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2020 Volume 83 Issue 9
2020, 83(9): 770-776
Abstract:
In addition to being the carrier of genetic information, DNA has attracted wide interest as a new class of material in the synthetic realm. The exploitation of the precise and programmable Watson-Crick base pairing of DNA or RNA has led to the development of exquisite nucleic acid nanostructures from one to three dimensions. Advances in computer-aided tools have also facilitated the automated design of DNA nanostructures with various sizes and shapes. The "framework nucleic acids (FNAs)" constructed in recent years provide a new method for precise organization of biological macromolecules with nanometer precision. The intrinsic biological properties and tailorable functionalities of FNAs hold great promise for physical, chemical, and biological applications. This review elaborates the concept of precise self-assembled FNAs, and summarizes the recent advances of FNAs in the field of protein precise arrangement. The unique features of FNAs that benefit the arrangement of proteins and their performance are highlighted. The challenges and opportunities of this field are also discussed.
In addition to being the carrier of genetic information, DNA has attracted wide interest as a new class of material in the synthetic realm. The exploitation of the precise and programmable Watson-Crick base pairing of DNA or RNA has led to the development of exquisite nucleic acid nanostructures from one to three dimensions. Advances in computer-aided tools have also facilitated the automated design of DNA nanostructures with various sizes and shapes. The "framework nucleic acids (FNAs)" constructed in recent years provide a new method for precise organization of biological macromolecules with nanometer precision. The intrinsic biological properties and tailorable functionalities of FNAs hold great promise for physical, chemical, and biological applications. This review elaborates the concept of precise self-assembled FNAs, and summarizes the recent advances of FNAs in the field of protein precise arrangement. The unique features of FNAs that benefit the arrangement of proteins and their performance are highlighted. The challenges and opportunities of this field are also discussed.
2020, 83(9): 777-784
Abstract:
Due to the excellent optical properties, good water solubility and good biocompatibility of carbon-based quantum dots, their applications in fluorescent sensors have attracted more and more researcher's attention, especially their excellent detection performance for metal ions, which makes them widely used in environmental detection. In order to better understand the application of carbon-based quantum dots, the synthesis of carbon quantum dots, graphene quantum dots and graphene oxide quantum dots and their application in environmental detection in recent ten years were summarized, and the applications of carbon-based quantum dots fluorescence sensor were also prospected.
Due to the excellent optical properties, good water solubility and good biocompatibility of carbon-based quantum dots, their applications in fluorescent sensors have attracted more and more researcher's attention, especially their excellent detection performance for metal ions, which makes them widely used in environmental detection. In order to better understand the application of carbon-based quantum dots, the synthesis of carbon quantum dots, graphene quantum dots and graphene oxide quantum dots and their application in environmental detection in recent ten years were summarized, and the applications of carbon-based quantum dots fluorescence sensor were also prospected.
2020, 83(9): 785-791
Abstract:
The ternary lithium ion battery mainly refers to the lithium ion battery using lithium nickel cobalt manganese oxide (NCM) or lithium nickel cobalt aluminum oxide (NCA) as the cathode electrode material. Ternary lithium ion batteries are widely used in electric vehicles, 3C electronic products and energy storage. However, the cycle life of ternary lithium ion batteries has become the biggest obstacle to its further development. Therefore, understanding the failure mechanism of ternary lithium ion battery is of great significance. The failure mechanism of ternary lithium ion battery mainly include five aspects: lattice structure change and phase transition, loss of active material, electrolyte decomposition, deintercalable lithium ion's consumption and formation of solid electrolyte interface. In this paper, the research progress in related aspects in recent years is summarized, in order to provide a more comprehensive and integrative view of capacity fading mechanisms of ternary lithium ion batteries, and the application of ternary lithium ion batteries is also prospected.
The ternary lithium ion battery mainly refers to the lithium ion battery using lithium nickel cobalt manganese oxide (NCM) or lithium nickel cobalt aluminum oxide (NCA) as the cathode electrode material. Ternary lithium ion batteries are widely used in electric vehicles, 3C electronic products and energy storage. However, the cycle life of ternary lithium ion batteries has become the biggest obstacle to its further development. Therefore, understanding the failure mechanism of ternary lithium ion battery is of great significance. The failure mechanism of ternary lithium ion battery mainly include five aspects: lattice structure change and phase transition, loss of active material, electrolyte decomposition, deintercalable lithium ion's consumption and formation of solid electrolyte interface. In this paper, the research progress in related aspects in recent years is summarized, in order to provide a more comprehensive and integrative view of capacity fading mechanisms of ternary lithium ion batteries, and the application of ternary lithium ion batteries is also prospected.
2020, 83(9): 792-798
Abstract:
N-heterocyclic carbene ligands have attracted extensive attention due to their excellent catalytic performance, and have been widely utilized in a variety of olefin polymerization reactions. According to the recent reports, N-heterocyclic carbene were briefly introduced, firstly. The recent research advances of the application in ring-opening metathesis polymerization, olefin coordination polymerization, atom transfer radical polymerization, and other polymerization were focused on. The development trends of N-heterocyclic carbene ligands in polymerization were also prospected.
N-heterocyclic carbene ligands have attracted extensive attention due to their excellent catalytic performance, and have been widely utilized in a variety of olefin polymerization reactions. According to the recent reports, N-heterocyclic carbene were briefly introduced, firstly. The recent research advances of the application in ring-opening metathesis polymerization, olefin coordination polymerization, atom transfer radical polymerization, and other polymerization were focused on. The development trends of N-heterocyclic carbene ligands in polymerization were also prospected.
2020, 83(9): 799-804
Abstract:
Chiral 4-substituted chroman skeleton is widely found in numerous bioactive natural products and their analogues. The asymmetric construction strategy of this skeleton plays a crucial role in the research of new drugs. In order to provide a reference for the asymmetric synthesis of active natural products containing this skeleton, in this paper the stereoselective forge methods of chiral 4-substituted chroman from addition reaction, hydrogenation reaction, alkylation reaction, ene/propargylation reaction, desymmetrization reaction, carbonyl α-arylation reaction and rearrangement reaction are summarized.
Chiral 4-substituted chroman skeleton is widely found in numerous bioactive natural products and their analogues. The asymmetric construction strategy of this skeleton plays a crucial role in the research of new drugs. In order to provide a reference for the asymmetric synthesis of active natural products containing this skeleton, in this paper the stereoselective forge methods of chiral 4-substituted chroman from addition reaction, hydrogenation reaction, alkylation reaction, ene/propargylation reaction, desymmetrization reaction, carbonyl α-arylation reaction and rearrangement reaction are summarized.
2020, 83(9): 805-812
Abstract:
Edible pigments have important applications in the food industry because of they can improve the appearance of food and stimulate appetite. However, if inedible pigments are added to foods instead of edible pigments, there is a risk of carcinogenesis in humans. There are seven common inedible pigments in food: Auramine O, Basic Orange Ⅱ, Acid Orange Ⅱ, Sudan Red, Rhodamine B, Lead Chrome Green and Malachite Green. At present, the national standards for detecting these inedible pigments have not been established yet. This paper summarized a variety of analysis methods for the determination of common inedible pigments in the food industry so as to provide reference for food safety supervision and inspection.
Edible pigments have important applications in the food industry because of they can improve the appearance of food and stimulate appetite. However, if inedible pigments are added to foods instead of edible pigments, there is a risk of carcinogenesis in humans. There are seven common inedible pigments in food: Auramine O, Basic Orange Ⅱ, Acid Orange Ⅱ, Sudan Red, Rhodamine B, Lead Chrome Green and Malachite Green. At present, the national standards for detecting these inedible pigments have not been established yet. This paper summarized a variety of analysis methods for the determination of common inedible pigments in the food industry so as to provide reference for food safety supervision and inspection.
2020, 83(9): 813-820
Abstract:
In this paper, the host-guest interaction of cyclopentyl substituted cucurbit[6]uril (CyP6Q[6]) and 2-(β-pyridine)-1H-imidazole [4, 5-f] [1, 10] phenanthroline hydrochloride(Ar-IPHS) was studied, and a fluorescent probe Ar-IPHS@CyP6Q[6] was prepared to identify amino acids by utilizing the property that CyP6Q[6] can make Ar-IPHS produce strong fluorescence. The experimental results showed that the probe can efficiently identify glycine, lysine, and methionine with detection limit of 2.27×10-6 mol/L, 1.359×10-5 mol/L, and 1.690×10-5 mol/L, respectively.
In this paper, the host-guest interaction of cyclopentyl substituted cucurbit[6]uril (CyP6Q[6]) and 2-(β-pyridine)-1H-imidazole [4, 5-f] [1, 10] phenanthroline hydrochloride(Ar-IPHS) was studied, and a fluorescent probe Ar-IPHS@CyP6Q[6] was prepared to identify amino acids by utilizing the property that CyP6Q[6] can make Ar-IPHS produce strong fluorescence. The experimental results showed that the probe can efficiently identify glycine, lysine, and methionine with detection limit of 2.27×10-6 mol/L, 1.359×10-5 mol/L, and 1.690×10-5 mol/L, respectively.
2020, 83(9): 821-827
Abstract:
[1+1] Schiff base macrocycle L1 was synthesized from the reaction of precursors N, N'-bis(3-aminophenyl)-pyridine-2, 6-dicarboxamide (1) with 5, 5'-methylene-bis-salicylaldehyde (2), and furthermore the macrocycle L1 was reduced to the corresponding saturated macrocycle L2. The two macrocycles were characterized by1H NMR, FABMS spectroscopies and elemental analysis, and their crystal structures were determined by X-ray diffraction analysis. The two macrocycles exhibited non-planar structures, and L2 showed a more flexible twisted conformation. The complexation of macrocycles with a series of anions was investigated by UV-Vis spectrometric titration technology. The results showed that L1 had obvious selective recognition ability for tetrahedral anions H2PO4-, HP2O73-, and H2P2O72-, respectively. Properties of the [1+1] Schiff base macrocycle L1 hydrogen-bonding interactions with these tetrahedral anions were investigated using UV-Vis and1H NMR titration, respectively. The stoichiometric ratio and binding constant (K) of the interaction were obtained. The results demonstrated that L1 binded the three anions with a 1:1 binding stoichiometry, and the bonding constants (Ka) increased in the order of H2PO4-, HP2O73-, H2P2O72-.
[1+1] Schiff base macrocycle L1 was synthesized from the reaction of precursors N, N'-bis(3-aminophenyl)-pyridine-2, 6-dicarboxamide (1) with 5, 5'-methylene-bis-salicylaldehyde (2), and furthermore the macrocycle L1 was reduced to the corresponding saturated macrocycle L2. The two macrocycles were characterized by1H NMR, FABMS spectroscopies and elemental analysis, and their crystal structures were determined by X-ray diffraction analysis. The two macrocycles exhibited non-planar structures, and L2 showed a more flexible twisted conformation. The complexation of macrocycles with a series of anions was investigated by UV-Vis spectrometric titration technology. The results showed that L1 had obvious selective recognition ability for tetrahedral anions H2PO4-, HP2O73-, and H2P2O72-, respectively. Properties of the [1+1] Schiff base macrocycle L1 hydrogen-bonding interactions with these tetrahedral anions were investigated using UV-Vis and1H NMR titration, respectively. The stoichiometric ratio and binding constant (K) of the interaction were obtained. The results demonstrated that L1 binded the three anions with a 1:1 binding stoichiometry, and the bonding constants (Ka) increased in the order of H2PO4-, HP2O73-, H2P2O72-.
2020, 83(9): 837-843
Abstract:
The photo-splitting mechanism of water to obtain H2 by Keggin-type polyoxometalate (POM) [SiW12O40]4- has been investigated using DFT and TD-DFT calculations. The catalytic cycle can be divided into four steps, i.e. (1) photoexcitation, (2) electron transfer and formation of one-electron-reduced (OER) intermediate, (3) formation of two-electron-reduced (TER) intermediate, and (4) H2 release and regeneration of the catalyst. Once an electron is transferred from CH3OH to POM, the following steps are thermodynamically favorable and induce the second electron transfer from ·CH2OH, H[SiW12O40]4-, or [SiW12O40]5- to OER intermediate H[SiW12O40]4- or [SiW12O40]5- to form TER intermediate [SiW12O40]6-, H[SiW12O40]5-, or H2[SiW12O40]4-, and accompanied by the generation of H2. Coupled proton and electron transfer pathway is energetic favorable. The participation of CH3OH and H2O is favorable to form H2. The POM acts as photosensitizer, catalyst, electron reservoir and donner in the entire catalytic cycle.
The photo-splitting mechanism of water to obtain H2 by Keggin-type polyoxometalate (POM) [SiW12O40]4- has been investigated using DFT and TD-DFT calculations. The catalytic cycle can be divided into four steps, i.e. (1) photoexcitation, (2) electron transfer and formation of one-electron-reduced (OER) intermediate, (3) formation of two-electron-reduced (TER) intermediate, and (4) H2 release and regeneration of the catalyst. Once an electron is transferred from CH3OH to POM, the following steps are thermodynamically favorable and induce the second electron transfer from ·CH2OH, H[SiW12O40]4-, or [SiW12O40]5- to OER intermediate H[SiW12O40]4- or [SiW12O40]5- to form TER intermediate [SiW12O40]6-, H[SiW12O40]5-, or H2[SiW12O40]4-, and accompanied by the generation of H2. Coupled proton and electron transfer pathway is energetic favorable. The participation of CH3OH and H2O is favorable to form H2. The POM acts as photosensitizer, catalyst, electron reservoir and donner in the entire catalytic cycle.
2020, 83(9): 828-836
Abstract:
In the present work, a series of novel 3-aroxymethylquinoxaline-2-carboxylic acids (4a~4l) were synthesized by a simple and facile method using the newly-synthesized ethyl 3-bromomethylquinoxaline-2-carboxylate (6) as substrate through one-pot sequential Williamson reaction with various phenols (8a~8l) followed by ester hydrolysis reaction. A preliminary screening for their in vitro antibacterial activities against five bacterial strains revealed that compounds 4j, 4k and 4l with tert-butyl and halo (F, Cl and Br) substituents exhibited significant activity against Gram (+) bacterials B. subtilis and S. aureus, among them 4j possessed the best activity with the MIC values of 15.625 and 7.8125 μg/mL, respectively, better than the reference drug Ciprofoxacin.
In the present work, a series of novel 3-aroxymethylquinoxaline-2-carboxylic acids (4a~4l) were synthesized by a simple and facile method using the newly-synthesized ethyl 3-bromomethylquinoxaline-2-carboxylate (6) as substrate through one-pot sequential Williamson reaction with various phenols (8a~8l) followed by ester hydrolysis reaction. A preliminary screening for their in vitro antibacterial activities against five bacterial strains revealed that compounds 4j, 4k and 4l with tert-butyl and halo (F, Cl and Br) substituents exhibited significant activity against Gram (+) bacterials B. subtilis and S. aureus, among them 4j possessed the best activity with the MIC values of 15.625 and 7.8125 μg/mL, respectively, better than the reference drug Ciprofoxacin.
2020, 83(9): 844-849
Abstract:
To achieve the goal of cultivating outstanding student who can promote the development of "New Agricultural Sciences" in agricultural universities, a comprehensive research experimental project was established. Through this comprehensive designing experiment project, students can acquire the technical ability of environmental material synthesis, component and structure characterization, property analysis, environmental pollution assessment, and so on, which involved in courses related to chemistry, materials and environment.In addition, this project also cultivates students' innovation consciousness, scientific research and team cooperation ability, and stimulates their environmental protection consciousness and social responsibility.
To achieve the goal of cultivating outstanding student who can promote the development of "New Agricultural Sciences" in agricultural universities, a comprehensive research experimental project was established. Through this comprehensive designing experiment project, students can acquire the technical ability of environmental material synthesis, component and structure characterization, property analysis, environmental pollution assessment, and so on, which involved in courses related to chemistry, materials and environment.In addition, this project also cultivates students' innovation consciousness, scientific research and team cooperation ability, and stimulates their environmental protection consciousness and social responsibility.
2020, 83(9): 850-855
Abstract:
According to the research on the development history of dry water, in the mid-20th century, scientists developed a kind of dry powder which was coated with water drops by silica particles and named it "dry water", but it did not attract people's attention for a long time. Until the beginning of the 21st century, a series of studies on the formation mechanism and preparation technology of dry water have been carried out successively. Subsequently, the huge potential application value of dry water attracted much attention, and its application in many fields such as cosmetics, hydrate gas storage, catalysts, and fire extinguishing agents was developed to a certain extent. The development of techniques related to dry water will lead to continuous innovation in the use of chemicals. The knowledge and history of dry water has changed people's understanding of water and will be an important part of chemistry textbooks and encyclopedias.
According to the research on the development history of dry water, in the mid-20th century, scientists developed a kind of dry powder which was coated with water drops by silica particles and named it "dry water", but it did not attract people's attention for a long time. Until the beginning of the 21st century, a series of studies on the formation mechanism and preparation technology of dry water have been carried out successively. Subsequently, the huge potential application value of dry water attracted much attention, and its application in many fields such as cosmetics, hydrate gas storage, catalysts, and fire extinguishing agents was developed to a certain extent. The development of techniques related to dry water will lead to continuous innovation in the use of chemicals. The knowledge and history of dry water has changed people's understanding of water and will be an important part of chemistry textbooks and encyclopedias.
2020, 83(9): 856-863
Abstract:
Zhang Zeyao is a modern Chinese chemical engineer. In the early 20th centrary, he returned to China after studying in the United States and committed himself to China's chemical engineering education and national industrialization. He made significant contributions to the development of the department of chemical engineering in National Peking University, Beijing Women's Normal University, Private Jiangnan University, and East China University of Science and Technology. His efforts to popularize chemical engineering to the society promoted the foundation and development of the Chinese Ceramic Society. This article is written to honor him on the 50th anniversary of his death. A review of his life can reflect the development of China's chemical engineering education in modern history.
Zhang Zeyao is a modern Chinese chemical engineer. In the early 20th centrary, he returned to China after studying in the United States and committed himself to China's chemical engineering education and national industrialization. He made significant contributions to the development of the department of chemical engineering in National Peking University, Beijing Women's Normal University, Private Jiangnan University, and East China University of Science and Technology. His efforts to popularize chemical engineering to the society promoted the foundation and development of the Chinese Ceramic Society. This article is written to honor him on the 50th anniversary of his death. A review of his life can reflect the development of China's chemical engineering education in modern history.
