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Progress in Chemistry 2002, No.06 Previous issue Next issue

In this issue:

Review
Recent Progress in Supercritical Water Theoretical Research
Chen Jinyang,Zheng Haifei,Zeng Yishan**
2002, 14 (06): 409- |
Published: 24 November 2002
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Abstract
Simulative computation, Raman spectroscopy, NMR and diffraction are the important methods to study the static structures of supercritical water. The results show that the hydrogen bond of supercritical water near critical region is only 29% of that of ambient condition. Microwave spectrum, NMR and quasielastic incoherent neutron scattering methods are adopted to study the dynamics of supercritical water. The results indicate that the time of rearrangement decreases greatly near critical region, which account for the increase of reaction rate in supercritical water. This is the basis for study of the mechanism of reaction rate in supercritical water. The microwave spectrum method is not appropriate for supercritical water at high temperature and low density conditons because the period of microwave is longer than the period of rearrangement. The experimental and simulative studies of mechanism and dynamics of hydrogen bond in supercritical water are the main research areas in the near future.
Progress on Sample Preparation Techniques for Analysis of Pesticide Residues in Foodstuffs
Yi Jun,Li Yunchun,Gong Zhenbin**
2002, 14 (06): 415- |
Published: 24 November 2002
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Abstract
The progress on sample preparation techniques for analysis of the pesticide residues in foodstuffs was reviewed. The applications of the supercritical fluid extraction (SFE), solid-phase microextraction (SPME), microwave aided extraction (MAE) and gel permeation chromatography (GPC) in analysis of pesticide residues in foodstuffs were described. Special attention was given to SFE technique and its hyphenation with gas chromatography (GO, high-performance liquid chromatography (HPLC) and gas chromatography-mass spectrometry (GC-MS). The trends of sample preparation techniques for analysis of pesticide residues in foodstuffs were also discussed.
Studies in Electrochemistry of Redox Proteins
Liu Huihong1,2,Pang Daiwen1**
2002, 14 (06): 425- |
Published: 24 November 2002
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Abstract
The Study of the electron-transfer process between the redox proteins and electrodes is not only valuabe in providing information to understand the metabolic process, but also is the basis of the preparation of biosensors. Recent advances in electrochemistry of redox proteins or enzymes are reviewed, including the design of protein-electrode interfaces, directional immobilization of proteins on electrodes and protein reconstruction, modification or engineering for electrochemistry. Further research areas are suggested.
Selective Redox Carbonylation to Ureas*
Mei Jianting1,2,Lu Shiwei1**
2002, 14 (06): 433- |
Published: 24 November 2002
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Abstract
A new process for the synthesis of ureas based on the selective redox carbonylation of amine and nitro compounds was described. The mechanism of carbonylation, the catalyst systems, the reaction selectivity were comprehensively reviewed. The synthesis of symmetric ureas?unsymmetric ureas and cyclic ureas by palliadium-catalyzed or selenium-catalyzed were emphasized. The perspective in their applications was also discussed.
Application of Axially Chiral Phosphinamine Ligands in Asymmetric Catalysis
Gao Shuang,Hu Xinquan,Zheng Zhuo*
2002, 14 (06): 438- |
Published: 24 November 2002
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Abstract
The progress in synthesis of chiral phosphinamine ligands is reviewed. Their applications in asymmetric allylic substitution, asymmetric 1, 4-conjugate addition and asymmetric hydroboration are described.
The Advances in Application of Chiral Binaphthol Phosphonite (Phosphite, Phosphoramidite)
Zhang Zhanjin1,2,Wan Boshun1,Chen Huilin1
2002, 14 (06): 446- |
Published: 24 November 2002
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Abstract
The advances in application of chiral 2, 2'-binaphthol phosphonite (phosphite, phosphoramidite) in the asymmetric catalysis has been reviewed.
Applications of Low Temperature Plasma in Catalysis*
Yu Kailu,Liu Changjun**,Xia Qing,Zou Jijun,Balder Eliasson
2002, 14 (06): 456- |
Published: 24 November 2002
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Abstract
Low temperature plasma has been extensively investigated for catalyst preparation, including plasma chemical synthesis of ultra-fine particle catalysts, plasma regeneration or plasma treatment of catalysts, plasma-assisted deposition of catalytically active compounds on carriers and combination of plasma and catalyst in reaction system. The plasma-prepared catalysts or catalysts modified by plasma exhibit higher catalytic reactivity. Combined with catalyst, plasma could be generated easily at lower voltage,which decreases the energy consumption and promotes the reactions.
Aliphatic Polycarbonates Synthesized with Carbon Dioxide
Wang Dongxian*,Kang Maoqing,Wan Xinkui
2002, 14 (06): 462- |
Published: 24 November 2002
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Abstract
The synthetic process and the catalytic systems used for the synthesis of aliphatic polycarbonates (APC) from carbon dioxide,as well as the physicochemical properties of APC and their modifications were reviewed. The properties of these copolymers and their applications are also described.
Progress in Study of Metallodendrimer
Hou Zhaosheng,Zhang Qizhen**,Li Guiying,Zhu Minggang
2002, 14 (06): 469- |
Published: 24 November 2002
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Abstract
This paper describes a class of metal-containing highly branched dendrimers - metallodendrimers. The noteworthy developments, the preparation, properties and potential applications of metallodendrimers are reviewed. The perspectives in their applications and studies are discussed.
Combinatorial Synthesis of Oligosaccharides
Chen Xiaofeng,Lu Zuhong*
2002, 14 (06): 477- |
Published: 24 November 2002
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Abstract
Saccharides have many key biological functions and the study of the structure-functions is of current interest. However, conventional method for oligosaccharides synthesis is very complicated and the manipulation is laborious and time consuming. With the development of combinatorial chemistry in synthesis of oligosaccharides, the possibility of constructing libraries of oligosaccharides is now appearing to be feasible. This article reviews progress in combinatorial synthesis of oligosaccharides.
The Development of Synthesis and Property of Polyferrocenophane with High Molecular Weight Prepared by Ring-opening Polymerization (ROP)
Wang Xuejie,Wang Li**
2002, 14 (06): 486- |
Published: 24 November 2002
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Abstract
In this paper, the recent development of the studies on high molecular weight polyferrocenophanes was reviewed. The methods and mechanisms of thermal, anionic, transition metal catalyzed ring-opening polymerization(ROP), as well as the structure, property and potential applications of resultant polyferrocenophanes have been described.