Table of Content

25 November 2011, Volume 27 Issue 6

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Cover and Content of Chemical Research in Chinese Universities Vol.27 No.6(2011)

2011, 27(6):  0. 

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Volume Contents of Chemical Research in Chinese Universities to Vol.27(2011)

2011, 27(6):  1. 

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Articles

Synthesis of Nitrogen Incorporated Carbon Nanotubes with Different Diameters by Catalytic Pyrolysis of Butylamine

JIN Hai-ying, BING Nai-ci, WANG Ling-ling and WANG Li-jun*

2011, 27(6):  903-905. 

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Bamboo-like nitrogen-doped carbon(CNx) nanotubes were synthesized by chemical vapor deposition (CVD) at a high reaction temperature of 600―900 °C. The butylamine and Fe/SBA-15 molecular sieve have been used as precursor and catalyst, respectively. Transmission electron microscopy(TEM) and high resolution transmission electron microscopy(HRTEM) observations show that the outer diameter and wall thickness as well as the inner diameter were increased with increasing reaction temperature in a temperature range of 600―800 °C. A synergism mechanism of the growth through bulk diffusion and the competitive growth through surface diffusion functions  during the synthesis of CNx nanotubes was proposed.



Dispersion of ZnO Nanocrytals in Co-solvent and Its Application in Photovoltaic Material

CHEN Shao-jie, ZHANG Qiu-yu*, ZHANG Jun-ping, GU Jun-wei, ZHOU Jian and SHI You-qiang

2011, 27(6):  906-909. 

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To overcome the aggregation of nanocrystals in a blend of inorganic material with conjugated polymers to prepare photovoltaic material, we used a co-solvent blend of CHCl3 with MeOH at a certain volume fraction to disperse inorganic nanocrystals. The results show that when the volume fraction of MeOH is 50%, ZnO nanocrystals with an average diameter of 30 nm disperse well in the co-solvent solution. Its application in photovoltaic material was investigated in this work, and the photoluminescence(PL) spectra show that when ZnO was 50%(volume fraction) in solution and 25%(volume fraction) in film, the fluorescence quenching reached the maximum values 83.34% and 64.4%, respectively, indicating that electron could transfer from conjugated polymer to electron-acceptor ZnO effectively.



Synthesis and Characterization of Layered Co2(OH)3(CH3COO)?H2O

ZHENG De-shan*, WANG Yan-zhong, SHI Li-min and SUN Si-xiu

2011, 27(6):  910-914. 

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Layered hydroxide metal acetate Co2(OH)3(CH3COO)?H2O with an interlayer spacing of 1.282 nm has been synthesized by a novel method which is employed in ethanol-aqueous mixed solvents media. Experiment results show that the purity of the product by the modified method is higher compared with that by the previous methods. A complete characterization of the as-prepared samples was performed by means of X-ray powder diffraction, IR spectroscopy, scanning electron microscope, as well as magnetic measurement. The facile and effective approach for the preparation of this compound in this study is very interesting and important because it has wide application in the field of anionic exchange reaction for the synthesis of hybrid organic-inorganic compounds.



Solvothermal Synthesis and Characterization of Sheet Structure Containing Adamantane [Hg2Sn2S10]8– Anions

BAIYIN Meng-he*, LIANG Feng-ying, XU Xiao-qing, TA Na, NA Mi-la, BAI Wu-yun and BAO Yong-sheng

2011, 27(6):  915-918. 

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Sheet Rb2HgSnS4 was synthesized solvothermally and characterized by X-ray single crystal diffraction. The compound is comprised of sheets with admantane-like [Hg2Sn2S10]8– units. The crystals belong to the space group C2/c, with the unit cell parameters a=1.1063(2) nm, b=1.1071(2) nm, c=1.5741(3) nm, a=90°, β=100.13(3)°, γ=90°. A reflectance spectroscopy study reveals the nature of the semiconductor with an energy of 2.1 eV for the compound.



Synthesis and Photoluminescence Properties of Uniform Y2O3:Eu3+ Hollow Spheres with Tunable Shell Thickness

XIAO Ying, GAO Zhi-yong, WU Da-peng, JIANG Yi, LIU Ning and JIANG Kai*

2011, 27(6):  919-923. 

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Y2O3:Eu3+ hollow spheres were successfully prepared with melamine formaldehyde(MF) spheres as template. The MF spheres played a significant role in directing the formation of the hollow shells which are composed of numerous primary nanoparticles. Furthermore, the shell thickness of these hollow spheres could be readily tailored by adjusting the dosage of MF template. Based on the photoluminescence(PL) investigation, the red emission intensities(613 nm) of these Y2O3:Eu3+ hollow spheres are greatly influenced by their shell thickness and it was found that hollow spheres with thin shell thickness and intact hollow structures permit a better PL performance.



Application of Grey-correlated Spectral Region Selection in Analysis of Near-infrared Spectra

2011, 27(6):  924-928. 

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The optimal selection method of spectral region based on the grey correlation analysis was applied in the analysis of near-infrared(NIR) spectra. In order to compute “characteristic” spectral region, 160 samples of tobacco were surveyed by NIR. Next, the whole spectral region was randomly divided into six regions, and the values of association coefficients and correlation orders of different regions were computed for total sugar, reducing sugar and nicotine. Moreover, two regions that owned the largest value of association coefficient were regarded as “characteristic” spectral region of a model. Finally, the quantitative analysis models of different components were established via the partial least squares method, and the common selection methods of spectral region were compared. The simulation results indicate that the models to choose the spectral region based on grey correlation analysis are more effective than the common selection methods of spectral region, the optimized time of algorithm is shorter, the prediction precision of the models is higher and generalization ability for quantitative analysis results is stronger. This research can provide the support for the quantitative analysis models of NIR spectra and new idea for commercial analysis software of NIR. So, it has a high application value in the analysis of NIR spectra.



Flow-injection Spectrophotometric Determination of Uric Acid in Urine via Prussian Blue Reaction

WASEEM Amir*, YAQOOB Mohammad, NABI Abdul, MURTAZA Ghulam and HUSSAIN Izhar

2011, 27(6):  929-933. 

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A simple and sensitive flow injection(FI) spectrophotometric method was reported for the determination of uric acid based on the reduction of Fe(III)/ferricyanide in the presence of uric acid. The in situ reduced ions reacted with unreduced portion of ferricyanide/Fe(III) to form soluble Prussian blue, which was monitored at an absorption wavelength of 735 nm. The optimized conditions allow a linear calibration graph in a concentration range of 1―100 μmol/L. The relative standard deviation was in a range of 0.5%―2.5%, with a detection limit(3σ blank) of 0.3 μmol/L and a sampling frequency of 60 injection/h was obtained. The effect of common substances present in human physiological fluids on the determination of uric acid was examined. The method was applied to determining uric acid in human urine samples with the recoveries in a range of 96%―105%. The results agree well with those by spectrophotometric reference method at a confidence level of 95%. Spectrophotometric procedures for uric acid determination in clinical samples were reviewed briefly.



Electrochemical Determination of Reduced Glutathione at Multiwalled Carbon Nanotubes/Poly(bromocresol green) Modified Glassy Carbon Electrode

HOU Ju-ying and AI Shi-yun*

2011, 27(6):  934-938. 

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A multiwalled carbon nanotubes/poly(bromocresol green) modfied glassy carbon electrode (MWNTs-PBG/GCE) was used to investigate the electrochemical behavior of reduced glutathione(GSH). GSH showed an irreversible oxidation process on MWNTs-PBG/GCE with an oxidation peak at 0.77 V(vs. SCE) in a phosphate buffer solution(pH=4.0). The kinetic parameters of the electrochemical behavior of GSH on MWNTs-PBG/GCE were calculated. Under the optimal conditions and with the help of amperometric method, a linear relationship was obtained between the oxidation peak current and GSH concentration in the range from 2×10–7 mol/L to 5×10–6 mol/L with the detection limit as 1×10–8 mol/L(signal-to-noise ratio of 3). The current reached the steady-state current within about 5 s. The modified electrode surface had very good reproducibility and stability.



Liquid-liquid Microextraction Based on Solidification of Floating Organic Drops Coupled with Gas Chromatography for Analyzing Trace Benzene, Toluene and Xylene in Water Samples

ZHANG Mao-sheng*, HUANG Jia-rong, ZHENG Xiang-hua and XIE Qiong-fang

2011, 27(6):  939-943. 

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A new liquid-liquid microextraction method based on the solidification of floating organic drops coupled with gas chromatography was developed for the determination of trace benzene, toluene and xylene(BTX) in water samples. In the microextraction procedure, a microdrop of n-decanol was delivered to the surface of the analytes’ solution, and stirred for a desired time. Following the absolute extraction, the sample vial was cooled in an ice bath for 10 min. The solidified n-decanol was then transferred into a plastic tube and melted naturally; and 1 μL of it was injected into gas chromatography for analysis. Factors relevant to the extraction efficiency were studied and optimized. The optimal experimental conditions were: 15 μL of n-decanol as extractive solvent, 30 mL of solution containing analytes, no salt, the stirring rate 400 r/min, the extraction temperature 30 °C, and the extraction time 30 min. Under those optimized conditions, the detection limit(LOD) of analytes was in a range of 0.05―0.10 ng/mL by the developed method. A good linearity(r>0.99) in a calibration range of 0.01―100 μg/mL was obtained. The recoveries of the real samples at different spiked levels of BTX were in the range from 92.2% to 103.4%.



Artificial Neural Network and Full Factorial Design Assisted AT-MRAM on Fe Oxides, Organic Materials, and Fe/Mn Oxides in Surficial Sediments

GAO Qian, WANG Zhi-zeng, WANG Qian, LI Shan-shan and LI Yu*

2011, 27(6):  944-948. 

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Artificial neural network(ANN) and full factorial design assisted atrazine(AT) multiple regression adsorption model(AT-MRAM) were developed to analyze the adsorption capability of the main components in the surficial sediments(SSs). Artificial neural network was used to build a model(the determination coefficient square r2 is 0.9977) to describe the process of atrazine adsorption onto SSs, and then to predict responses of the full factorial design. Based on the results of the full factorial design, the interactions of the main components in SSs on AT adsorption were investigated through the analysis of variance(ANOVA), F-test and t-test. The adsorption capability of the main components in SSs for AT was calculated via a multiple regression adsorption model(MRAM). The results show that the greatest contribution to the adsorption of AT on a molar basis was attributed to Fe/Mn(–1.993 μmol/mol). Organic materials(OMs) and Fe oxides in SSs are the important adsorption sites for AT, and the adsorption capabilities are 1.944 and 0.418 μmol/mol, respectively. The interaction among the non-residual components(Fe, Mn oxides and  OMs) in SSs interferes in the adsorption of AT that shouldn’t be neglected, revealing the significant contribution of the interaction among non-residual components to controlling the behavior of AT in aquatic environments.



Synthesis of Naturally Occurring Neolignans Demethylnitidanin, Herpetol and Salvinal as well as Their Glycosyl Derivatives

WU Zheng, LIANG Zhi-ying, LI Wei, REN Ying-mei and WANG Qiu-an*

2011, 27(6):  949-954. 

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Three neolignans, (±)-demethylnitidanin(1), herpetol(2) and salvinal(3) were synthesized from methyl 4,5-dihydroxy-3-methoxy cinnamate or methyl 4-hydroxy-3-methoxy cinnamate with Ag2O-catalyzed biomimetic oxidative coupling as the key step of the synthetic route. Five novel benzofuran neolignan-4'-O-β-D-glycosides(4―8) were achieved by the glycosylation reactions of benzofuran neolignans 2, 3 and 15. The structures of all the compounds synthesized were determined by MS, 1H NMR and IR spectra. (±)-Demethylnitidanin(1) and herpetol(2) were the first synthesized and the synthesis of salvinal(3) was efficiently improved by the new synthetic routes.



Design, Synthesis and Antifungal Activity of 6-fluoro-3,3a,4,5-tetrahydro-2H-pyrazolo[4,3-c]quinoline-2-carboxamide Derivatives

YUAN Jing, SU Xin, ZHANG Xin, CONG Lin and GUO Chun*

2011, 27(6):  955-957. 

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A series of 6-fluoro-3,3a,4,5-tetrahydro-2H-pyrazolo[4,3-c]quinoline-2-carboxamide derivatives was designed based on the bioisosterism and combination principle in drug design. The target compounds were synthesized from substituted aniline through Michael addition, cyclization, Mannich reaction and condensation with 4-substituted semicarbazides, and the structures were confirmed by mass spectrometry(MS) and 1H NMR. The antifungal assay was carried out in vitro by two-fold dilution. The result shows that all the compounds are of antifungal activities against the tested fungi at different levels.



Highly Stereoselective Synthesis of trans-3-Chloro-?-lactams from Imines and Mixed Chloroacetyl and Nitroacetyl Chlorides

QI Heng-zhen, MO Shan-yan and XU Jia-xi*

2011, 27(6):  958-962. 

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A series of trans-3-chloro-β-lactams was synthesized stereospecifically from imines and chloroacetyl chloride or a mixture of chloroacetyl chloride and nitroacetyl chloride, prepared from vinylidene chloride and a mixture of concentrated nitric acid and sulfuric acid, in the presence of triethylamine. The reaction of vinylidene chloride and the mixed acid was investigated. The formation mechanism of chloroacetyl chloride and nitroacetyl chloride and their reaction process with imines were proposed.



Synthesis, Crystal Structure and Theoretically Study of 2-(Dimethylamino)-1,3-dithiocyanatopropane and Its Isomer

YU Guan-ping, MA Yi, LIU Zhuo, WANG Gang and LI Zheng-ming*

2011, 27(6):  963-967. 

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2-(Dimethylamino)-1,3-dithiocyanatopropane(1) has been prepared as a key intermediate synthesizing a natural insecticide Cartap by the reaction of 1-dimethylamino-2,3-dichloropropane with sodium thiocyanate. The crystal structures of compound 1 and its isomer 1-(dimethylamino)-2,3-dithiocyanotopropane(2) formed during the reaction were determined by X-ray single-crystal diffraction. Bond lengths in both the compounds are common and fall within normal ranges. There are some weak C―H×××N hydrogen bonds in the lattice of compound 1, which makes it form a three-dimensional network, which stabilize the crystal structure. No classic hydrogen bonds were founded in its isomer(2), only van der Waals forces contribute to the stability of the structure. In addition, DFT and MP2 calculations with 6-311+G(d, p) basis set have also been carried out to investigate the thermodynamic properties of compounds 1 and 2. The research will be applied to the further investigation of the tautomerization of compounds 1 and 2.



Spirodiclofen Derivatives as Highly Potential Acaricides: Synthesis, Structure and Bioactivity

FENG Xian-guo, XU Liang-zhong*, KONG Fan-rui, LI Hong-xin and YIN Rui-feng

2011, 27(6):  968-972. 

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A series of new compounds as highly potential acaricides was synthesized based on the structure of spirodiclofen. Their structures were identified by 1H NMR spectroscopy and element analysis. The bioassay indicated that most of the compounds exhibited excellent acaricidal activities, what's more, the bioactivities of some new compounds were better than that of the commercial spirodiclofen at a concentration of 20 μg/mL. The relationship   between structure and biological activity was also discussed.



BrΦnsted Acidic Ionic Liquids: Efficient and Recyclable Catalytic Systems for Beckmann Rearrangement

WU Mao-cheng, DUAN Hai-feng*, CAO Jun-gang, LIANG Da-peng, JIANG Feng, GAO Han, JIA Xu-dong and LIN Ying-jie

2011, 27(6):  973-976. 

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Six BrΦnsted acidic ionic liquids(ILs) 1a―1f were synthesized and used as the dual solvent-catalyst systems for Beckmann rearrangement reactions. Among ILs 1a―1f, IL 1a exhibited the highest catalytic activity and successfully catalyzed the Beckmann rearrangement of ketoximes, and the corresponding amides were obtained in good to excellent yields(74%―92%). In addition, IL 1a could be recovered easily and reused at least three times without any loss of catalytic activity.



Synthesis of 2-Phenyl-10-substituted Hymenialdisine Derivatives

WU Yi, WANG Yu, QIN Yong and SONG Hao*

2011, 27(6):  977-980. 

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A series of novel 2-phenyl-10-substituted hymenialdisine derivatives was synthesized via the microwave-assisted Suzuki-Miyaura cross-coupling reactions of the 2-phenyl derivative of hymenialdisine and boronic acid, which enabled the successful introduction of electron-donating and electron-withdrawing groups to the 2-phenyl- hymenialdisine derivatives in good yields.



New Way to Synthesize DW286―a Novel Fluoronaphthyridone Antibacterial Agent

FENG Lian-shun, LIU Ming-liang*, ZHANG Yi-bin and GUO Hui-yuan

2011, 27(6):  981-983. 

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A new route for the synthesis of DW286, 7-[3-(aminomethyl)-4-(methoxyimino)-3-methyltetrahy- dro-1H-1-pyrrolyl]-1-cyclopropyl-6-fluoro-4-oxo-1,4-dihydro[1,8]naphthyridine-3-carboxylic acid hydrochloric acid salt, is described. In the presence of benzadehyde, DW286 was prepared by the direct condensation of 7-chloro-1-cyclopropyl-6-fluoro-4-oxo-1,4-dihydro[1,8]naphthyridine-3-carboxylic acid with new pyrrolidine derivative 7 which could be obtained by routine reactions.



Stereoselective Synthesis of Polysubstituted Cyclopropanes from Poly(ethylene glycol) Supported Pyridinium Ylide

ZHAO Pan, LU Cui-fen, YANG Gui-chun, CHEN Zu-xing*, DONG Nian-guo and SHI Jia-wei

2011, 27(6):  984-987. 

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Polysubstituted cyclopropanes were efficiently prepared with poly(ethylene glycol)(PEG) as soluble support. The reaction of PEG-supported pyridinium ylide with arylidenemalononitrile(R=CN) or ethyl arylidenecyanoacetate(R=COOEt) in the presence of triethylamine(TEA) afforded PEG-supported cyclopropanecarboxylates, which were cleaved by 1% KCN/EtOH to obtain polysubstituted cyclopropanes with exclusive trans-selectivity and good yields.



Serine659 in ClC-2—Target Site for Phosphorylation by MAPK

ZHAO Jing, ZHENG Ya-juan, LI Gui-rong, CHEN Jie, YU Qian* and XIN Hua*

2011, 27(6):  988-991. 

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In order to further investigate the role of ClC-2(ClC=chloride-ion channel) played in the regulation of cell proliferation and differentiation, the capablity of ClC-2 phosphorylation catalyzed by mitogen-activated protein kinase(MAPK) was studied. A mutation of 659Ser to Ala(S659A) of the rabbit ClC-2 cDNA in the consensus sequence of MAPK phosphorylation was introduced by overlap extension polymerase chain reaction(PCR). Recombinant vectors pGEX-4T-1/ClC-2-2CT and pGEX-4T-1/ClC-2CT(S659A) were constructed. They were transformed to E. coli BL21, expressed by isopropy-β-D-thiogalactoside(IPTG) induction, the recombinant proteins were subjected to purification by glutathione sepharose 4B affinity chromatography. In vitro phosphorylation of the fusion proteins catalyzed by MAPK was performed. The results show that fusion protein GST/ClC-2CT(wild type) can be phosphorylated by MAPK, and this phosphorylation can be restrained by the inhibitor p42/44MAPK, PD98095; while the phosphorylation level of fusion protein GST/ClC-2CT(S659A)(mutant) was significantly reduced. Therefore, ClC-2 can be phosphorylated by MAPK and the target site of the phosphorylation is most likely the 659Ser residue.



Enzymatic Synthesis of Agmatine by Immobilized Escherichia coli Cells with Arginine Decarboxylase Activity

ZHANG Wei-guo, ZHAO Gen-hai, LIU Jun-zhong, LIU Qian and JIAO Qing-cai*

2011, 27(6):  992-995. 

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A new method for the enzymatic synthesis of agmatine by immobilized Escherichia coli cells with arginine decarboxylase(ADC) activity was established and a series of optimal reaction conditions was set down. The arginine decarboxylase showed the maximum activity when the pyridoxal phosphate(PLP) concentration was 50 mmol/L, pH=7 and 45 °C. The arginine decarboxylase exhibited the maximum production efficiency when the substrate concentration was 100 mmol/L and the reaction time was 15 h. It was also observed that the appropriate concentration of Mg2+, especially at 0.5 mmol/L promoted the arginine decarboxylase activity; Mn2+ had little effect on the arginine decarboxylase activity. The inhibition of Cu2+ and Zn2+ to the arginine decarboxylase activity was significant. The immobilized cells were continuously used 6 times and the average conversion rate during the six-time usage was 55.6%. The immobilized cells exhibited favourable operational stability. After optimization, the maximally cumulative amount of agmatine could be up to 20 g/L. In addition, this method can also catalyze D,L-arginine to agmatine, leaving the pure optically D-arginine simultaneously. The method has a very important guiding significance to the enzymatic preparation of agmatine.



Denaturation Kinetics of N-Acetyl-β-D-glucosaminidase from Scylla serrata in Urea Solution

LIN Jian-cheng, LI Hua-liang, CHEN Liang-hua, YANG Xue-min, WANG qin and CHEN Qing-xi*

2011, 27(6):  996-999. 

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N-Acetyl-β-D-glucosaminidase(NAGase, EC 3.2.1.52), which catalyzes the cleavage of N-acetylgluco- samine polymers, plays important roles in the molting, digestion of chitinous foods in green crab. In the study, the efforts of urea on the activity of NAGase purified from the viscera of green crab(Scylla serrata) have been studied. The results show that appropriate concentrations of urea can lead to reversible inactivation of the enzyme, and the value of the inhibitor concentration leading to 50% of enzyme activity lost(IC50) is estimated to be 0.63 mol/L. The inactivation kinetics has been studied via the kinetic method of the substrate reaction. The rate constants of inactivation have been determined. The value of k+0 is larger than that of k′+0, indicating the free enzyme molecule is more fragile than the enzyme-substrate complex in urea solution. It is suggested that the presence of the substrate offers the marked protection of this enzyme against inactivation by urea.



Novel Type II Peroxiredoxin Gene Homologue from Chinese Wildrye Enhancing Salt Stress Tolerance of Transgenic Yeast

YU Ying, LIU Xiang-guo, LU Yang, DOU Yao, WANG Hu-yi, HAN Si-ping, FENG Shu-dan and HAO Dong-yun*

2011, 27(6):  1000-1005. 

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Peroxiredoxins(Prxs) are a large family of antioxidant enzymes of various types that take part in signal transduction via decomposing reactive oxygen species(ROS). Although extensive efforts have been made over the last decades in understanding the structures and functions of Prxs, type II Prxs in monocots are hardly studied. In this work, a monocot type II Prx gene homologue from Chinese wildrye(Leymus Chinensis), designated as LcTpxII, was isolated and characterized. LcTpxII encoding a 162-amino acid protein contains a thioredoxin domain and a cysteine residue at position 51, suggesting that it is a member of the Prxs family. The LcTpxII is capable of decomposing H2O2 and protecting plasmid DNA from damage caused by ROS. The expression of LcTpxII in Chinese wildrye was induced by 400 mmol/L NaCl and 100 mmol/L Na2CO3 in the experiment. The overexpression of LcTpxII enhances the tolerance of transgenic yeast to 1.6 mol/L NaCl and 10 mmol/L Na2CO3.



Hydroxylation Reaction Mechanism for Nitrosodimethylamine by Oxygen Atom

LI Lan*, LIN Xiao-yan and LI Zong-he

2011, 27(6):  1006-1009. 

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The hydroxylation reaction mechanism of nitrosodimethylamine(NDMA) by oxygen atom was theoretically investigated at the B3LYP/6-31G** level. It has been found that the path of the oxydation of the C―H bond is easier than the path involving a Singlet/Triplet crossing. The study of the potential surface shows that both solvent effect at B3LYP/6-31G** level and different method at more credible MP2/6-311G** level in the gas phase have no effect on the hydroxylation reaction mechanism. The oxidation hydroxylation process of NDMA by O is exothermic reaction and easy to occur.



Selective Synthesis of 2,6-Dimethylnaphthalene by Transalkylation in the Presence of Acid Ionic Liquids [Cnmim]Cl-AlCl3

WU Guang, WU Wei*, XIAO Lin-fei and LIU Dan

2011, 27(6):  1010-1013. 

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A highly selective synthesis of 2,6-dimethylnaphthanlene(2,6-DMN) by transalkylation between 2-methylnaphthanlene(2-MN) and 1,2,4,5-tetramethylbenzene(TeMB) was performed with 1-alkyl-3-methylimidazo- lium aluminum chloride([Cnmim]Cl-AlCl3) ionic liquids(ILs) as catalysts. The influences of the alkyl group as the organic cation, the acidic strength of [C4mim]Cl-AlCl3 ILs as well as the reaction conditions on the catalytic performance were investigated. [C4mim]Cl-AlCl3 ILs[x(AlCl3)=71%] exhibited high activity and selectivity toward 2,6-DMN. The selectivity to 2,6-DMN and the 2,6-DMN/2,7-DMN ratio reached up to 68.2% and 3.7:1, respectively. The UV-Vis spectrum of TeMB treated by different ILs shows that the protonated degree of TeMB dependeds on the acidity strength of ILs, which has a significant impact on the reaction results. The high protonated degree of TeMB is advantageous to enhancing the conversion of transalkylation and the large stereo-hindrance effect of TeMB is favorable to improving the selecivity to 2,6-DMN.



Highly Active New α-Diimine Nickel Catalyst for Polymerization of Ethylene

YUAN Jian-chao*, LIU Yu-feng, MEI Tong-jian and WANG Xue-hu

2011, 27(6):  1014-1018. 

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A new α-diimine ligand 1a, bis[N,N'-(4-tert-butyl-2,6-dimethylphenyl)imino]-2,3-butanediylidene and its corresponding Ni(II) complex 2a, {bis[N,N'-(4-tert-butyl-2,6-dimethylphenyl)imino]-2,3-butanediylidene}dibromo- nickel were successfully synthesized, and characterized by 1H NMR, 13C NMR, Fourier transform infrared spectroscope(FTIR), elemental analysis and X-ray photoelectron spectroscopy(XPS). α-Diimine ligand 1b, bis[N,N'-(2,6-  dimethylphenyl)imino]-2,3-butanediylidene and its corresponding Ni(II) complex 2b, {bis[N,N'-(2,6-dimethyl- phenyl)imino]-2,3-butanediylidene}dibromonickel were also synthesized and characterized for comparison. The pre-catalyst 2a with sterically bulky, electron-donating group tert-butyl, activated by diethylaluminum chloride (DEAC) and tested in the polymerization of ethylene, was very highly active[2.01×107 g PE/(mol Ni·h·0.1 MPa)] and led to a very highly branched polyethylene(ca. 35―103 branches/1000 C). The state of the polyethylene obtained varied from plastic, elastomer polymers to the oil-like hyperbranched polymers.



Liquidus Temperatures of System Na3AlF6-K3AlF6-AlF3 for Aluminum Electrolysis at Lower Temperature

WEI Chen-juan, LAI Yan-qing, LI Jie*, TIAN Zhong-liang, WANG Jia-wei, ZOU Zhong and LIU Ye-xiang

2011, 27(6):  1019-1022. 

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Liquidus temperatures in the molten salt system Na3AlF6-K3AlF6-AlF3 of interest for aluminum electrolysis were determined by thermal analysis method. The results were presented and an empirical equation describing  liquidus temperatures for primary crystallization was derived t=1003.5–0.081×A2.3159–5.87×B0.657–0.024×A2.22×B1.14+ 0.035×A2.17×B1.084, where t is the liquidus temperature in degree Celsius, A denotes the mass fraction of AlF3 in system Na3AlF6-K3AlF6- AlF3, and B denotes K3AlF6/(Na3AlF6+K3AlF6 ) in mass(%, the value was defined as KR in this paper). The composition limitations are 0<w(AlF3)<30%, and 0<KR<50%. The isothermal diagram of molten salt system Na3AlF6-K3AlF6-AlF3 was obtained in this composition limitation.



Nondriven polymer translocation through a nanopore: Scaling for translocation time with chain length

LI Hui, ZHANG Jing, LIU Hong* and SUN Chia-chung

2011, 27(6):  1023-1026. 

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We investigated the dynamics of the passage for a polymer chain through a nanopore in the absence of any external driving force with Weeks-Chandler-Andersen potential in two-dimensional simulations, in particular, focused our attention on the scaling law of the mean translocation time. We found that the effect of hydrodynamic interactions is the major factor in determining the scaling exponents with increasing pore size. The scaling close to N1+2v was observed when the hydrodynamic interactions were screened in the cases of small pore sizes, while the scaling close to N3v was obtained when the hydrodynamic interactions were present in the cases of large pore sizes.



Electrocarboxylation of Anthrone to Anthracene-9-carboxylic Acid in the Presence of CO2

ZHANG Li, WANG Huan*, ZHAO Jian-qing, CHEN Bao-li and LU Jia-xing

2011, 27(6):  1027-1030. 

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Electrocarboxylation of anthrone in the presence of CO2 to anthrance-9-carboxylic acid directly was carried out. The electroreduction behavior of anthrone was examined by cyclic voltammetry in the absence and presence of CO2. Then the influences of the supporting electrolytes, temperature, electrode material and anthrone concentration on the carboxylation yield were investigated. Under the optimized conditions, anthrancene-9-carboxylic acid was obtained in a good yield(96.1%).



Removing Cd2+ by Composite Adsorbent Nano-Fe3O4/Bacterial Cellulose

LU Min*, GUAN Xiao-hui and WEI De-zhou

2011, 27(6):  1031-1034. 

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A new composite adsorbent, nano-Fe3O4/bacterial cellulose(BC), was prepared through blending method. The process of adsorbing Cd2+ including its isotherm and kinetics measured was studied. The results show that the adsorption efficiency is improved because of huge surface area and surface coordination of nano-Fe3O4 particles. Its adsorption capacity is 27.97 mg/g and the maximum of Cd2+ removal is 74%. The adsorption kinetics can be described by pseudo-second rate model and the adsorption equilibrium by Langmuir type. The superparamagnetism of nano-Fe3O4 particles can help to solve the difficult separation of single BC adsorbent and lead to the quick separation of composite adsorbent from the liquid if a magnetic field was applied. Cd2+ can be desorbed effectively by EDTA and HCl from the composite adsorbent, which can make it be reused.



Adsorption of Anionic Dyes onto Chitosan-modified Diatomite

ZHANG Ge-shan, XUE Hong-hai, TANG Xiao-jian, PENG Fei and KANG Chun-li*

2011, 27(6):  1035-1040. 

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The purpose of this work is to study the possibility of anionic dyes Reactive Red M-8B(RR) and Direct Green B(DG) adsorbed on chitosan-modified diatomite. The characteristics of adsorbent, adsorption isotherms and the influence of adsorption time, temperature and pH were researched in this work. The results show that the mo-  dified diatomite had a much better adsorption capability than the natural diatomite. The adsorption capacities of   chitosan-modified diatomite for RR and DG were 94.46 and 137.0 mg/g, respectively. Both adsorption time and adsorption temperature provided a positive effect on the dye adsorption. Within the experimental pH range, the adsorbance was enhanced at lower pH but reduced sharply at high pH. On the basis of the experimental results and discussion, electrostatic attraction is considered as the main mechanism of this chemisorption.



Kinetics and Mechanism of Oxidation of 1,2-Butanediol or Mephenesin by Ditelluratocuprate(III) in Alkaline Media

SHAN Jin-huan*, LIU Yan-ping and FENG Shu-xia

2011, 27(6):  1041-1044. 

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The kinetics of the oxidation of 1,2-butanediol or mephenesin by ditelluratocuprate(III)(DTC) was investigated spectrophotometrically at temperatures between 283.2―303.2 K in alkaline media. The reaction rate showed first order dependence in DTC and fractional order in 1,2-butanediol or mephenesin. It was shown that the pseudo- first-order rate constant kobs increased with an increase in concentration of OH– and a decrease in concentration of TeO42–. The reaction has a negative salt effect. A plausible mechanism of reaction involving a pre-equilibrium of  adduct formation between the complex and 1,2-butanediol or mephenesin was proposed. The rate equations derived from the mechanism can explain all the experimental phenomena. The activation parameters for the rate-determining step were also calculated.



Preparation of Organic Nanoparticle Colloids by Laser Ablation and Their Nonlinear Optical Properties

YANG Jie, WANG Rui, DING Ran, LI Ai-wu, YU Yong-sen, WANG Ji-ping* and YANG Han*

2011, 27(6):  1045-1048. 

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Suspension of micrometer-sized 1,4-bis(4-methylstyryl)benzene(p-MSB) was converted into colloidal nanocrystal solution by irradiation with an femtosecond laser(800 nm, 1 kHz). The prepared nanocrystals were rectangular with ca. 100 nm in size. The same crystal structure as that of bulk crystals was confirmed by X-ray diffraction measurement. UV-Vis spectra and emission spectra of the nanoparticle dispersions in dichloromethane(poor solvent) were examined. The nanocrystal exhibits large quantum yield(89%). The nonlinear optical properties of the nanocrystals were further studied by Z-scan technique with femtosecond laser duration of 120 fs at a wavelength of 800 nm. The results show that the nanocrystals exhibit strong nonlinear absorption.



Non-enzymatic Glucose Biosensor Based on Cu/SWNTs Composite Film Fabricated by One-step Electrodeposition

SUN Fang, LIU Peng, LI Li and LIAN Yong-fu*

2011, 27(6):  1049-1054. 

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Based on the adsorption of copper ions on single-walled carbon nanotubes(SWNTs) in electrolyte, Cu/SWNTs nanocomposite film was initially prepared on indium-doped tin oxide(ITO) substrate by one-step    electrodeposition. This method may provide a versatile and facile pathway to fabricate other SWNTs-supported metal composite films. Electrochemical experiments revealed that the obtained Cu/SWNTs/ITO electrode offered an    excellent electrocatalytic activity towards the oxidation of glucose and could be applied to the construction of non-enzymatic glucose biosensor. The linear range of the sensor was 1.0×10–6 to 6.0×10–4 mol/L and the response time was within 2 s. Particularly, its sensitivity reached as high as 1434.67 μA·L·mmol–1·cm–2, which was superior to any other non-enzymatic glucose biosensor based on copper-carbon nanotubes electrode reported previously.



Influence of Molecular Interaction on Crystallization Behavior of Glycine from Mother Liquor

TAO Chang-yuan*, LI Ming-song, FAN Xing, LIU Zuo-hua and DU Jun

2011, 27(6):  1055-1059. 

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The mother liquor for preparing industrial HCN was investigated, to analyze the side-products’ structure and influence of molecular interactions of side-products with glycine and solvent on the glycine’s crystallization process. The side-products(SPs) were super-branched oligmers with plenty of hydrophilic groups, which could affect the crystallization process by interactions such as hydrogen bond. Alcohol-water mixed solvent with different polyols could be used to weaken the SPs-glycine interaction and strengthen the SPs-water interaction, which help to improve the crystallization efficiency and purity. After optimization, SPs’ mass fraction in glycine could be reduced by 80% and the morphology of crystal particles could also be improved.



Investigation on the Photodissociation of Oxygen from Oxymyoglobin by Fluorescence Spectroscopy

ZHOU Hua-wei, CAO Hong-yu, TANG Qian, MA Jun-yan, ZHANG Ying-ying and ZHENG Xue-fang*

2011, 27(6):  1060-1064. 

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Photodissociation of oxygen from oxymyoglobin(oxyMb) was investigated by means of fluorescence spectroscopy. One of the most important findings of the photodissociation of oxyMb was the discovery of two processes which were affected by excitation intensity, temperature, solvent viscosity, and excitation wavelength. Process I(PI) corresponded to oxygen escaping from the binding site at ferrous heme iron atom within the porphyrin ring into the heme pocket, whereas process II(PII) was ascribed to oxygen escaping from the heme pocket into the solvent. To elucidate this interesting phenomenon, we proposed a model that oxygen encountered two barriers on its way from the binding site at the ferrous heme iron to the solvent. Reversibility and wavelength sensitivity of the photodissociation were also observed.



Dielectric Spectra of Aerosol OT/Water Systems at Different Concentrations and Temperatures

ZHAO Kong-shuang*, JIA Zhan-jie, YANG Li-kun and XIAO Jin-xin

2011, 27(6):  1065-1071. 

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The dielectric spectra of aerosol OT[AOT, sodium(bis-2-ethylhexyl)sulfosuccinate]/water systems at different concentrations and temperatures were investigated by the dielectric relaxation spectroscopy(DRS). Through the dielectric spectra of different concentrations, two dielectric relaxations were observed over a frequency range from 40 Hz to 110 MHz and the mechanisms of the relaxations were also interpreted based on the Grosse’s model. The low-frequency relaxation(around 105 Hz) was  attributed to the radial diffusion of counterions along the long-half axis of the rod-like micelle, and the high-frequency relaxation(around 106 Hz) was ascribed to the radial diffusion of counterions along the short-half axis. Furthermore, specific emphasis was placed on studying the effects of temperature on system’s conductivity. It was observed that the low-frequency limit of conductivity(κl) decreased and then increased with the increment of temperature under the measured concentration. On the other hand, the conductivity(κm and κh) in meso- and high-frequency ranges always increased as temperature increased. Both the tendencies of alteration which mentioned above should be related to the phase transition of AOT/water system.



Synthesis and Antibacterial Action of Poly(DMAEMA-BC) with Various Molecular Weights

LU Gui-qian, ZUO Hua-jiang, DONG Wei-min, WU Ding-cai and FU Ruo-wen*

2011, 27(6):  1072-1077. 

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Antibacterial polymers of dimethylaminoethyl methacrylate benzyl ammonium chloride(DMAEMA-BC) with various molecular weights(Mws) were prepared under controlling radical polymerization conditions. The Mws of these polymers were determined by means of static multiangle laser light scattering and viscosity method. A Mark-Houwink equation was established to be [η]=0.154M0.764 for the Mw evaluation of poly(DMAEMA-BC)s. The effects of the Mws of these poly(DMAEMA-BC)s on their antibacterial activities against E. coli and S. aureus were investigated by various methods including viable cell counting, electrical conductivity titration, intracellular constituent leakage tests and electron microscopy. Our results indicate that the antibacterial efficiency of DMAEMA-BC was significantly enhanced after the monomers were polymerized into a polymer and increased obviously with the Mws，as a result of the increase of charge density. Further investigation of the molecular basis underlying the    anti-bacterial role of these polymers revealed that poly(DMAEMA-BC) promoted the release of potassium ion from the membrane of bacterial cells and the release increased significantly with the Mws of the polymers used.



PEG-grafted PVA Membrane and Its Blood Compatibility

JIN Gu*, YAO Qi-zhi, DONG Li-quan and MA Feng

2011, 27(6):  1078-1082. 

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Preparation and blood compatibility of different shape polyvinyl alcohol(PVA) membrane were investigated. Firstly, the tabular and tubular[polytetrafluoroethylene(PTFE) capillary as supporter] PVA membranes were prepared; then, methoxy polyethylene glycol(mPEG) was grafted onto the surface of the PVA membranes. The effects of the shape, structure and properties of the membrane surface on blood compatibility were studied in detail. The  experiment results show that mPEG modified PVA membranes, especially mPEG modified tubular membrane, could availably repel the adhesion of the platelets. In addition, the anticoagulant mechanism of mPEG with a steric repulsion effectiveness was confirmed further via different grafting methods.