Table of Content

10 June 2011, Volume 32 Issue 6

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Contents

Cover and Content of Chemical Journal of Chinese Universities Vol.32 No.6(2011)

2011, 32(6):  0. 

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Letters

Electrochemical Behavior of  Isocyanate as Novel Film-forming Additive in Electrolytes

XIANG Jin, CHEN Ren-Jie*, WU Feng, LI Li, CHEN Shi

2011, 32(6):  1231-1233. 

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New sulfone-isocyanate mixed electrolytes based on tetramethylene sulfone (TMS) and p-toluenesulfonyl isocyanate (PTSI) were prepared, and their physiochemical properties and their electrochemical behaviors on the mesocarbon microbeads electrode (MCMB) were investigated by galvanostatic charge-discharge and cyclic voltammetry (CV). The results show that the electrochemical window of the electrolytes are over 5.0 V. Moreover, the mixed electrolytes even perform good thermal stability. Compared with pure TMS-based electrolytes, the mixed electrolytes show better wettability and improved lithiation/delithiation reversibility. The Li/MCMB half-cell exhibits a specific capacity of over 360 mAh/g with excellent capacity retention after 50 cycles when combined with a composite electrolyte containing 5 vol% PTSI because an effective solid electrolyte interface layer is thought to form. The energies of the lowest unoccupied and highest occupied molecular orbitals of PTSI are lower than those of TMS and vinylene carbonate, indicating that PTSI molecules can accept electrons readily and possess a high oxidation potential.



Articles

Preparation and Characterization of Hydroxyl Functional Compound with Covalent Organic Framework

PEI Cui-Ying, QU Feng-Yu*

2011, 32(6):  1234-1238. 

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A microporous covalent organic framework (COF) has been designed and synthesized via nickel (0)-catalyzed Yamamoto-type Ullmann cross-coupling reaction. Tri(4-bromophenyl)silanol has been employed as monomer and the structure was determined using MAS NMR, FTIR, SEM and PXRD. The functional structure exhibits not only high thermal stability （467 ℃），high chemical stability but also large surface area (958 m2g-1), and the pore size is 1.27 nm.



Synthesis, Characterization , Crystal Structures and Catalytic Performance of 2,6-Bis(imino)pyridyl Manganese Complexes

FAN Rui-Qing*, YUAN Guo-Hui, DING Xiao-Dong, CHEN Jie, YANG Yu-Lin*

2011, 32(6):  1239-1243. 

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Reactions of equimolar rations of MnCl2?4H2O and the tridentate ligands 2,6-bis[1-(2,6-dimethylphenylimino)ethyl]pyridine (L1), 2,6-bis[1-(2,6-diethy phenylimino)ethyl]pyridine (L2), and 2,6-bis[1-(2,6-dimethylphenylimino)ethyl]pyridine(L3) in acetonitrile afford the five-coordinated complexes L1Mn(II)Cl2?CH3CN(Mn1), L2Mn(II)Cl2?CH3CN(Mn2) and L3Mn(II)Cl2?CH3CN(Mn3), respectively. All complexes were characterized using elemental analysis, IR spectroscopy and single-crystal X-ray diffraction. Crystallographic studies on complexes Mn1–Mn3 reveal three complexes to be pentacoordinate with geometries that can be best described as distorted trigonal bipyramidal. Mn1 crystallizes in the monoclinic system, space group P21/n, with a = 1.3304(3) nm, b = 1.4864(3) nm, c = 1.4423(3) nm; β = 108.41(3)?, V = 2.7063(9) nm3, Z = 4, F(000) = 1116 , R1 = 0.0465. Mn2 belongs to monoclinic system with space group P21/c, with a = 1.2919(1) nm, b = 1.5283(1) nm, c = 1.6362(1) nm; β = 99.27(1)?, V = 3.1883(3) nm3, Z = 4, F(000) = 1244, R1 = 0.0599. Mn3 belongs to monoclinic system with space group P21/n, with a = 1.4542(3) nm, b = 1.5083(3) (1) nm, c = 1.4646(3) nm; β = 112.56(3)?, V = 2.9667(10) nm3, Z = 4, F(000) = 1180, R1 = 0.0627. Complexes Mn1–Mn3 exhibit lower catalytic activities for ethylene polymerization after activation with cocatalysts of [Ph3C]+[B(C6F5)4]-.



Preparation and Characterization of Two GdCl3-galactitol Complexes

YU Lei, HUA Xiao-Hui, ZHAI Yan-Jun*, YANG Li-Min*, ZHAO Guo-Zhong, MENG Tian-Hua, WENG Shi-Fu, XU Yi-Zhuang, LIU Ke-Xin, WU Jin-Guang, CHEN Jia-Er

2011, 32(6):  1244-1249. 

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Coordination of hydroxyl groups to metal ions is common in biosystems. Here two GdCl3-galactitol complexes have been prepared, one is 2GdCl3?C6H14O6?14H2O, in which Gd3+ is coordinated to three hydroxyl groups of galactitol and six water molecules, other water molecules are hydrogen-bonded and chloride ions do not coordinate to metal ions. It is possible that Gd3+ is 9-coordinated to six hydroxyl groups from two galactitol molecules and three water molecules, the ratio of metal to galactitol is 1:1 and maybe several water molecules are hydrogen-bonded in the second GdCl3-galactitol complex according to IR, elemental analysis, FIR, THz and TGA results. The experimental results indicate that two lanthanide-galactitol complexes can be obtained, which demonstrate the complexity of the interactions between metal ions and hydroxyl groups.



Synthesis, Structures and Density of State of Oxalate-bridged Dinuclear Cd(Ⅱ) Complex: [Cd2(phen)2ox(NO3)2 (H2O)2]

2011, 32(6):  1250-1254. 

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A dinuclear Cd(Ⅱ) complex [Cd2(phen)2OX(NO3)2(H2O)2] was synthesized by mixing potassium oxalate(K2OX?H2O), cadmium nitrate(Cd(NO3)2?4H2O) and 1,10-phenanthroline(phen) in methanol-water solution. The structure was characterized by X-ray single-crystal diffraction analysis. It belongs to triclinic system, space group with P-1 with a = 0.67629(14) nm, b = 1.0051(2) nm, c = 1.0527(2) nm, α = 109.19(3)°, β = 92.12(3)°, γ = 93.48(3)°, V = 0.6733(2) nm3, Z = 1, D = 2.055 g?cm-3, F(000) = 410, μ = 1.660 mm-1, R = 0.0445, wR = 0.0877. The analytical results indicate that it is an oxalate-bridged dinuclear Cd(Ⅱ) complex, the midpoint of carbon-carbon bond of oxalate is the center of inversion for the complex, Cd(Ⅱ) cation coordinates with OX2-, phen, NO3- and H2O. The crystal field theory was used to calculate density of state (DOS) for the complex, analysis shows that NO3- and phen have important influence on the properties of the complex.



Preparation of ZnO@CeO2 Nanocables by Coaxial Electrospinning

XU Shu-Zhi, DONG Xiang-Ting*, GAI Guang-Qing, LIU Gui-Xia, WANG Jin-Xian, LU Tong-Xiao

2011, 32(6):  1255-1260. 

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ZnO@CeO2 coaxial nanocables were successfully synthesized by coaxial electrospinning using cerous nitrate, zinc nitrate, polyvinyl pyrrolidone, N, N-dimethylformamide, glycerin and chloroform as starting materials. The samples were characterized by thermogravimetry and differential thermal analysis, X-ray diffractometry, scanning electron microscopy，transmission electron microscopy and energy dispersive spectroscopy techniques. The results show that ZnO@CeO2 coaxial nanocable with a diameter of ca.90 nm，core diameter of ca.60 nm and shell thickness of ca.15 nm. The nanocables has a core of crystalline ZnO and a shell of crystalline CeO2. The length of the ZnO@CeO2 nanocables is greater than 300 μm. The formation mechanism of the ZnO@CeO2 nanocables is preliminarily investigated.



Synthesis and Anti-Fake Function Design of Multiple Luminescent CdxZn1-xSe Quantum Dots

BAI Xue-Lian*, DU Ji-Yan, ZENG Jie, WU Bin, YU Xu-Dong, FANG Ling-Hui

2011, 32(6):  1261-1265. 

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The single crystals of CdxZn1-xSe were prepared by chemical transport method. We change the luminescence center of the information carrier through adjusting the composition of the alloy quantum dots. The alloyed nanocrystlas show composition-tunable optical band gap energy and their emission can be tuned continuously in the range of 524 to 627 nm．Here,we discussed the multicolor optical coding for engineering assays through coating different-colored quantum dots onto the anti-fake label,which further resulting in a new security identification system. The multiple luminescent CdxZn1-xSe quantum dots based anti-fake system can be applied to supermarket labeling,military security and object identification.



Treament of Nitrobenzene Wastewater with Ti/PbO2-La Electrode

LIU Nan, LIU Miao*, JIAO Xin-Qian, LIU Xin, LENG Su, CHEN Li-Ke

2011, 32(6):  1266-1271. 

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By using electro-deposition Ti-PbO2-La electrodes, visited different La-doped electrodes for electrochemical oxidation of the formation of ?OH. Combined with SEM and XRD, found that La-doped in electroplating solution enables active electrode layer occurs enlarges electrode structure changes, while increasing the stability of hydroxyl radicals generated in more degradation. Experiments show when the doping of 0.015mol/L of electrodes to simulated water treatment efficiency. Meanwhile, the change of nitrobenzene, CODcr concentration and current intensity, pH, initial concentration is associated. The best treatment actual water conditions: I = 0.9A, pH = 5, d = 1cm.When started with the NB (ρ) is 322.7mg \ L and CODcr is 1730mg / L, after the reaction of 3h, the NB (ρ) is less than 0.2mg / L, CODcr is less than 40mg / L, which meet the national emission standards.



Surface Modification for Epoxy Resin Based Microfluidic Chip

WANG Lin-Lin, HUANG Jiang, JIN Wei, JIN Qin-Han, MU Ying*

2011, 32(6):  1272-1276. 

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Microfluidic devices are potentially useful for biomedical detection， which sometimes need to be modified on the surface to immobilize active biomolecules. Surface modification of air-plasma-pretreated epoxy resin via near UV-induced graft polymerization with acrylic acid (AAc) was carried out. Specific antibodies were covalently immobilized on the surface of epoxy resin which were used to immunological detection. The modified epoxy resin were characterized by static water contact angle measurement, toluidine blue O staining test, X-ray photoelectron spectroscopy (XPS), bicinchoninic acid (BCA) test, and cell attachment. Our studies showed that the carboxyl groups were grafted onto the surface of epoxy resin, and covalently crosslinked with proteins. The results of cell attachment revealed that the modified epoxy resin could be applied to immunological detection.



Interaction of  Rhein-Cu(Ⅱ) Complexes with Bovine Serum Albumin

ZHAO Fang*, LIANG Hui, CHENG Hui, WANG Jun, ZHAO Wen-Hui

2011, 32(6):  1277-1283. 

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The interaction between rhein-Cu and bovine serum albumin(BSA) was investigated by fluorescence and ultraviolet spectroscopy. The results indicated that rhein-Cu led to the intrinsic fluorescence quenching of BSA through a static quenching procedure. The binding constants KA and binding site n at 298 K and 309 K were obtained. The binding locality was found to be an area 3.24 nm away from tryptophan residue in BSA based on F?rster non-radiation energy transfer mechanism. The experimental results showed that the rhein-Cu could be inserted into the BSA, quenching the inner fluorescence by forming the rhein-Cu-BSA complex. The binding power between rhein-Cu and BSA is mainly the hydrophobic interaction according to the thermodynamic parameters. The effect of rhein-Cu on the conformation of BSA was analyzed by circular dichroism(CD) and synchronous fluorescence spectra.



Interaction of Chemosensory Proteins of Apis cerana cerana with Special Ligands by Fluorescence Spectroscopy

LI Hong-Liang, ZHANG Lin-Ya, ZHU Li-Yun, NI Cui-Xia, SHANG Han-Wu*

2011, 32(6):  1284-1288. 

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The interactions of separated and purified recombinant Chemosensory proteins 3 (CSP3) of Chinese honeybee, Apis cerana cerana with its special ligands, N-Phenyl-1-naphthylamine (1-NPN) was investigated with the method of fluorescence spectroscopy. The results showed that 1-NPN could quench the intrinsic fluorescence of CSP3 at 328 nm (λem) by static quenching and hydrophobic interaction was the predominant intermolecular force, and the binding distance (r = 9.3 nm) and energy-transfer efficiency (E = 0.054) bewteen donor (CSP3) and acceptor (1-NPN) were obtained according to the F?rster-type dipole-dipole nonradiative energy-transfer mechanism. In addition, from the results of synchronous fluorescence spectroscopy, the tryptophan residue contributed the main fluorescent emission, and with its λmax turnning to red shift, it indicated that 1-NPN can affect the the conformation of CSP3, and increase the polarity of tryptophan residue in the hydrophobic cavity of CSP3.



Rapid Detection of Ginsenosides Using NanoEESI-MS

HU Bin, YUE Hao, HUANG Ke-Ke*, JIANG Cui-Cui, LIU Shu-Ying, FEI Qiang, CHEN Huan-Wen*

2011, 32(6):  1289-1294. 

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A rapid approach to detect ginsenosides has been developed based on nano electrospray extractive ionization (NanoEESI) tandem mass spectrometry. The raw extract of ginseng roots were directly introduced to the gasless nanoEESI source for production of sodiated ions of ginsenosides, without any chromatographic separation. The signals of sinsenosides [M+Na]+ were identified by tandem mass spectrometry. The characteristic fragmentation patterns were therefore used as the molecular markers to differentiate ginseng roots from platycodon grandiflorum and phytolacca acinosa rox, where are two typical plant roots illicitly used as ginseng roots on the herb medicine market. Acceptable sensitivity, reproducibility and fast speed were obtained for the samples tested, showing that nano extractive electrospray ionization tandem mass spectrometry is a useful technique for fast screening ginseng products or other traditional Chinese medicinal materials.



125I-AIBZM Nanoliposomes  Targeting Brain as Imaging Agents

LI Guang-Hui, SHEN Hai-Xing, QIAN Jun, SI Zhan, ZHU Jian-Hua*

2011, 32(6):  1295-1300. 

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The aim of this study is to develop a blood brain barrier (BBB) permeable nano-liposome drug delivery system that significantly up-regulates the brain uptake of (S)-5-125I-N-(1-ethyl-2-pyrrolidinyl)methyl-4-amine-2-methoxy-benzamide (125I-AIBZM) as an imaging agent. Both 125I-AIBZM-nanoliposome (125I-AIBZM-L) and 125I-AIBZM-lactoferrin-nanoliposome (125I-AIBZM-Lf-L) were prepared by the ammonium sulfate gradient method with a small particle size (~100 nm) and a narrow size distribution pattern. The encapsulation efficiencies of 125I-AIBZM-L and 125I-AIBZM-Lf-L were measured as 39% and 35% respectively. In vivo fluorescence imaging results showed that DIR-Lf-L successfully delivered drug into the brain. The pharmacokinetic experiments in rats indicated that the blood circulation times of 125I-AIBZM-L and 125I-AIBZM-Lf-L were substantially longer than that of small molecular 125I-AIBZM. Amount of intracerebral 125I-AIBZM delivered by 125I-AIBZM-L was significantly lower than 125I-AIBZM-Lf-L (p <0.01) but remarkably higher than that of 125I-AIBZM (p <0.01). Conclusion: 125I-AIBZM-Lf-L nano-liposome drug delivery system can increase the brain uptake of imaging agent 125I-AIBZM.



Condensation of 2-Substituted-4-formyl-1,2,3-triazole with β-Cyclohexanedione Catalyzed by Mg(ClO4)2

LIU Chen-Jiang*, ZHAO Xin-Hai, WANG Zhao-Shen

2011, 32(6):  1301-1304. 

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The condensation reaction of 2-substituted-4-formyl-1,2,3-triazole instead of the ordinary aldehydes with β-cyclohexanedione was investigated by acrylonitrile as a reaction medium, employing Mg(ClO4)2 as the catalyst. It was found that when it was carried out in the presence of Mg(ClO4)2, its selectivity gave the xanthenes. Further study showed that without additional catalyst this reaction could give xanthenediones ring-opening derivatives.



Synthesis and Crystal Structure of 3-Ferrocenyl-5-aryl-1-benzenesulfonyl Dihydropyrazole Derivatives

LI Chun-Yan, ZHUO Ji-Bin, XIE Li-Li, LI Heng-Dong, WANG Wen-Feng, YUAN Yao-Feng*

2011, 32(6):  1305-1311. 

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Two Novel 3-diferrocenyl dihydropyrazole derivatives were synthesized from corresponding α,β-unsaturated ketones. The structures of these compounds were characterized by IR, 1H NMR spectra and X-ray single crystal diffraction. The crystal structure of compound 3a belongs to the orthorhombic,space group P2(1)2(1)2(1) with the lattice parameters a = 0.59466(12) nm，b = 1.9402(8) nm，c = 3.1274(6) nm，α = 90.00°，β = 90.00°，γ = 90.00°，Z = 4，F(000) = 1280，DC = 1.442 g/cm3，μ = 0.817 nm-1. Its crystal structure showed that chain-like one-dimentional structure was formed along a axis by the intermolecular hydrogen bonds.The compound 3b belongs to the monoclinic, space group P2(1)/c,and its lattice parameters are as follows: a = 1.3087(3) nm，b = 0.9844(2) nm，c = 1.7752(4) nm，α = 90.00°，β = 99.42(3)°，γ = 90.00°，Z ＝ 4，F(000) = 1112.0，DC = 1.617 g/cm3，μ = 2.558 nm-1. The intermolecular hydrogen bonds between the sulfonyl oxygen and nonsubstituted cyclopentadienyl (Cp) hydrogen and bromobenzene hydrogen led to the formation of stable supermolecular structure of one 3b with three otherwise 3b molecules.



Synthesis and Biological Activities of Derivatives of 3,6-Diphenoxymethyl-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazoles

SUN Xiao-Hong*, BAI Yan, LIU Yuan-Fa, CHEN Bang, JIA Ying-Qi

2011, 32(6):  1312-1317. 

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4-amino-2,4-dihydro-5-(phenoxymethyl)-3-mercapto-3H-1,2,4-triazole and substituted phenoxyacetic acid refluxed in POCl3 to afford 3,6-diaryloxymethene -1,2,4-triazolo[3,4-b]-1,3,4-thiadiazoles. The chemical structures of the compounds were confirmed by 1H NMR, IR and elemental analysis. The preliminary toxicity testing of all the target compounds were investigated. The results showed that they exhibited melt fungicidal activities.



Three New Terpenoids from Salvia przewalskii Maxim.

YANG Yang, WU Zhi-Jun, YANG Ying-Bo, LAI Wei, SUN Lian-Na, CHEN Wan-Sheng*

2011, 32(6):  1318-1322. 

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Salvia przewalskii Maxim. (Labiatae) is widely distributed in the western areas of China, such as Gansu, Sichuan, Yunnan and Tibet provinces. And it has been used as a substitute in Chinese folk medicine for S. miltiorrhiza Bge. (Dan Shen). The mainly chemical constituents of S. przewalskii are diterpenoids and phenolic acids. In our search, isolation and purification were carried out repeatedly by silica gel, Sephadex LH-20, ODS C18 and MCI gel column chromatography. Two new diterpenoids, named ganxintriol A (1) and ganxintriol B (2), and a new monoterpenoid glycoside, named ganxinoside A (3), were obtained from 50% ethanol extract of the roots and rhizomes of S. przewalskii. Their structures were established on the basis of physical methods, chemical methods and spectral data.



Preparation of 3DOM Periodic Composite Ag/ZnO-TiO2 and Microwave-assisted Photocatalytic Performance

LI Li, ZHAO Yue-Hong, LI En-Shuai, ZHUO Na, MA Hui-Yuan*, LIU Bo*

2011, 32(6):  1323-1329. 

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Three-dimensionally ordered macroporous composite Ag/ZnO-TiO2 was prepared by the sol-gel method combined with a polystyrene (PS) latex sphere templating technique and calcined. The phase structures, chemical composition, optical absorption properties and surface physicochemical properties were well-characterized via a Fourier transform infrared (FT-IR) spectrum, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Transmission electron microscopy (TEM), N2 adsorption-desorption tests and scanning electron microscopy assisted X-ray energy dispersive spectroscopy (SEM-EDS). Results showed that produced composite Ag/ZnO-TiO2, which by using polystyrene (PS) latex sphere, had anatase crystalline structre, well distribution, good struction and the silver species in the Ag/ZnO-TiO2 was metallic Ag. Moreover, the walls structure of the 3DOMAg/ZnO-TiO2 was mesoporous with compact walls, and the average pore diameters were ca.150 nm, which were three-dimensional ordered macroporous materials (3DOM). The photocatalytic activities of Ag/ZnO-TiO2 were tested by microwave assisted photocatalytic degradation of the dyes, for example, methyl orange. Results showed that this composite material had fine photocatalytic activities for many dyes, and the activity was higher than that of P25 and binary system ZnO-TiO2



Reaction Mechanism and Hydrogen Storage Properties of LiAlH4 and LiNH2

REN Xiao, WANG Xin-Hua*, LI Shou-Quan, GE Hong-Wei

2011, 32(6):  1330-1333. 

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LiAlH4 and LiNH2 was ball milled at molar ratio of 1:2, thus prepared composite was heated for dehydrogenation, the fully dehydrogenated samples were re-hydrogenated. The dehydrogenation/re-hydrogenation processes were studied by means of XRD, DSC and FTIR analysis. The experimental results showed that the dehydrogenation process of LiAlH4/2LiNH2 composite is a three-stage reaction, and Li3AlN2 was formed after releasing 8.65wt% of hydrogen。The derived Li3AlN2 can be re-hydrogenated under conditions of 10MPaH2 and 400℃, and LiNH2 、AlN and LiH were formed. The reversible hydrogen storage capacity reached 5.0wt%. The dehydrogenation/re-hydrogenation mechanism of LiAlH4/2LiNH2 composite was discussed.



Synthesis of Bimetallic Modified Mesoporous Material and Its Application in Catalysis

JIANG Yan-Qiu, LIN Kai-Feng*, LIU Jie2, SUN Jian-Min, XU Xian-Zhu, XIAO Feng-Shou*

2011, 32(6):  1334-1338. 

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Bimetallic (Sn/Ti) modified mesoporous material with thermally stable and highly active Ti-sites (Sn/Ti-MS-1) was synthesized by the assembly of Sn-incorporated TS-1 precursor with surfactant in acidic media. The characterization results indicated that the material has typical mesostructure and that the mesoporous framework contains zeolitic building units. In the oxidation of phenol and 2,3,6-trimethylphenol with aqueous H2O2, as-synthesized and calcined Sn/Ti-MS-1 both showed good catalytic conversions, indicating that the active Ti-sites are highly thermally stable and that the material is favorable in the oxidation of bulky substrates. Also, Sn/Ti-MS-1 displayed high reaction rate in the oxidation of 2,3,6-trimethylphenol.



Chiral Selectivity of Arginase Ⅰ

LI Shuai, LI Zhao-Long, HU Yu-Lin, GAO Xue-Feng*, HUANG Xu-Ri

2011, 32(6):  1339-1342. 

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In this study，the chiral selectivity of arginase was investigated by means of molecular dynamics and molecular docking. According to comparing the L-type arginine–arginaseⅠcomplex and D-type arginine–arginaseⅠcomplex, it was observed that L-type arginine–arginase complex had higher stability. From the results of the molecular dynamics trajectories of two complexes, it was shown that the L-type Arginine–Arginase complex had a RMSD curve with less shock and higher energy level than the D-type Arginine–arginase complex. Above all, the conclusion was drawn that the chiral selectivity of Arginine in the catalytic reaction was thoroughly depended on the structure of the enzyme active domain.



TD-DFT Studies on Phenothiazine-based Dyes with Different Donor in Dye-sensitized Solar Cells

ZHANG Ji, LI Hai-Bin, WU Yong, GENG Yun, DUAN Yu-Ai, LIAO Yi*, SU Zhong-Min*

2011, 32(6):  1343-1348. 

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To shed light on the effects of the donor part in organic dyes on the energy conversion efficiency of dye-sensitized solar cells (DSSCs), Density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations were carried out to gain insights into the photophysical properties and the parameters of electron injection and transfer for the ground and excited states of phenothiazine-based dyes before and after binding to titanium dioxide(TiO2). The theoretical results reveal that the exciton binding energy Eb and the free energy change ΔGint for the electron injection of the dyes are crucial in determining the energy conversion efficiency of DSSCs when these dyes have the similar absorption spectra,i.e vertical transition energies and oscillator strength. We hope our conclusions would play a theoretical guiding role in the design and synthesize of new organic dyes.



Electrocatalytic Oxidation of Formic Acid on the Carbon Supported Pd-Ni Alloy Nanoparticles

XI Cai-Ming, SHI Yi, ZHAO Jia-Yue, ZHOU Yi-Ming*, TANG Ya-Wen, CHEN Yu*, LU Tian-Hong

2011, 32(6):  1349-1353. 

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Formic acid electrooxidation on Pd catalysts has been extensively investigated due to potential application in direct formic acid fuel cells. To improve the stability of catalysts and promote formic acid electrooxidation through the direct pathway, various Pd-based bimetallic catalysts has been received much attentions. In this work, the carbon-supported Pd-Ni (Pd-Ni/C) catalysts with different Pd/Ni atomic ratios are prepared by the impregnation-reduction method. These catalysts are characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS). The resulting physicochemical characterizations indicate that particle size, crystal structure and electron structure of Pd nanoparticles by adding Ni element. In addition, the effect of Pd/Ni atomic ratios on electrocatalytic performance of Pd-Ni/C catalysts for formic acid electrooxidation is also demonstrated by several electrochemical measures. It is observed that Pd-Ni/C catalyst with the suitable Pd/Ni atomic ratio exhibits excellent electrocatalytic performance and stability for the formic acid electrooxidation.



Asymmetric Hydrogenation of α-Ketoesters on Chirally Modified Pt Catalysts Supported on MPC-61 Ordered Mesoporous Carbon

LI Kai-Xiang, LI Xiao-Hong*, SONG Li-Ying, WU Peng

2011, 32(6):  1354-1359. 

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4% and 10% (mass fraction) Pt catalysts supported on MPC-61, a kind of ordered mesoporous carbon, were prepared by an impregnation method using two different Pt precursors, ethanolic solution and aqueous solution of H2PtCl6. These Pt/MPC-61 catalysts were characterized by XRD, N2-sorption, TEM and CO chemisorption. The Pt/MPC-61catalysts proved to be efficient in the asymmetric hydrogenation of ethyl pyruvate after chirally modified with cinchonidine. The Cat-4Pt-E catalyst derived from the ethanolic solution of H2PtCl6 afforded better conversions of ethyl pyruvate due to smaller Pt particle size with higher Pt dispersion. While the Cat-4Pt-W catalysts derived from the aqueous solution of H2PtCl6 showed higher chiral induction ability. The catalyst Cat-4Pt-W-150 that was calcined at 150 oC under vacuum gave higher conversion and higher enantioselectivity than Cat-4Pt-W did, the highest TOF reaching 8820 h-1 in water. A 66% ee value was furnished by Cat-10Pt-E catalyst in acetic acid. In particular, the Cat-4Pt-W catalyst showed superior catalytic activity to the commercial Pt/C catalyst, mainly due to the ordered mesoporous structure features of MPC-61 support. The 4% Pt catalysts supported on MPC-61 can also be effectively applied in the asymmetric hydrogenation of ethyl 2-oxo-4-phenylbutyrate, of which the hydrogenation product can be used to produce A.C.E inhibitors. Under the optimal conditions, the catalyst Cat-4Pt-W-150 gave a 61% ee value of (R)-(+)-ethyl 2-hydroxyl-4-phenylbutyrate.



Comparison of Catalytic Performances Between Complete Liquid-phase’s Catalyst and Sol-gel’s Catalyst for Slurry Synthesis Dimethyl Ether

FAN Jin-Chuan, HUANG Wei*, JI Peng

2011, 32(6):  1360-1365. 

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The Cu-Zn-Al bifunctional catalysts were respectively prepared by complete liquid-phase method and sol-gel method. The properties of catalysts were characterized by XRD, N2 adsorption and XPS, and the catalytic performance of catalysts for DME synthesis directly from syngas in a slurry reactor was evaluated. The results show that Cu species and surface Cu content in catalysts have obvious difference, but texture properties are similar. The catalyst prepared by complete liquid-phase method has high selectivity and good stability, and the catalyst specific surface area, pore volume, surface Cu content and Cu/Zn mole ratio increase after reaction. The catalyst prepared by sol-gel method has obvious deactivation, and average deactivation rate is 1.62 %/d. The decrease of specific surface area, pore volume, surface Cu content and Cu/Zn mole ratio after reaction are the reason of catalyst deactivation.



Structure and Catalytic Active Center of High Catalytic Activity CuY  Catalysts in Oxidative Carbonylation of Methanol

LI Zhong*, FU Ting-Jun, WANG Rui-Yu, NIU Yan-Yan, ZHENG Hua-Yan

2011, 32(6):  1366-1372. 

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In the preparation of CuY catalysts by ion-exchange of NaY zeolite with aqueous solution of copper nitrate, ammonia was added to the ion-exchange solution to adjust the pH and the ion-exchanged CuY was activated by high temperature calcination.The prepared CuY catalysts exhibited high catalytic active in the oxidative carbonylation of methanol to dimethyl carbonate. Compared with Cu catalysts prepared by solid-state ion-exchange, precipitation and impregnation, CuY catalysts loaded less Cu but showed good catalytic performance. Based on the characterization of the microstructure of CuY catalysts by XRD, XPS, AES, H2-TPR and elementary analysis, it was shown that by adding ammonia into the ion-exchange solution，the ion-exchanged reaction was promoted, resulting in the increase of the ion-exchanged Cu2+ and the most of Cu2+ in the supercage of CuY catalyst. In the process of calcinating activation of CuY catalysts in inert atmosphere, Cu2+ was auto-reduced to Cu+ and ammonia promoted the auto-reduction, which was conducive to the improvement of catalytic activity. The high activating temperature facilitated the auto-reduction progress of Cu2+ to Cu+ located in the supercage of zeolite, Cu+ content in the supercage of zeolite increased more quickly and the catalytic activity of CuY catalysts increased in the meantime. It was concluded that Cu+ in the supercage of Y zeolite was the main catalytic active center.



Preparation and Mechanism of Carbon Supported Pt Catalyst Using Pt(NO3)2 and Ethylenediaminetetraacetic Acid

XIE Guo-Fang, LU Tian-Hong, YANG Gai-Xiu, CHEN Yu, ZHOU Yi-Ming, TANG Ya-Wen*

2011, 32(6):  1373-1377. 

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During the preparation of carbon supported Pt (Pt/C) catalyst using Pt(NO3)2 as the precursor, ethylenediaminetetraacetic acid (EDTA) can effectively reduce the average diameter of the Pt particle and improve the dispersion degree. This effect is not due to that EDTA coordinates with Pt2+, forming the complex, but due to that EDTA would wrap Pt2+ through the electrostatic interaction. The average diameter of the Pt particles in the Pt/C catalyst obtained is only 3 nm and the dispersion of the Pt particles is uniform. Therefore, the Pt/C catalyst obtained has the excellent electrocatalytic activity and stability for methanol oxidation.



Liquid-Solid Equilibrium of Na⁺, K⁺, Mg²⁺//Cl^-, SO^2-₄, NO^-₃, H₂O System at 25 ℃

HUANG Xue-Li*, WANG Xue-Feng, CHEN Li-Juan

2011, 32(6):  1378-1383. 

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In this work, the liquid-solid equilibrium for the Na+, K+, Mg2+//Cl-, SO42-, NO3-, H2O system，to which the nitrate brine in Xinjiang in China belongs, is investigated for the first time; The solubilities in phase equilibrium of this system have been measured by isothermal method, and according to experimental data, the phase diagram was plotted. The results show: when saturated with NaCl and at 25℃, in this system, there are 8 double salt, 15 regions saturated with two salts, and 25 invariant points, one of which is an incongruent point saturated with Mg(NO3)2?6H2O、NaCl、MgCl2?6H2O、MgSO4?(1～6)H2O、KCl?MgCl2?6H2O, and others are reaction points. Based on these works, the sequence of crystallization of salts from the brine during evaporation process was discussed.



Useful Power Loss Led by Temporal Self\|organization Appearing in Electro-chemical Oxidation System of Formic Acid on Pt-electrode

LIN Feng, LUO Jiu-Li*

2011, 32(6):  1384-1388. 

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The research of power loss origining from the dissipation-fluctuation in electro-chemical oscillation appearing in the irreversible electrode processes is of special importance for the extension of applied electro-chemistry. In this paper both the threshold of potential oscillation and the trajactories of limit cyccle beyond it in the electro-chemical oxidation system of formic acid on Pt has beeb analysed and computed by using nonlinear systematical dynamics under the assumption that the electrochemical reaction steps are dominate. Furthermore, by means of the dissipation – fluctuation theory of polarization based on stochastic thermodynamics the polarization curves, as well as the spectrum of power loss in both the critical regime and the temporal self-organization regime have been also obtained. It tunns out that the spectrum of power loss per unit electrochemical reaction will abruptly decrease during the current density (externally controlled ) crossing its threshold (Hopf bifurcation point ). Following with the appearance of the temporal self-organization the average power loss per unit electrochemical reaction per period still increase with the current, however it keeps at a level lower than that before threshold until the current arrives to certain high extent.



Synthesis and Micelle Characterization of Amphiphilic MPEG-Drug Conjugate Used in Drug Delivery System 

LIANG Hai-Yan, WU Xue, JIN Hui-Juan*

2011, 32(6):  1389-1395. 

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An amphiphilic dendritic drug carrier compound 6-Arm MPEG-Drug Conjugate was designed and synthesized in which benzoic acid was used as model drug. The molecular structure was characterized by means of 1H NMR and 13C NMR spectroscopy. 1H NMR verified that 6-Arm MPEG-Drug Conjugate changed conformation in organic solvent and in aqueous solution. It assembled to nano-sized particle in aqueous solution. So the micelle characteristics of 6-Arm MPEG-Drug Conjugate in water were investigated by fluorescence spectroscopy, dynamic light scattering (DLS) and scanning electron microscopy (SEM). The critical micelle concentration (CMC) was determined by a fluorescence technique to be 2.5×10-2 mg/mL (5.3×10-6 mol/L); The hydrodynamic diameter of micelle was measured to be 67.4 nm at the concentration of 1.0 mg/mL by DLS and the polydispersity index (PDI) was estimated to be 0.106. In addition, 6-Arm MPEG-Drug Conjugate exhibited different aggregation behavior. It was found that tubes and microcubic particles could be formed at the different initial concentration. And it was interested that the aggregates morphological characteristics was changed from tubes to niosomes along with the addition of various contents of water.



Ultrafine Fibrous Membranes by Coaxial Electrospinning for Artificial Blood Vessel

CAO Wen-Xuan, ZHANG Hong, YUAN Xiao-Yan*

2011, 32(6):  1396-1400. 

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Core/shell ultrafine fibers, with dextran (DEX) and poly(ethylene glycol)-b- poly(L-lactide-co-ε-caprolactone) (PELCL) as the core and shell, respectively, were prepared by coaxial electrospinning. Double-layered ultrafine fibrous tubes of the coaxial-electrospun DEX/PELCL fibers were constructed for application as artificial blood vessel by loading vascular endothelial growth factor (VEGF) and platelet derived growth factor-bb (PDGF-bb), respectively in the fiber core. The in vitro releasing results of 4 w indicated that initial burst release occurred for both VEGF and PDGF-bb. The in vivo implantation in abdomen aorta of a rat model showed that the double-layered fibrous tubes loading VEGF and PDGF-bb could be potential used as artificial blood vessels.



Miniemulsion Polymerization by Predissolved Polymer as Costabilizer

YAO Ning-Ning, NI Gang*, ZHAO Wei-Zhen, XU Mei-Ru, DU Juan

2011, 32(6):  1401-1406. 

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A steady miniemulsion copolymer of trifluoroethyl methacrylate(TFMA), n-buty acrylate(BA) and styrene(St) was prepared by using predissolved polymer and hexanediol (HDL) as a costabilizer, AIBN as initiator, SDS/S100/OP as a complex emulsion system. The relationships of polymerization conditions between the final conversion and polymerization stability were discussed in detail. The optimal polymerization condition is 0.7% AIBN, 2% HDL, 0.5% predissolved polymer and m(OP):m(SDS):m(S100) = 2.5:1:0.3. The molecular weight and composition of copolymer were demonstrated by GPC, FT-IR, 1H-NMR, DSC and TGA. The result was showed that HFMA is effectively involved in the copolymerization, the fluorinated acrylate copolymer has a narrower molecular weight distribution. Add a small amount of predissolved polymer can not only improved the emulsion stability but also improved the hydrophobic properties of latex films. After perfluoroalkyl groups were introduced into polymer chains, the wetting-resistance, the water-resistance and the thermal stability of the latex films were evidently enhanced.



Kinetics of Photopolymerization for the Acrylate/Liquid Crystal Mixture

SHI Xiao-Jing, PENG Hai-Yan, LIAO Yong-Gui, XIE Xiao-Lin*

2011, 32(6):  1407-1411. 

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Photo differential scanning calorimetry (P-DSC) was used to characterize the photopolymerization kinetics for the mixture of 2-ethylhexyl acrylate (EHA), trimethylolpropane trimethacrylate (TMPTA) and nematic liquid crystal (P0616A) with 2, 4, 6-trimethylbenzoyldiphenyl phosphine oxide (TPO) as photoiniator at different reaction temperature ranged from -40oC to 80oC. The results revealed that the auto-acceleration of photopolymerization is more obvious than the traditional free radical polymerization, and there are maxima in photopolymerization rate and apparent kinetic constant. The final conversion and the maximum photopolymerization rate increase with the reaction temperature. After the reaction temperature rises to 20oC, the above increases are slight. Rpmax decreases with increasing the content of liquid crystals, and the conversion increases slowly with time. But the final conversions have a slight difference for the acrylate/liquid crystal mixture with different LC content, and all of them close to 80%. With increasing the UV intensity, both of Rpmax and the final conversion increase obviously. The threshold value of UV intensity is 4 mW/cm2. However, Rpmax and the final conversion tend to decrease with increasing the average functionality of monomers.



Preparation and Bio\|Evaluation of Iodine Labelling Gelatin Microspheres and the Coating Microspheres with Sodium Alginate

LUO Dong-Hui, LIU An-Ni, LI Ming-Fang, MA Yu, LI Lin, CHEN Xiao-Li, LIU Li, XIA Chuan-Qin*

2011, 32(6):  1412-1417. 

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This paper describes a method to prepare the gelatin microspheres and the wrapped microspheres with sodium alginate（SA）. The microspheres were labeled with iodine-131,125 by Chloramine-T method and followed by injecting into the liver of rabbits. The characteristic comparisons of the gelatin microspheres and the wrapped microspheres were made and the results indicated that the wrapped microspheres can have a more iodine loading capacity and better stability than the gelatin microspheres. It also appeared that the degradation rate of wrapped microspheres is slower than the gelatin microspheres in physical condition. As a matter of fact the stability of iodine-131 in gelatin microspheres in the rabbits was evidenced by the ECT visualization: no visible radio-speck at the position of thyroid gland has been observed by injecting the wrapped microspheres, while the noticeable radio-speck of thyroid gland has been observed at the same site by injection of the gelatin microspheres, which proved that 131I in wrapped gelatin microsphere has better stability than in the gelatin microspheres.



Structures of AB2 Polymerization Fluids Near Solid Surfaces

SONG Jian-Min*, YAO Ning, ZHU Ling-Xin

2011, 32(6):  1418-1423. 

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Within the framework of the density functional theory (DFT), the free energy function was formulated in terms of the modified fundamental measure theory (MFMT) for hard sphere repulsion and the statistical mechanic theory with the weighted density approximation (WDA) for polymerization. The chemical potential for the AB2 polymerization fluids was established and the expression of the density profiles of the polymerization fluids around a spherical particle was derived. The influence of the reaction conversion, the volume fraction and the spherical particle dimension on density profiles was discussed. Furthermore, the relation of the reaction conversion, the volume fraction and the spherical particle dimension to excess adsorptions was also analyzed in terms of the density profiles.



Influence of Coagulant Temperature on the Membrane Formation Process and Properties of PVDF-g-PNIPAAm Temperature\|sensitive Membranes

FENG Xia, GUO Yan-Fen, ZHAO Yi-Ping, LI Jian-Xin, CHEN Xi, HE Xiao-Ling, CHEN Li*

2011, 32(6):  1424-1430. 

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The copolymer of poly(vinylidene fluoride) grafting poly(N-isopropylacrylamide) (PVDF-g-PNIPAAm) was synthesized and its flat sheet membranes were prepared. The influence of coagulant temperature on membrane formation kinetics was studied by the ultrasonic time-domain reflectometry. Based on the membrane formation kinetics, the influence of coagulant temperature on the structure and performance of PVDF-g-PNIPAAm membrane was studied. The results showed that the coagulant temperature influenced the membrane formation process greatly. The liquid-liquid dimixing dominated the dimixing process at different coagulant temperature. The needed membrane formation time of PVDF-g-PNIPAAm prepared at 30℃ was the longest and that of the membrane prepared at 40℃ was the shortest. The crystal properties of the PVDF-g-PNIPAAm membrane are dominated by the corresponding PVDF structure. The higher the coagulant temperature, the lower the degree of crystallinity is. The NIPAAm content on the surface of PVDF-g-PNIPAAm membrane is much higher than that of the PVDF-g-PNIPAAm copolymer. The NIPAAm content on the surface of PVDF-g-PNIPAAm membrane prepared at 30℃ is the highest. All the membranes presents finger-like pores .The membranes prepared at 30℃ has the largest pores and the highest porosity. The water flux of membrane prepared at 25℃ showed obvious temperature sensitivity and increased intensively at about 30℃.



Promoting Effect of Ethyl Acetate on Anionic Ring-opening Polymerization of l,3,5-Trimethyl-l,3,5-tris(3,3,3-trifluoropropyl)cyclotrisiloxane(D3F)

YANG Peng, GAO Ya-Juan, GUAN Yong, ZHENG An-Na*

2011, 32(6):  1431-1435. 

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Poly[methyl(trifluoropropyl)siloxane](PMTFPS) was prepared in the mixing chamber of a HAAKE torque rheometer using sodium silanolate as the initiator, and ethyl acetate(EA) as the promoter. The promoting effect of EA in the anionic bulk polymerization of D3F was investigated. The results show that the maximum of number average molecular weight(Mn=2.45×105) of PMTFPS was obtained with high yield(89.2%) when the polymerization was carried out in the presence of 2.74%initiator and 0.30 mol/L EA at 120 ℃ for 4.0 min. The backbiting reactions were almost suppressed and 0.74% cyclic by-products were obtained by matrix-assisted laser desorption ionization time-of-flight mass spectrometry(MALDI-TOF-MS) for EA promoter system. Investigations of differential scanning calorimetry(DSC) and thermogravimetic analysis(TGA) show that PMTFPS can be used in a wide range of operational temperatures.



Preparation of Hexanediamine-contained PAMAM Dendrimers Supported on Chitosan Microspheres and Their Application in the Adsorption of Bilirubin

WU Li-Ping, ZHANG Zheng-Pu*, GUO Yi, WANG Yong, LU Wei

2011, 32(6):  1436-1444. 

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Glutaraldehyde cross-linked chitosan microspheres (CS) were prepared by inverse phase suspension reaction. Low generations(Gn≤3)hexanediamine-contained PAMAM dendrimers were supported to chitosan microspheres. Bilirubin adsorption on the above microspheres was carried out in 0.05M phosphate buffer solution (pH=7.2-7.4) at 37℃. The results showed that the equilibrium adsorption percentage of CS-G2.0, CS-G3.0, CS-G1.0, CS-G0 and CS microspheres was 94.61%, 93.44%, 92.97%, 86.47%, 52.38%, respectively. The adsorption percentage of CS-G1.0-3.0 microspheres was over 70% at 0.5h and arrived to the equilibrium at about 1h.The adsorption capacity was up to 42.78mg/g. A ll the moderations (CS-G0-3.0) were much better than CS microspheres for bilirubin adsorption. The effects of temperature, pH, bilirubin initial concentration, ion strength and bovine serum albumin (BSA) on the adsorption properties for bilirubin were studied. It was shown that adsorption percentage increased at higher temperature. Adsorption properties were the best at near neutral solutions of pH≈7. PAMAM dendrimers supported in chitosan microspheres had satisfactory competitive abilities with BSA for bilirubin adsorption though adsorption percentage decreaed to a certain extent in the presence of BSA.