are provided.
2019, 82(6): 488-495
Abstract:
Styrene oxide and benzaldehyde are widely used in industrial production and organic synthesis as important chemical raw materials and intermediates. In this article, the production and research backgrounds of styrene oxide and benzaldehyde were first reviewed. The latest research progress was outlined. Based on the production of styrene and a raw material for producing styrene oxide and benzaldehyde, seven types of Ag series of catalysts used to catalyze the epoxidation of styrene were summarized, and their preparation method, structural characteristics and catalytic performance were introduced. Then their application in styrene catalytic reactions was described.
Styrene oxide and benzaldehyde are widely used in industrial production and organic synthesis as important chemical raw materials and intermediates. In this article, the production and research backgrounds of styrene oxide and benzaldehyde were first reviewed. The latest research progress was outlined. Based on the production of styrene and a raw material for producing styrene oxide and benzaldehyde, seven types of Ag series of catalysts used to catalyze the epoxidation of styrene were summarized, and their preparation method, structural characteristics and catalytic performance were introduced. Then their application in styrene catalytic reactions was described.
2019, 82(6): 496-503
Abstract:
A variety of different signaling mechanisms have been employed to design fluorescent sensors and probes. Among them, the C=N isomerization process has attracted much attention in recent years. Herein, the progress during the last decade in fluorescent probes for cations, anions and neutral molecules based on C=N mechanism is summarized. The further development tendency of this mechanism is also prospected in the end.
A variety of different signaling mechanisms have been employed to design fluorescent sensors and probes. Among them, the C=N isomerization process has attracted much attention in recent years. Herein, the progress during the last decade in fluorescent probes for cations, anions and neutral molecules based on C=N mechanism is summarized. The further development tendency of this mechanism is also prospected in the end.
2019, 82(6): 504-509
Abstract:
In this paper, A hemicyanine dye (HCy) which contains benzaldehyde structure was prepared by one-step reaction of 2-methylbenzothiazole with terephthalaldehyde, Its structure was characterized by 1H NMR and MS. The recognition of HCy to HSO3- in both aqueous and DMSO solution, and the effects on the spectral properties of HCy caused by different environments were tested. The toxicity of HCy to hepatocytes (HL-7702) and hepatoma cells (HepG2) were also investigated. The results showed that this benzaldehyde-based fluorescent probe exhibits excellent selectivity and sensitivity to bisulfite in both aqueous and DMSO solution. In addition, our results also showed that HCy can respond to GSH specifically, and HCy has excellent biocompatibility in the cell experiments.
In this paper, A hemicyanine dye (HCy) which contains benzaldehyde structure was prepared by one-step reaction of 2-methylbenzothiazole with terephthalaldehyde, Its structure was characterized by 1H NMR and MS. The recognition of HCy to HSO3- in both aqueous and DMSO solution, and the effects on the spectral properties of HCy caused by different environments were tested. The toxicity of HCy to hepatocytes (HL-7702) and hepatoma cells (HepG2) were also investigated. The results showed that this benzaldehyde-based fluorescent probe exhibits excellent selectivity and sensitivity to bisulfite in both aqueous and DMSO solution. In addition, our results also showed that HCy can respond to GSH specifically, and HCy has excellent biocompatibility in the cell experiments.
2019, 82(6): 510-515
Abstract:
The 2-(benzothiazol-2-yl)-5-(N, N-diethylamino)phenol derivative (probe L) was synthesized using 4-N, N-diethylamino salicylaldehyde as the starting material, and its structure was characterized. In DMSO/PBS (3:7, v/v, pH=7.4) solution, probe L can recognize H2S with high selectivity and fluorescence "turn-on" responding, and fluorescence color was changed from non-fluoresce to blue strong fluorescence by irradiation with a 365 nm UV lamp. The experimental results indicated that the detection limit of probe L is 2.05×10-6mol/L, and the pH range of L recognition for H2S is 6~9. The probe L can be used to detect H2S in real water samples.
The 2-(benzothiazol-2-yl)-5-(N, N-diethylamino)phenol derivative (probe L) was synthesized using 4-N, N-diethylamino salicylaldehyde as the starting material, and its structure was characterized. In DMSO/PBS (3:7, v/v, pH=7.4) solution, probe L can recognize H2S with high selectivity and fluorescence "turn-on" responding, and fluorescence color was changed from non-fluoresce to blue strong fluorescence by irradiation with a 365 nm UV lamp. The experimental results indicated that the detection limit of probe L is 2.05×10-6mol/L, and the pH range of L recognition for H2S is 6~9. The probe L can be used to detect H2S in real water samples.
2019, 82(6): 516-521
Abstract:
Based on the consideration of economy and environmental protection, a new method for the synthesis of a series of quinolinamide derivatives from quinolinecarboxaldehyde and aromatic amines has been developed by using an inexpensive and easy-to-handle base as the promoter at room temperature. The effects of solvents, bases and substrates molar ratios on the reaction were examined to obtain the optimal reaction conditions, and a possible reaction mechanism was proposed. The reaction possesses many advantages such as mild conditions, simple treatment, good yields, and environmental friendliness.
Based on the consideration of economy and environmental protection, a new method for the synthesis of a series of quinolinamide derivatives from quinolinecarboxaldehyde and aromatic amines has been developed by using an inexpensive and easy-to-handle base as the promoter at room temperature. The effects of solvents, bases and substrates molar ratios on the reaction were examined to obtain the optimal reaction conditions, and a possible reaction mechanism was proposed. The reaction possesses many advantages such as mild conditions, simple treatment, good yields, and environmental friendliness.
2019, 82(6): 522-526
Abstract:
1, 2-Bis-(1-H-benzoimidazol-2-yl) ethanol(HbbImet) was synthesized by DL-malic acid and o-phenylenediamine in ethylene glycol in different hydrochloride forms. The corrosion inhibition performance of HbbImet for Q235 steel was tested by mass loss method, polarization curve, electrochemical impedance spectroscopy (EIS) in 0.5 mol/L HCl solution, and the corrosion inhibition mechanism of HbbImet on Q235 steel was also discussed. The results showed that the inhibition efficiency increased with the increasing of HbbImet concentration at 25℃, and the inhibition efficiency can up to 92.23% when the concentration of HbbImet is 120mg/L. The addition of HbbImet significantly increases the apparent activation energy of the corrosion reaction and effectively inhibits the progress of the corrosion reaction. It is a mix-type corrosion inhibitor mainly controlling the hydrogen evolution process of the cathode.
1, 2-Bis-(1-H-benzoimidazol-2-yl) ethanol(HbbImet) was synthesized by DL-malic acid and o-phenylenediamine in ethylene glycol in different hydrochloride forms. The corrosion inhibition performance of HbbImet for Q235 steel was tested by mass loss method, polarization curve, electrochemical impedance spectroscopy (EIS) in 0.5 mol/L HCl solution, and the corrosion inhibition mechanism of HbbImet on Q235 steel was also discussed. The results showed that the inhibition efficiency increased with the increasing of HbbImet concentration at 25℃, and the inhibition efficiency can up to 92.23% when the concentration of HbbImet is 120mg/L. The addition of HbbImet significantly increases the apparent activation energy of the corrosion reaction and effectively inhibits the progress of the corrosion reaction. It is a mix-type corrosion inhibitor mainly controlling the hydrogen evolution process of the cathode.
2019, 82(6): 527-533
Abstract:
1-Alkyl-4-amino-1, 2, 4-triazolium nitrate energetic ionic liquids (EILs) were synthesized and characterized by 1H NMR and FT-IR. Their interaction energies of ion pairs and standard molar volume were calculated by DFT/B3LYP/6-311+G(d, p). The saturated vapor pressure of different molar ratio (xA, EtOH=0.984, 0.996, 0.999 and 1.000) of the [RATZ]NO3-EtOH mixed solution were measured within the temperature range of 303 K~353 K. The relationship between the saturated vapor pressure of [RATZ]NO3-EtOH, vapor pressure and molar enthalpy of vaporization of [RATZ]NO3 and temperature (303 to 353) K, molecular structure, and the interaction energies of ion pairs were discussed. The results showed that the saturated vapor pressure of [RATZ]NO3-EtOH mixed solution increases with the increase of temperature, the decrease of interionic energy and the increase of cation size, and its boiling point is higher than that of pure solvent (EtOH). The vapor pressure of vaporization of [RATZ]NO3 are lower than 250 mPa at 303 K~353 K, indicating that the energetic ionic liquid is non-volatile. Finally, the reason of the molar enthalpy of vaporization of [RATZ]NO3 decreases with the elongation of the alkyl chain length on cation is explained by the cation size and interaction energies of ion pairs through calculation.
1-Alkyl-4-amino-1, 2, 4-triazolium nitrate energetic ionic liquids (EILs) were synthesized and characterized by 1H NMR and FT-IR. Their interaction energies of ion pairs and standard molar volume were calculated by DFT/B3LYP/6-311+G(d, p). The saturated vapor pressure of different molar ratio (xA, EtOH=0.984, 0.996, 0.999 and 1.000) of the [RATZ]NO3-EtOH mixed solution were measured within the temperature range of 303 K~353 K. The relationship between the saturated vapor pressure of [RATZ]NO3-EtOH, vapor pressure and molar enthalpy of vaporization of [RATZ]NO3 and temperature (303 to 353) K, molecular structure, and the interaction energies of ion pairs were discussed. The results showed that the saturated vapor pressure of [RATZ]NO3-EtOH mixed solution increases with the increase of temperature, the decrease of interionic energy and the increase of cation size, and its boiling point is higher than that of pure solvent (EtOH). The vapor pressure of vaporization of [RATZ]NO3 are lower than 250 mPa at 303 K~353 K, indicating that the energetic ionic liquid is non-volatile. Finally, the reason of the molar enthalpy of vaporization of [RATZ]NO3 decreases with the elongation of the alkyl chain length on cation is explained by the cation size and interaction energies of ion pairs through calculation.
2019, 82(6): 534-541, 503
Abstract:
The mechanism for the reaction between NO2 and HSO was investigated at the CCSD(T)/aug-cc-pVTZ //B3LYP/aug-cc-pVTZ level on both the singlet and triplet potential energy surfaces (PESs). The results showed that there are three hydrogen abstraction reaction channels on both singlet [R1 HN(O)O+1SO), R2 (cis-HONO+1SO), and R3 (trans-HONO+1SO)] and triplet [R6 (HN(O)O+3SO), R7(cis-HONO+3SO), and R8(trans-HONO+3SO)] PESs, as well as two oxygen abstraction reaction channels on both singlet [R4 (NO+HS(O)O)and R5(H+SO2+NO)] and triplet [R9(HS(O)O+NO) and R10 (H+SO2+NO)] on the triplet PESs. Among these channels, Channel R2 (cis-HONO+1SO) on the singlet PESs is the favorable channel. The rate constants of above reaction channels were evaluated using classical transition state theory (TST) and Wigner correction. The calculated results showed that the reaction channel of cis-HONO+SO formations is favorable and its rate constant, at 298K, is 7.78×10-13cm3·molecule-1·s-1, which is in good agreement with experimental value (9.6×10-12cm3·molecule-1·s-1). Water molecule catalyzed R2 (cis-HONO+1SO) occurs through two different channels of NO2+H2O…HSO and NO2+H2O…HSO (HSO+NO2…H2O), where the barriers of the two channels respectively are enhanced by 49.97 kcal·mol-1 and 20.67 kcal·mol-1 than that of the naked reaction of R2, indicating that the effect of water molecules on the NO2+HSO reaction can be neglected in the actual atmospheric environment.
The mechanism for the reaction between NO2 and HSO was investigated at the CCSD(T)/aug-cc-pVTZ //B3LYP/aug-cc-pVTZ level on both the singlet and triplet potential energy surfaces (PESs). The results showed that there are three hydrogen abstraction reaction channels on both singlet [R1 HN(O)O+1SO), R2 (cis-HONO+1SO), and R3 (trans-HONO+1SO)] and triplet [R6 (HN(O)O+3SO), R7(cis-HONO+3SO), and R8(trans-HONO+3SO)] PESs, as well as two oxygen abstraction reaction channels on both singlet [R4 (NO+HS(O)O)and R5(H+SO2+NO)] and triplet [R9(HS(O)O+NO) and R10 (H+SO2+NO)] on the triplet PESs. Among these channels, Channel R2 (cis-HONO+1SO) on the singlet PESs is the favorable channel. The rate constants of above reaction channels were evaluated using classical transition state theory (TST) and Wigner correction. The calculated results showed that the reaction channel of cis-HONO+SO formations is favorable and its rate constant, at 298K, is 7.78×10-13cm3·molecule-1·s-1, which is in good agreement with experimental value (9.6×10-12cm3·molecule-1·s-1). Water molecule catalyzed R2 (cis-HONO+1SO) occurs through two different channels of NO2+H2O…HSO and NO2+H2O…HSO (HSO+NO2…H2O), where the barriers of the two channels respectively are enhanced by 49.97 kcal·mol-1 and 20.67 kcal·mol-1 than that of the naked reaction of R2, indicating that the effect of water molecules on the NO2+HSO reaction can be neglected in the actual atmospheric environment.
2019, 82(6): 542-548
Abstract:
Polyethylene glycol vinylbenzyl ether (PEG-VBE) and polyethylene glycol di(vinylbenzyl) ether (PEG-DVBE) are important polymerizable PEG-derivatives, which have good applications in the fields of catalyst support and functional polymers. In this paper, a series of PEG-VBE and PEG-DVBE were prepared by reaction of vinyl benzyl chloride (VBC) with ethylene glycol, diethylene glycol, triethylene glycol, PEG400, PEG600, and PEG1500 using KOH as base. The conversion rate of VBC is more than 96%, and the separation yield of PEG-VBE is in range of 32%~93%. The products were characterized by 1H NMR、ESI-HRMS and FT-IR. Using PEG based polymer as microreactor, the esterification of benzoic acid and methanol was investigated. The combination of PEG based polymer with sulfuric acid has very good catalytic activity on the esterification. At the optimized condition, the conversion of benzoic acid is up to 99%. The catalytic activity is barely decreased after five cycles.
Polyethylene glycol vinylbenzyl ether (PEG-VBE) and polyethylene glycol di(vinylbenzyl) ether (PEG-DVBE) are important polymerizable PEG-derivatives, which have good applications in the fields of catalyst support and functional polymers. In this paper, a series of PEG-VBE and PEG-DVBE were prepared by reaction of vinyl benzyl chloride (VBC) with ethylene glycol, diethylene glycol, triethylene glycol, PEG400, PEG600, and PEG1500 using KOH as base. The conversion rate of VBC is more than 96%, and the separation yield of PEG-VBE is in range of 32%~93%. The products were characterized by 1H NMR、ESI-HRMS and FT-IR. Using PEG based polymer as microreactor, the esterification of benzoic acid and methanol was investigated. The combination of PEG based polymer with sulfuric acid has very good catalytic activity on the esterification. At the optimized condition, the conversion of benzoic acid is up to 99%. The catalytic activity is barely decreased after five cycles.
2019, 82(6): 549-554
Abstract:
The existence of amorphous ploy(D, L-Lactic acid) (PDLLA) will influence the crystallization behavior of Ploy(L-Lactic acid) (PLLA). In this work, the differential scanning calorimeter (DSC) and polarizing optical microscope (POM) were used to investigate the crystallization behavior of PLLA/PDLLA blends with different molecular weights and compositions. When the molecular weight of PDLLA is small, the spherulite characteristics of PLLA are obviously destroyed. When the molecular weight of blending PDLLA is large, PLLA is more likely to maintain the spherulitic characteristics, and it is easy to form a ring-shaped spherulitic morphology. It is depending on the degree of matching between the crystallization rate and the diffusion rate of the amorphous component. The maximum growth rate appears at lower temperature while blending with PDLLA that have smaller molecular weight.
The existence of amorphous ploy(D, L-Lactic acid) (PDLLA) will influence the crystallization behavior of Ploy(L-Lactic acid) (PLLA). In this work, the differential scanning calorimeter (DSC) and polarizing optical microscope (POM) were used to investigate the crystallization behavior of PLLA/PDLLA blends with different molecular weights and compositions. When the molecular weight of PDLLA is small, the spherulite characteristics of PLLA are obviously destroyed. When the molecular weight of blending PDLLA is large, PLLA is more likely to maintain the spherulitic characteristics, and it is easy to form a ring-shaped spherulitic morphology. It is depending on the degree of matching between the crystallization rate and the diffusion rate of the amorphous component. The maximum growth rate appears at lower temperature while blending with PDLLA that have smaller molecular weight.
2019, 82(6): 555-558
Abstract:
Cu3(BTC)2 (BTC:1, 3, 5-benzenetricarboxylate) as cocatalyst is an effective and reusable heterogeneous catalyst, exhibiting enormous potential applications in heterogeneous catalysis. The CuBTC was evaluated for aerobic oxidation of benzylic alcohols in copper and TEMPO catalyst system. The aerobic oxidation of benzylic alcohols to aldehydes was performed with CuBTC catalyst. It is important that the catalyst system has a great selectivity and displays a preference for the primary versus secondary benzylalcohol. Comparison with copper acetate as a soluble, immobilization of the Cu(Ⅱ) in the rigid crystal structure of Cu3(BTC)2 does not diminish the intrinsic catalytic activity of this transition metal ion. But carboxylic acid can cause catalyst poisoning, therefore, CuBTC is not suitable for the reaction system in which carboxylic acid is present in raw materials, products or by-products.
Cu3(BTC)2 (BTC:1, 3, 5-benzenetricarboxylate) as cocatalyst is an effective and reusable heterogeneous catalyst, exhibiting enormous potential applications in heterogeneous catalysis. The CuBTC was evaluated for aerobic oxidation of benzylic alcohols in copper and TEMPO catalyst system. The aerobic oxidation of benzylic alcohols to aldehydes was performed with CuBTC catalyst. It is important that the catalyst system has a great selectivity and displays a preference for the primary versus secondary benzylalcohol. Comparison with copper acetate as a soluble, immobilization of the Cu(Ⅱ) in the rigid crystal structure of Cu3(BTC)2 does not diminish the intrinsic catalytic activity of this transition metal ion. But carboxylic acid can cause catalyst poisoning, therefore, CuBTC is not suitable for the reaction system in which carboxylic acid is present in raw materials, products or by-products.
2019, 82(6): 559-562
Abstract:
3-Amino-5, 7-dihydroxy-4-methyl coumarin (4) is a new important organic intermediate, which can be used to synthesize various bioactive agents. In this work, compound 4 was synthesized in one pot from phloroglucinol and ethyl 2-acetylamino acetoacetate (2), which was prepared from ethyl acetoacetate by oxime formation, reduction and acylation successively, by Pechmann condensation and deacetylation in series under the catalysis of BF3·Et2O. All intermediates and the final product were confirmed by 1H NMR、13C NMR and MS. This method has considerable advantages in terms of the use of easily available raw material, less steps, simple operation, mild reaction conditions and high yield.
3-Amino-5, 7-dihydroxy-4-methyl coumarin (4) is a new important organic intermediate, which can be used to synthesize various bioactive agents. In this work, compound 4 was synthesized in one pot from phloroglucinol and ethyl 2-acetylamino acetoacetate (2), which was prepared from ethyl acetoacetate by oxime formation, reduction and acylation successively, by Pechmann condensation and deacetylation in series under the catalysis of BF3·Et2O. All intermediates and the final product were confirmed by 1H NMR、13C NMR and MS. This method has considerable advantages in terms of the use of easily available raw material, less steps, simple operation, mild reaction conditions and high yield.
2019, 82(6): 563-565, 533
Abstract:
Among the mainstream analytical chemistry textbooks, the hydrogen ion concentration of a monoprotic weak acid solution can be estimated by approximation formulas\begin{document}${\left[ {{{\rm{H}}^ + }} \right]_{{\rm{AV}}1}} = \frac{1}{2}\left({ - {K_{\rm{a}}} + \sqrt {K_{\rm{a}}^2 + 4c{K_{\rm{a}}}} } \right)$\end{document} \begin{document}${\left[ {{{\rm{H}}^ + }} \right]_{{\rm{AV}}2}} = \sqrt {c{K_{\rm{a}}}} $\end{document}
Among the mainstream analytical chemistry textbooks, the hydrogen ion concentration of a monoprotic weak acid solution can be estimated by approximation formulas
2019, 82(6): 566-575, 515
Abstract:
Chemistry and physics interacted considerably on the problem of chemical bond during the early twentieth century. Among them, the influence of the theory put forward by American chemist Pauling in the early 1930s is the most significant. Pauling's work had several origins from both chemistry and physics, ranging from classical structural chemistry in late nineteenth century to quantum mechanics just articulated then, and those training him directly including the chemical bond theory of Lewis, X-ray crystallography, and physical chemistry. Physical origins have more prominent influence than chemical, while both sorts regard experiment, and theoretical aspects show more convergence to the empirical than the reverse.
Chemistry and physics interacted considerably on the problem of chemical bond during the early twentieth century. Among them, the influence of the theory put forward by American chemist Pauling in the early 1930s is the most significant. Pauling's work had several origins from both chemistry and physics, ranging from classical structural chemistry in late nineteenth century to quantum mechanics just articulated then, and those training him directly including the chemical bond theory of Lewis, X-ray crystallography, and physical chemistry. Physical origins have more prominent influence than chemical, while both sorts regard experiment, and theoretical aspects show more convergence to the empirical than the reverse.
