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2019 Volume 82 Issue 3
2019, 82(3): 195-201
Abstract:
Covalent organic frameworks (COFs) are crystalline porous polymers formed by covalent bonding of small organic molecules. Unlike typical linear polymers, COFs offer fine control over their skeletons in two and three dimensions, which enables the synthesis of rigid porous structures with high regularity and tunable chemical and physical properties. The nanoscale channels and voids in COFs provide an ideal environment for molecular storage, release and separation, endowing them great potential in energy adsorption, separation, and catalysis. This article reviews the progress in COFs, including the synthesis strategies, the applications in separation field as well as outlook of their future developments.
Covalent organic frameworks (COFs) are crystalline porous polymers formed by covalent bonding of small organic molecules. Unlike typical linear polymers, COFs offer fine control over their skeletons in two and three dimensions, which enables the synthesis of rigid porous structures with high regularity and tunable chemical and physical properties. The nanoscale channels and voids in COFs provide an ideal environment for molecular storage, release and separation, endowing them great potential in energy adsorption, separation, and catalysis. This article reviews the progress in COFs, including the synthesis strategies, the applications in separation field as well as outlook of their future developments.
2019, 82(3): 202-208, 213
Abstract:
Metal-organic frameworks (MOFs) are a class of materials that are formed by metal nodes or secondary building units (SBUs) and organic ligands that are self-assembled through coordination bonds. They have been extensively studied for their rich structural chemistry and potential applications in numerous area. Recent studies on luminescent MOFs in both bulk and nanoparticle forms have shown that these materials possess excellent luminescence emission properties that can be utilized to effectively detect solvent molecules, heavy metal ions, aflatoxin, nitrobenzene explosives, iodide ions and so on. In addition, developing highly sensitive, selective, fast-responding and fully reversible sensors for toxic substances and explosives' detection is in great demand for the homeland security, environmental safety and other humanitarian concerns. This paper mainly discusses the possible mechanisms and development prospects of MOF materials as fluorescent sensors.
Metal-organic frameworks (MOFs) are a class of materials that are formed by metal nodes or secondary building units (SBUs) and organic ligands that are self-assembled through coordination bonds. They have been extensively studied for their rich structural chemistry and potential applications in numerous area. Recent studies on luminescent MOFs in both bulk and nanoparticle forms have shown that these materials possess excellent luminescence emission properties that can be utilized to effectively detect solvent molecules, heavy metal ions, aflatoxin, nitrobenzene explosives, iodide ions and so on. In addition, developing highly sensitive, selective, fast-responding and fully reversible sensors for toxic substances and explosives' detection is in great demand for the homeland security, environmental safety and other humanitarian concerns. This paper mainly discusses the possible mechanisms and development prospects of MOF materials as fluorescent sensors.
2019, 82(3): 209-213
Abstract:
Mesoporous material is a kind of material with a large specific surface area and a highly ordered pore structure. Functionalized mesoporous materials are materials with different functions modified by mesoporous materials, which are widely used in environmental field due to their excellent adsorption and catalytic properties. This paper reviews the preparation of functional mesoporous materials, including the introduction of functional groups, doping metals, and acid modification. The characteristics and application prospects of functionalized mesoporous materials under several preparation methods are discussed. The research progress of functionalized mesoporous materials in the fields of heavy metals, organic pollutants, dyes, CO2 and catalysis is highlighted. Finally, the application prospects and development trends of functionalized mesoporous materials in the future are prospected, and it is expected to provide reference and direction for the development of functional mesoporous materials.
Mesoporous material is a kind of material with a large specific surface area and a highly ordered pore structure. Functionalized mesoporous materials are materials with different functions modified by mesoporous materials, which are widely used in environmental field due to their excellent adsorption and catalytic properties. This paper reviews the preparation of functional mesoporous materials, including the introduction of functional groups, doping metals, and acid modification. The characteristics and application prospects of functionalized mesoporous materials under several preparation methods are discussed. The research progress of functionalized mesoporous materials in the fields of heavy metals, organic pollutants, dyes, CO2 and catalysis is highlighted. Finally, the application prospects and development trends of functionalized mesoporous materials in the future are prospected, and it is expected to provide reference and direction for the development of functional mesoporous materials.
2019, 82(3): 214-220
Abstract:
Synthetic ammonia is a low-cost chemical material. It is a novel clean energy with broad application prospects and possesses high energy density and octane value, convenient conditions for storage and transportation, and combustion without CO2 emissions. Ammonia can replace gasoline, diesel and other fossil fuels and supply clean fuel for automotive engines, moreover, it can provide hydrogen energy for vehicle fuel cells through catalytic decomposition. Being the ideal alternative to traditional petroleum fuels, ammonia offers another fuel choice for solving the problems of environmental pollution and energy shortage. This paper mainly focuses on the advantages and maneuverability of ammonia used as engine fuel and fuel cell raw material in automotive power source, and the related research progress at home and abroad. The research progress and limitation of the catalytic system for ammonia decomposition and the research status of synthetic ammonia were introduced.
Synthetic ammonia is a low-cost chemical material. It is a novel clean energy with broad application prospects and possesses high energy density and octane value, convenient conditions for storage and transportation, and combustion without CO2 emissions. Ammonia can replace gasoline, diesel and other fossil fuels and supply clean fuel for automotive engines, moreover, it can provide hydrogen energy for vehicle fuel cells through catalytic decomposition. Being the ideal alternative to traditional petroleum fuels, ammonia offers another fuel choice for solving the problems of environmental pollution and energy shortage. This paper mainly focuses on the advantages and maneuverability of ammonia used as engine fuel and fuel cell raw material in automotive power source, and the related research progress at home and abroad. The research progress and limitation of the catalytic system for ammonia decomposition and the research status of synthetic ammonia were introduced.
2019, 82(3): 221-230
Abstract:
Metalloproteins are proteins containing metal ions, they play important roles in biology system due to their special catalytic activity. A lot of study has been done to elucidate their structural and functional mechanism. Based on the active site mimic of existing metalloprotein, artificially designed metalloproteins with specific structure and function can be achieved through computer aided protein design method. In this paper, research progress in computer aided metalloprotein design and engineering was reviewed. The general principle for introducing metal ion binding site and protein activity enhancement was summarized. We also presented current problems and challenges in this field, along with future directions and probable breakthrough point.
Metalloproteins are proteins containing metal ions, they play important roles in biology system due to their special catalytic activity. A lot of study has been done to elucidate their structural and functional mechanism. Based on the active site mimic of existing metalloprotein, artificially designed metalloproteins with specific structure and function can be achieved through computer aided protein design method. In this paper, research progress in computer aided metalloprotein design and engineering was reviewed. The general principle for introducing metal ion binding site and protein activity enhancement was summarized. We also presented current problems and challenges in this field, along with future directions and probable breakthrough point.
2019, 82(3): 231-236
Abstract:
The reaction-controlled phase-ransfer catalysis has the advantages of homogeneous and heterogeneous catalysis. It can resolve the problems of low catalytic activity and recovery difficulty of the catalyst, which meets environmentally friendly requirements. So, the reaction-controlled phase-transfer catalysis has been receiving much attention. The reaction-controlled phase-transfer phenomenon is closely related to the structures of catalyst anion and cation, and reaction conditions such as solvent. In this paper, the structural features of anion and cation of reaction-controlled phase-transfer catalysts in the widely used reactions are reviewed. Finally, the possible problems and innovation of the current reaction-controlled phase-transfer catalytic systems are proposed, and the development prospects are also forecasted.
The reaction-controlled phase-ransfer catalysis has the advantages of homogeneous and heterogeneous catalysis. It can resolve the problems of low catalytic activity and recovery difficulty of the catalyst, which meets environmentally friendly requirements. So, the reaction-controlled phase-transfer catalysis has been receiving much attention. The reaction-controlled phase-transfer phenomenon is closely related to the structures of catalyst anion and cation, and reaction conditions such as solvent. In this paper, the structural features of anion and cation of reaction-controlled phase-transfer catalysts in the widely used reactions are reviewed. Finally, the possible problems and innovation of the current reaction-controlled phase-transfer catalytic systems are proposed, and the development prospects are also forecasted.
2019, 82(3): 237-242
Abstract:
In this article the relationship between the surface tension and temperature for six pure liquids were studied quantitatively, and the heat released by the phase transition of these liquids from bulk to surface has been further predicted. We elucidate that the fundamental cause of exothermicity is that the entropy is reduced due to that molecules are arranged in a more ordered way in the surface phase. The relationships between the surface tension and concentrations of CaCl2 and K2CO3 aqueous solutions were also investigated and the simulated results were in very close agreement with the experimental data. Meanwhile, we also estimated the surface layer thickness of 16 strong electrolyte solutions at given β values, and a theoretical explanation for the phenomenon of the surface layer thickening of solutions was given.
In this article the relationship between the surface tension and temperature for six pure liquids were studied quantitatively, and the heat released by the phase transition of these liquids from bulk to surface has been further predicted. We elucidate that the fundamental cause of exothermicity is that the entropy is reduced due to that molecules are arranged in a more ordered way in the surface phase. The relationships between the surface tension and concentrations of CaCl2 and K2CO3 aqueous solutions were also investigated and the simulated results were in very close agreement with the experimental data. Meanwhile, we also estimated the surface layer thickness of 16 strong electrolyte solutions at given β values, and a theoretical explanation for the phenomenon of the surface layer thickening of solutions was given.
2019, 82(3): 243-250
Abstract:
Molecular imprinted polymers (MIPs) were prepared on polyethylenimine (PEI) grafted multi-wall carbon nanotube (MWCNT-PEI) by using propyl gallate (PG) as target molecule, ethylene glycol diglycidyl ether as cross-linker. The molecular imprinted electrochemical sensor (MIES) for PG detection was then constructed by dropping the obtained MIPs onto the surface of glassy carbon electrode (GCE). The obtained materials were characterized and measured by FTIR, XRD, CV, EIS and DPV. The conductivity, linear response, specificity, stability and repeatability of the sensor for PG detection were investigated in detail. The constructed MIES exhibited excellent linear responses to PG in the range of 1×10-8 to 1×10-5 mol·L-1, with a detection limit of 2.5×10-9 mol·L-1. As a result, the recovery of PG in real samples was about 95%~98%.
Molecular imprinted polymers (MIPs) were prepared on polyethylenimine (PEI) grafted multi-wall carbon nanotube (MWCNT-PEI) by using propyl gallate (PG) as target molecule, ethylene glycol diglycidyl ether as cross-linker. The molecular imprinted electrochemical sensor (MIES) for PG detection was then constructed by dropping the obtained MIPs onto the surface of glassy carbon electrode (GCE). The obtained materials were characterized and measured by FTIR, XRD, CV, EIS and DPV. The conductivity, linear response, specificity, stability and repeatability of the sensor for PG detection were investigated in detail. The constructed MIES exhibited excellent linear responses to PG in the range of 1×10-8 to 1×10-5 mol·L-1, with a detection limit of 2.5×10-9 mol·L-1. As a result, the recovery of PG in real samples was about 95%~98%.
2019, 82(3): 251-257
Abstract:
In this paper, the molecularly imprinted assembly system of L-phenylalanine (L-Phe) as template molecule, 1-vinyl-3-carboxymethylimidazolium chloride ([VIM]Cl), methacrylic acid (MAA) or 4-vinyl pyridine (4-VP) as functional monomer, ethylene glycol dimethacrylate EGDMA) as cross-linking agent was analyzed via Gaussian 09 calculation software and fluorescence spectroscopy to predict a proper functional monomer, aiming to prepare L-phenylalanine-imprinted polymers (L-MIPs). The effects of functional monomers on the adsorption performance and imprinting factor of L-MIPs were studied through the experimental system, and the adsorption behaviors of L-MIP prepared with[VIM]Cl, MAA and 4-VP as functional monomers were compared finally. In addition, the morphology, surface element composition and thermal stability of L-MIP were studied by multiple characterization methods. When using[VIM]Cl as monomer, the obtained L-MIP exhibited the best imprinting effect and had good thermal stability within 300℃. The maximum imprinting factor (α) of the obtained L-MIPs could reach 3.86 and the maximum adsorption capacity of L-MIPs for L-Phe was 33.08 mg/g. Compared with the structural analogues of D-Phe, L-His and L-Trp, the recognition factor (β) were 1.24, 1.41 and 1.30 respectively. Therefore, it has important significance for selecting proper functional monomer in molecular imprinting system and predicting the performance of MIP through computer simulation.
In this paper, the molecularly imprinted assembly system of L-phenylalanine (L-Phe) as template molecule, 1-vinyl-3-carboxymethylimidazolium chloride ([VIM]Cl), methacrylic acid (MAA) or 4-vinyl pyridine (4-VP) as functional monomer, ethylene glycol dimethacrylate EGDMA) as cross-linking agent was analyzed via Gaussian 09 calculation software and fluorescence spectroscopy to predict a proper functional monomer, aiming to prepare L-phenylalanine-imprinted polymers (L-MIPs). The effects of functional monomers on the adsorption performance and imprinting factor of L-MIPs were studied through the experimental system, and the adsorption behaviors of L-MIP prepared with[VIM]Cl, MAA and 4-VP as functional monomers were compared finally. In addition, the morphology, surface element composition and thermal stability of L-MIP were studied by multiple characterization methods. When using[VIM]Cl as monomer, the obtained L-MIP exhibited the best imprinting effect and had good thermal stability within 300℃. The maximum imprinting factor (α) of the obtained L-MIPs could reach 3.86 and the maximum adsorption capacity of L-MIPs for L-Phe was 33.08 mg/g. Compared with the structural analogues of D-Phe, L-His and L-Trp, the recognition factor (β) were 1.24, 1.41 and 1.30 respectively. Therefore, it has important significance for selecting proper functional monomer in molecular imprinting system and predicting the performance of MIP through computer simulation.
2019, 82(3): 258-263
Abstract:
3-Acetyl-8-tert-butylcoumarin was synthesized and characterized by single-crystal X-ray diffraction, IR spectroscopy and UV-Vis spectroscopy. Density functional theory was used to investigate the intermolecular weak interaction in crystal, simulate spectrum and predict active site which is possible to be attacked by electrophilic or nucleophile reagent. The results showed that the molecule is almost a planar structure which exists conjugation effect. Molecules in crystal are combined by π-π stacking between layers and hydrogen bonds in chains, and the binding energy of two molecules is 17.2 and 3.9 kcal/mol respectively. The wavelength of maximum absorption in the scope of near ultraviolet and visible light is about 310nm, and molar absorption coefficient is 16000 L·mol-1·cm-1, which was caused by π-electron of benzene ring transferring to inner ester ring and the oxygen atom of aldehyde group. No. 6 carbon is the most likely site to be attacked by electrophilic reagent in benzene ring. Inner ester is able to undergo hydrolysis or aminolysis reaction. The hydrogen atoms in the benzene ring and the oxygen atoms of carbonyl groups can both form weak interaction such as hydrogen bond.
3-Acetyl-8-tert-butylcoumarin was synthesized and characterized by single-crystal X-ray diffraction, IR spectroscopy and UV-Vis spectroscopy. Density functional theory was used to investigate the intermolecular weak interaction in crystal, simulate spectrum and predict active site which is possible to be attacked by electrophilic or nucleophile reagent. The results showed that the molecule is almost a planar structure which exists conjugation effect. Molecules in crystal are combined by π-π stacking between layers and hydrogen bonds in chains, and the binding energy of two molecules is 17.2 and 3.9 kcal/mol respectively. The wavelength of maximum absorption in the scope of near ultraviolet and visible light is about 310nm, and molar absorption coefficient is 16000 L·mol-1·cm-1, which was caused by π-electron of benzene ring transferring to inner ester ring and the oxygen atom of aldehyde group. No. 6 carbon is the most likely site to be attacked by electrophilic reagent in benzene ring. Inner ester is able to undergo hydrolysis or aminolysis reaction. The hydrogen atoms in the benzene ring and the oxygen atoms of carbonyl groups can both form weak interaction such as hydrogen bond.
2019, 82(3): 264-269
Abstract:
A series of novel biquinazoline diselenide compounds were designed and synthesized with substituted 4-chloroquinazoline and sodium diselenide based on bioisosterism. Their structures were confirmed by IR, 1H NMR, 13C NMR, and elemental analyses. The antifungal activities of as-prepared compounds were evaluated by growth-rate method in vitro. Compound 1b, 1c, 1d, 1h, 1i and 1j were found to have good antibacterial activities against nine kinds of phytopathogenic fungi cell lines such as G. zeae, F. oxysporum, C. mandshurica, R. solani, T. cucumeris, S. sclerotiorum, B. cinerea, P. infestans and C. gloeosporioides. Moreover, compared with the commercial antifungal drugs Hymexazol, 1b exerted better antifungal effects on corresponding bacterial lines at 50 μg/mL.
A series of novel biquinazoline diselenide compounds were designed and synthesized with substituted 4-chloroquinazoline and sodium diselenide based on bioisosterism. Their structures were confirmed by IR, 1H NMR, 13C NMR, and elemental analyses. The antifungal activities of as-prepared compounds were evaluated by growth-rate method in vitro. Compound 1b, 1c, 1d, 1h, 1i and 1j were found to have good antibacterial activities against nine kinds of phytopathogenic fungi cell lines such as G. zeae, F. oxysporum, C. mandshurica, R. solani, T. cucumeris, S. sclerotiorum, B. cinerea, P. infestans and C. gloeosporioides. Moreover, compared with the commercial antifungal drugs Hymexazol, 1b exerted better antifungal effects on corresponding bacterial lines at 50 μg/mL.
2019, 82(3): 270-274
Abstract:
In this paper, thiophenols or mercaptans were self-coupled to form bisulfide in the presence of tribromophenone with 95% ethanol as solvent, which provided a mild, simple, green and metal-free synthesis method after traditional methods. A variety of thiophenols and mercaptans were investigated under the optimum reaction conditions. It was found that aromatic hydrocarbons containing electron withdrawing groups could obtain higher yields than that with electron-withdrawing groups, and the reaction time was also shorter. At the same time, the substrates of aliphatic and heterocyclic compounds also had relatively higher yields in this reaction.
In this paper, thiophenols or mercaptans were self-coupled to form bisulfide in the presence of tribromophenone with 95% ethanol as solvent, which provided a mild, simple, green and metal-free synthesis method after traditional methods. A variety of thiophenols and mercaptans were investigated under the optimum reaction conditions. It was found that aromatic hydrocarbons containing electron withdrawing groups could obtain higher yields than that with electron-withdrawing groups, and the reaction time was also shorter. At the same time, the substrates of aliphatic and heterocyclic compounds also had relatively higher yields in this reaction.
2019, 82(3): 275-279
Abstract:
Herein, seven novel oxiracetam derivatives were designed and synthesized upon employing pharmacophore-combination strategy. Among them, compounds 4a~4f were attained via structurally combining oxiracetam with cinnamylic acid fragment, while compounds 4g were attained via combining oxiracetam with indobufen through ester functionality. All the target compounds were biologically evaluated for the inhibitory activities of platelet aggregation induced by arachidonic acid (AA) and adenosine diphoshate (ADP) via Bron method. The results of in vitro anti-platelet aggregation activities showed that the compounds had certain anti-platelet aggregation activities, and the anti-platelet aggregation activity of compound 4f was consistent with that of the positive control indobuprofen.
Herein, seven novel oxiracetam derivatives were designed and synthesized upon employing pharmacophore-combination strategy. Among them, compounds 4a~4f were attained via structurally combining oxiracetam with cinnamylic acid fragment, while compounds 4g were attained via combining oxiracetam with indobufen through ester functionality. All the target compounds were biologically evaluated for the inhibitory activities of platelet aggregation induced by arachidonic acid (AA) and adenosine diphoshate (ADP) via Bron method. The results of in vitro anti-platelet aggregation activities showed that the compounds had certain anti-platelet aggregation activities, and the anti-platelet aggregation activity of compound 4f was consistent with that of the positive control indobuprofen.
2019, 82(3): 280-283
Abstract:
The coordination number and dissociation constant measurement of complex consisting of Iron(Ⅲ) and 4, 5-Dihydroxy-1, 3-benzenedisulfonic acid disodium salt (Tiron) has been widely employed as a teaching experiment in university. However, with varying of the ratio of iron(Ⅲ) and Tiron a distinct absorption peak shifts have been observed, indicating the non-unique complex in solution. Non-negative matrix factorization was applied to analyses the spectra data, and the characteristic spectrum and coordination number of each component were obtained. The results showed the coexistence of mono-and bis-tiron complexes of Iron(Ⅲ) in the solution, and this does challenge the rationality of this system as a teaching experiment because the coordination number should be positive integer according to the text book.
The coordination number and dissociation constant measurement of complex consisting of Iron(Ⅲ) and 4, 5-Dihydroxy-1, 3-benzenedisulfonic acid disodium salt (Tiron) has been widely employed as a teaching experiment in university. However, with varying of the ratio of iron(Ⅲ) and Tiron a distinct absorption peak shifts have been observed, indicating the non-unique complex in solution. Non-negative matrix factorization was applied to analyses the spectra data, and the characteristic spectrum and coordination number of each component were obtained. The results showed the coexistence of mono-and bis-tiron complexes of Iron(Ⅲ) in the solution, and this does challenge the rationality of this system as a teaching experiment because the coordination number should be positive integer according to the text book.
2019, 82(3): 284-287, 283
Abstract:
The bromonium ion is a cyclic intermediate in the addition of olefin and bromine. A detailed analysis on its structure will be greatly helpful not only in understanding the addition process of different olefins and bromine but also in predicting addition products. At present, there is no detailed introduction about the structure of brominium ions in the textbooks at home and abroad. As an appropriate supplement to the textbooks of organic chemistry, this paper summarized the hybridization modes of each atom and the charge distribution of atoms in three membered ring of the bromonium ion, with the subsequent nucleophilic substitution process also included.
The bromonium ion is a cyclic intermediate in the addition of olefin and bromine. A detailed analysis on its structure will be greatly helpful not only in understanding the addition process of different olefins and bromine but also in predicting addition products. At present, there is no detailed introduction about the structure of brominium ions in the textbooks at home and abroad. As an appropriate supplement to the textbooks of organic chemistry, this paper summarized the hybridization modes of each atom and the charge distribution of atoms in three membered ring of the bromonium ion, with the subsequent nucleophilic substitution process also included.
