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Progress in Chemistry 2008, No.04 Previous issue Next issue

In this issue:

Review
High-throughput Natural Product Chemistry Methods and the Application of the Capillary NMR Probe

Hu Jinfeng1,2**|Gary R.Eldridge1,Yu Yihua3,Mark O's Neil-Johnson2

2008, 20 (04): 429-440 |
Published: 24 April 2008
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Abstract
High-throughput natural product chemistry methods, mainly consisting of two parallel multi-channel systems of preparative HPLC and LC-ELSD-MS, have been applied to the generation and analysis of large natural product libraries. The enhancement on mass sensitivity by the low volume capillary NMR probe (CapNMRTM) technology makes the NMR data acquisition, structure elucidation and de-replication on microgram amounts of natural products a reality. This state-of-the-art probe has ushered in a new era in the miniaturization of structure elucidation of natural products using mass-limited material. The perspectives for natural products as small molecular probes in brain functional genomics are briefly provided.
CO2/Ionic Liquids Phase Behaviors and Its Applications for Reaction and Separation
Wang Weibin|Yin Jianzhong*
2008, 20 (04): 441-449 |
Published: 24 April 2008
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Abstract
It is known that supercritical fluids (SCFs), room-temperature ionic liquids (ILs), CO2 expanded liquids (CXLs), water, as well as their mixtures are currently regarded as green solvents. Among them, the mixtures of SCFs and ILs have received considerable research attention due to their favorable thermodynamic properties. This review summarizes the recent progress in this filed, focusing on the factors that influence the phase behavior of SCFs and ILs, such as pressure, temperature, water contents, molar volume of ILs, co-solvents, anions, and cations. In addition, the phase behavior of the multicomponents containing the coupling solvent ILs/SCCO2 and the solute was also analyzed. Finally, the potential applications of ILs/SCCO2 coupling solvent are proposed, including extraction, anti-extraction, membrane separation, reverse micelle, and separation coupling with reaction. In particular, coupling separation with reaction using SCCO2/ILs as the green solvent will be one of the ways of clean production.
Hydrophobic Surface and Application to Drag Reduction
Jiang Xiong|Qiao Shengru**|Zhang Chengyu|Hu Haibao|Liu Xiaoju
2008, 20 (04): 450-456 |
Published: 24 April 2008
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Abstract
In this paper , the principles of hydrophobic surface and drag reduction are outlined .We briefly review the new way and recent progress to prepare such hydrophobic surface. The latest advance of hydrophobic surface research on drag reduction and weakness of such surface is mentioned here. The paper pants that anti-drag hydrophobic surface with the properties of hydrophobic 、wearable、corrosion resistant and good bonding strength can be prepared by adopting vapor deposition combined with in situ reactive infiltration , etc .
Hydroisomerization of n-Alkane
Liang Jun|Wang Fuping*
2008, 20 (04): 457-463 |
Published: 24 April 2008
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Abstract
The mechanisms of n-alkane hydroisomerization on bifunctional catalyst are reviewed including carbonium ion isomerization and cracking, pore and key-lock catalysis, shape selectivity, and bimolecular reaction. The effects of the charateristics such as acid intensity and strength, metal dispersion, the ratio of metal and acid cites, pore dimension and size, crystal particle size on the acitivity, selectivity of the catalyst are systematically discussed. The recent improvement methods of hydroisomerizaion catalyst are described. The methods of developing the activity and selectivity simultaneously are mentioned for respective kinds of catalyst.
Polymer-Laponite Nanocomposite Hydrogels with Super-Elongation
Xiong Lijun|Hu Xiaobo|Liu Xinxing|Tong Zhen**
2008, 20 (04): 464-468 |
Published: 24 April 2008
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Abstract
A novel nanocomposite hydrogel was prepared by in-situ radical polymerization of acrylamide monomers in the suspension of Laponite clay without cross-linkers. Laponite particle is a lamellar disk with diameter of 25-30 nm and thickness of 1 nm, which is believed to take the role of cross-linker in the hydrogel. This kind of hydrogel becomes the focus of smart materials with high transparency and excellent mechanical properties, which can be elongated up to 1 300%. Up to now, only acrylamide derivatives can be used in this polymerization. In this paper, we reviewed the recent research on the monomer, Laponite used in the gel and synthesis, structure, physical properties of the nanocomposite hydrogels with the structure and properties of Laponite. The possible development of this nanocomposite hydrogel in the near future is also discussed.
Liquid Phase Oxidation Reactions Catalyzed by Polyoxometalates
Lang Xianjun1,2 Lu Ruiling1,2 Li Zhen1 Xia Chungu1**
2008, 20 (04): 469-482 |
Published: 24 April 2008
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Abstract
After a brief introduction to the structure and general properties of polyoxometalates, the unusual versatility and tunability and their compatibility with environmentally and economically attractive conditions (solvents, oxidants, etc.) are outlined. These characteristics enable polyoxometalates suitable for catalyst to design at the atomic/molecular levels and applicable in the aspects of green catalysis and clean production. Recent developments of clean oxidation systems catalyzed by polyoxometalates are summarized in detail. The emphasis is on the epoxidation reaction of olefinic compounds, oxidation of alkanes and aromatic compounds with the comparatively ideal oxidants, hydrogen peroxide and molecular oxygen respectively. The oxidation mechanisms are elucidated in detail. In addition, the applications of polyoxometalate in the area of biomimetic catalysis are discussed.
Progress of Copper Electrocrystallization
Li Qiang1 Gu Min1** Xian Xiaohong2
2008, 20 (04): 483-490 |
Published: 24 April 2008
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Abstract
Copper electrodeposition has been widely applied in various industries because it has many advantages over other technologies and copper deposits has tremendous conductivity and good mechanical capability. Copper electrocrystallization process is the initial stage of copper electrodeposition. Copper electrocrystallization has always been attracted intensively because it determines not only the latter process of electrodeposition but also the structure and performance of the copper deposit obtained. In this paper, the developments of the study methods and the related theories for electrocrystallization are reviewed. The influence of pH, additives, foreign metal irons, substrate and the electrodeposition conditions on the electrocrystallization of copper are discussed in detail. The development trend in this field is also prospected.
Application on the Photonic Band Gap of Titanium Dioxide Photonic Crystals
Li Xiaojing1|Qiao Guanjun1*|Chen Jierong2|Zhou Xi1
2008, 20 (04): 491-498 |
Published: 24 April 2008
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Abstract
Recently the progress has been made in the area of controlling and manipulating photon with photonic crystal of titanium dioxide. In this paper photonic crystal of titanium dioxide, including sort, properties, fabrication, and application, are comprehensively reviewed. Photonic crystal of titanium dioxide is the promising material for its application in reflector, photoelectric conversion, chemical sensor and photocatalysis. At present, the synthesis of photonic crystal of titanium dioxide working at near infrared and visible wavelength is a hard work. Research field of photonic crystal of titanium dioxide in the future is dealt with in this review.
Advances in Fluorinated Liquid Crystals
Meng Fanbao|Lian Jiao|Gao Yongmei
2008, 20 (04): 499-507 |
Published: 24 April 2008
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Abstract
The progress in study of the fluorinated liquid crystals is reviewed. Based on the different positions of fluorine atoms or fluorinated groups on low molecular mass liquid crystals, they are classified in three species: liquid crystals bearing fluorine atom or fluorinated groups as terminal groups, liquid crystals containing benzene ring substituted hydrogen atoms by fluorine atoms, and liquid crystals with central bridge bond substituted hydrogen atoms by fluorine atoms. The effects of fluorine atoms and fluorinated groups on physical properties of liquid crystals are discussed according to characteristics of low molecular mass liquid crystals. The progress of fluorinated liquid crystalline polymers is also reviewed in brief.
Chiral Fluorescent Sensors-Based on Optically Active 1,1'-Bi-2-naphthyl Derivatives
Huang Hui|Zheng Lifei|Zou Xiaowei|Cheng Yixiang**
2008, 20 (04): 508-517 |
Published: 24 April 2008
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Abstract
Chiral BINOL and its derivatives are one of the most important C2 symmetric compounds. The chiral fluorescent sensors based on optically active 1,1’-bi-2-naphthol and its derivatives can be designed by strategic placement of substituents within the framework of a given BINOL derivative at the well-defined molecular level and used as excellent fluorescent chemosensors to chiral amines, amino alcohols, amino acids, α-hydroxycarboxylic acids chiral alcohols and monosaccharides due to their unique chiral configuration and fluorescent property. In this paper, the recent research progress of optically active 1,1’-bi-2-naphthol and its derivatives as fluorescence chemosensors for chiral molecular recognition is summarized.
Asymmetric Synthesis of Chroman Derivatives with Bioactivity
Wang Guixia1 Wang Naixing1** Tang Shi1 Yu Jinlan2 Tang Xinliang2
2008, 20 (04): 518-525 |
Published: 24 April 2008
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Abstract
Chroman derivatives are widely distributed in nature. Most chiral chroman derivatives have attracted great interest because of their important biological activities and their applications as intermediates for the synthesis of many important heterocyclic compounds. The key step of the synthesis of chroman derivatives is to construct chiral chroman ring. This review briefly summarizes the recent progress in the methodologies for the synthesis of chiral chroman derivatives. The applications of these methods in stereoselectively constructing chroman ring are discussed in detail.
High Nitrogen Compounds and Their Energy Materials
Yang Shiqing1 Xu Songlin1** Huang Hengjian2 Zhang Wei1 Zhang Xinggao1
2008, 20 (04): 526-537 |
Published: 24 April 2008
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Abstract
The development of energy materials based on high nitrogen energy compounds (HiNC) is one of the forefronts and hot areas of the energy materials, on account of their excellent or particular physics and chemsitry perfromance and explosive capability. The advances in the new high nitrogen compounds and energy materials are briefly reviewed. Relevant works of other groups worldwide are introduced, espically as the synthesis, performance and application investigation of tetrazine, tetrazole and furazan based HiNC. The application prospects of HiNC in insensitive high energy explosives, propellants and new gas generants is further explored according to author’s research.
Single Component White Light Electroluminescent Materials and Devices
Jiang Hongji|Huang Wei**
2008, 20 (04): 538-547 |
Published: 24 April 2008
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Abstract
On account of the advantages of organic electroluminescent materials relative to their inorganic counterparts, the development of organic electroluminescent materials is one of the forefronts and hot areas of the optoelectronic information materials. White organic light-emitting devices (WOLEDs) have attracted much interest because of their good potential for various lighting applications. An ideal white emission should be composed of the three primary colors (blue, green, and red) and cover the whole visible range from 400 to 700 nm. Most of the WOLEDs reported so far have relied on the use of a combination of several organic components that emit different colors of light to fully span the entire visible spectrum. Due to their advantages of ease of fabrication and low-cost processing, the single component white light electroluminescent materials is to date highly sought after owing to potential applications in (i) light-emitting diodes (LEDs), replacements for current illumination devices such as incandescent bulbs and fluorescent lamps, (ii) flat panel displays (FPDs), as the next generation display devices after liquid crystal displays (LCDs), and (iii) electronic paper displays (E-PADs), as an electronic analogue of paper, etc. The present review summarizes and analyzes the progress made about the single component white light electroluminescent materials and devices at home and abroad in the past few years. Some issues to be addressed and hotspots to be further investigated are also put forward to and discussed.
Aggregation Behavior of Amphiphilic C60 Derivatives in Aqueous Solution
Zhang Pu1** Lv Shuang2 Guo Zhixin1
2008, 20 (04): 548-557 |
Published: 24 April 2008
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Abstract
Poor solubility of C60 in water is among the main obstacles which hinder the potential utilization of fullerene-containing materials. Amphiphilic C60derivatives, which are relatively soluble in water, self-assemble into aggregates in water, have drawn great attention due to their special structures and properties. In this review, progress of the study on aggregation behavior of amphiphilic C60 derivatives in aqueous solution is described in detail. In the first part, we describe the structural morphology of the highly soluble amphiphilic C60 derivatives, particularly summarize these C60 derivatives according to the side groups attached to fullerene core. In the second part, we mainly discuss the aggregation of amphiphilic C60 derivatives in aqueous solution and the facts that can regulate the aggregation process, such as pH, solvent polarities, concentration, temperature and counter anion.
Full-Conjugated Ferrocene-Based Polymers
Shi Jianbing1|Zhi Junge2|Tong Bin1|Zhao Wei1|Shen Jinbo1|Dong Yuping1**
2008, 20 (04): 558-564 |
Published: 24 April 2008
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Abstract

This review focuses on the synthesis and properties of the special classe of full-conjugated ferrocenyl polymers with excellent properties, such as electrochemistry, redox, magnetism, catalysis, thermal-stability and so on. Due to their specialities of π-π electron structure, the full-conjugated ferrocenyl polymers have extensive applications in in optical, electronic and magnetic fields. The three types of polymers are described: full-conjugated main-chain ferrocenyl polymer, full-conjugated side-chain ferrocenyl polymer and full-conjugated hyperbranched ferrocenyl polymer. The influences of the polymer structures on solubility and redox behavior are discussed. Problems and possible prospects are also discussed.

Structural and Functional Study of Soybean Protein Isolation
Tian Kun|Guan Juan|Shao Zhengzhong|Chen Xin**
2008, 20 (04): 565-573 |
Published: 24 April 2008
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Abstract
Soybean protein isolation (SPI), the main component in soybean, may become an important chemical resource for the preparation of environmentally friendly materials because it contains many reactive groups and has the merits of being renewable and biodegradable. As the composition and conformation of SPI may significantly influence its appropriate functional properties, the systematic elucidation of the relationship between the structures and properties of SPI could help scientists to develop the novel soybean protein materials with excellent properties in the future. Thus in the beginning of this article, the composition, the subunit structures of SPI and the separation of its major components, beta-conglycinin (7S protein) and glycinin (11S protein) are introduced. Then, the conformation studies under different conditions and the main physical-chemical properties of SPI, such as solubility and gelation property are summarized. At last, the applications of SPI as films, fibers and plastics in the material field are briefly reviewed.
Water-Soluble Conjugated Polyelectrolytes
Huang Yanqin|Fan Quli|Huang Wei**
2008, 20 (04): 574-585 |
Published: 24 April 2008
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Abstract
Water-soluble conjugated polyelectrolytes (WSCPs) are novel types of conjugated polymers which contain ionic side chains, hence they are soluble in water and some other polar organic solvents. These polymers combine the optoelectronic advantages of traditional conjugated polymers with water solubility and ionic nature of polyelectrolytes. This research field is becoming more and more attractive due to their unique optoelectronic properties that may serve as the basis for a new generation of optoelectronic devices and bio/chemical sensors. In this paper, we summarize the synthetic methods, structure features and photophysical properties of WSCPs developed in recent ten years, and their applications in a new generation of optoelectronic devices and bio-chemical detection. On this basis, we point out the existent problems in the present research and applications of WSCPs，and also give a perspective on their future.
Photoelectrochemical Semiconductor Biosensors
Peng Fang1|Zhu Derong2|Si Shihui1**|Xiao Hui1
2008, 20 (04): 586-593 |
Published: 24 April 2008
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Abstract
Photoelectrochemical semiconductor biosensor is a new kind of analytical technology for the detection of the concentration of analytes and the parameters of biochemical processes in relation to photocurrent or photopotential. Photoelectrochemical semiconductor bioseneors have showed advantages in the aspects of micromation, intergration, multipoint and multiparameter measurement along with the appearance of new semiconductor functional materials and relative technologys.It is hopeful to achive high sensitivity and rapid detection online in the complicated systems and find the wide applications in the fields of biology, medicine, environment monitoring, foodstuff and so on. The basic principle, characteristics and research progresses of photoelectrochemical semiconductor biosensors are discussed in detail and their future developments are also prospected.
Desorption Electrospray Ionization
Xue Zhen|Qiu Bo|Lin Guangxin|Lai Congfang|Luo Hai**
2008, 20 (04): 594-601 |
Published: 24 April 2008
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Abstract
Desorption electrospray ionization (DESI), a new ionization method of mass spectrometry, and its most recent research advances were reviewed. This method was first introduced in 2004 and developed very rapidly because of its advantageous analytical characteristics, such as ambient working conditions, without sample preparation, and capable of directly analyzing solid or condensed form of samples from a variety of substrate surfaces. The comprehensive recent studies of DESI are reviewed in several aspects, including its basic principle, ion source structure, the optimal operational parameters and the substrate surfaces used in the ionization process. This article also summarizes applications of DESI technique in monitoring ambient gas-phase chemical reaction products, characterizing synthetic polymers, detecting explosives and chemical warfare agents, analyzing drugs and metabolites, and profiling biological tissue surfaces. Meanwhile, the future directions of fundamental and applied research using DESI technique are commented.
Polymer Electrolyte Membranes for Fuel Cells
Zhang Hongwei|Zhou Zhentao
2008, 20 (04): 602-619 |
Published: 24 April 2008
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Abstract
This paper presents a brief review of the definition, classification, working principle and characteristic of polymer electrolyte membrane fuel cells and a more detailed review of the progress on polymer electrolyte membranes (PEM) in recent years. Recent developments in the field include acid anionic polymer electrolyte membrane (AAPEM)s such as perfluorosulfonic acid membranes, sulfonated aromatic polymer membranes, sulfonated polyimide membranes, aliphatic hydrocarbon polymer membranes, organic/organic or organic/inorganic composite membranes and alkaline cationic polymer electrolyte membranes (ACPEM). As well, a preliminary description is given of the relation between proton conductivities and methanol permeabilities of AAPEMs. Finally, the further advancements in the area of PEMs are also summarized.
Further Analysis on the Choking Criteria in the EMMS Model
Cheng Changjian1,2 Ge Wei1**
2008, 20 (04): 620-624 |
Published: 24 April 2008
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Abstract
Choking is a typical critical phenomenon in gas-solid fluidization featuring abrupt structural changes. The Energy Minimization Multi-Scale (EMMS) model is capable of analyzing the mechanism of this phenomenon. In this paper, two criteria for choking previously proposed on the basis of the EMMS model are discussed with the emphasis on the difference and consistency between them. Simulation result shows that the saturation carrying capacities calculated with the two criteria are approximately equivalent at given gas velocities. It is demonstrated further that the mechanism reflected by these two criteria is consistent. Both criteria have defined the critical condition for the regime transition between fast fluidization and dilute transport.