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01 October 2015, Volume 31 Issue 5

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Chemical Research in Chinese Universities Vol.31 No.5 February 2015

2015, 31(5):  0-0. 

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Letter

Synthesis of 2-Hydroxymalononitrile

YANG Jianxin, YIN Yunxing, HE Zhenmin, ZHANG Zhiliu, LIN Xiaojuan, MA Rujian

2015, 31(5):  685-687.  doi:10.1007/s40242-015-5247-3

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Articles

One Step Preparation of Highly Dispersed TiO₂ Nanoparticles

LIU Xu, CHEN Yan, JIAO Shihui, PANG Guangsheng

2015, 31(5):  688-692.  doi:10.1007/s40242-015-5300-2

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A facile approach was developed to prepare highly dispersed TiO₂ nanoparticles with selected phase. The crystallization phase of the nanoparticles can be easily tuned from anatase to rutile by the dosage of hydrochloric acid in the reaction system. The crystallite size of the as-prepared anatase TiO₂ nanoparticles was ca. 3.2 nm with high dispersion. A transparent TiO₂ colloid was obtained by dispersing the as-prepared anatase TiO₂ nanoparticles in deionized water without any organic additives added. The concentration of TiO₂-H₂O colloid can be as high as 1600 g/L. The optical transmittance of TiO₂-H₂O colloid with a low concentration was nearly 100% in the visible region. Furthermore, anatase TiO₂ nanoparticles(TiO₂-NPs) showed superior photocatalytic performance compared to rutile TiO₂-NPs.



Structural Characterization, Vibrational Studies and Electrical Properties of 2-Amino-3-benzyloxy Pyridinium Perchlorate

SAMI Soukrata, MOHAMED Belhouchet, TAHAR Mhiri

2015, 31(5):  693-698.  doi:10.1007/s40242-015-5206-z

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A title organic-inorganic hybrid material 2-amino-3-benzyloxy pyridinium perchlorate was synthesized by slow evaporation at room temperature using 2-amino-3-benzyloxypyridine as the structure-directing agent. The structure of the title compound was determined by means of single-crystal X-ray diffraction at 293 K. The results show that this compound crystallizes in the centrosymetric monoclinic system with a space group of P2₁/n and lattice parameters of a=0.7025(5) nm, b=1.2635(5) nm, c=1.5766(5) nm, Z=4 and V=1.3905(2) nm³. The crystal structure has been determined and refined to R₁=0.0367 and wR₂=0.1022 using 2326 independent reflections and can be described as a succession of organic and inorganic layers parallel to the bc plane. In this arrangement, hydrogen bonds and van der Waals interactions between different species play an important role in the two-dimensional(2D) network cohesion. This compound was also characterized by means of infrared spectroscopy, Raman spectroscopy and thermogravimetric analysis-differential thermal analysis(TG-DTA). Moreover, protonic conduction of this compound determined by an impedance analyzer has been studied in the temperature range of 303-373 K.



Negative Magnetism in Perovskite Manganites Gd_1-xSr_xMnO₃(0.1 ≤x ≤0.3)

ZHANG Yingnan, LI Junjia, ZHANG Ziqing, LIU Fuyang, ZHAO Xudong, LIU Xiaoyang

2015, 31(5):  699-703.  doi:10.1007/s40242-015-5196-x

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A series of Sr-substituted Gd_1-xSr_xMnO₃(0.1≤ x≤ 0.3) materials was prepared via a standard method involving solid-state reaction. Their crystal structure within the entire doping region was determined to be orthorhombic perovskite type. The magnetic properties of the perovskite Gd_1-xSr_xMnO₃(0.1≤ x≤ 0.3) were thoroughly investigated. It appears that Mn ions with high valence state can induce stronger magnetization, and negative magnetization is evident in the manganites with x=0.1 and x=0.2, suggesting that valence fluctuation plays an important role in such systems. The result of XPS analysis indicates that the valence state of Mn ions is 3.25 and there seems to be excess amounts of oxygen in the structure of Gd_0.8Sr_0.2MnO_3+δ. In addition, the results of magnetization measurements demonstrate that spin reversal occurs only when the applied field is less than 1.99×10⁵ A/m, which presumably could be due to the negative exchange interaction between Mn sub-lattice and Gd sites.



Neodymium Complex Obtained from Reductive-coupling of Carbodiimide: Synthesis and Structure of [(Cp")₂Nd(NR)₂C-C(NR)₂Nd(Cp")₂]

ZHENG Bin, ZHANG Xiang, TANG Guodong, ZHANG Lei, PAN Chengling, XU Jiqing, SHENG Shaoding

2015, 31(5):  704-707.  doi:10.1007/s40242-015-5165-4

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A bimetallic oxalamidino complex of neodymium [(Cp")₂Nd(NR)₂C-C(NR')₂Nd(Cp")₂][Cp"=η⁵-C₅H₃-1,3-(SiMe₃)₂, R=C₆H₁₁](2) was obtained via reaction between NdI₂ and carbodiimide[RN=C=NR] (R=C₆H₁₁)(molar ratio 1:1) in tetrahydrofuran(THF) solution, followed by the addition of [KCp"(THF)](1)(molar ratio 1:2) at a low temperature through a reductive-coupling reaction with carbodiimide. The structure of the intermediate product was confirmed by means of elemental analysis, ¹H NMR and ¹³C NMR. Characterization of the product by single crystal X-ray diffraction confirmed the diamidinate type of structure.



Synthesis and Electrochemical Properties of Highly Crystallized CuV₂O₆ Nanowires

HU Fang, LI Malin, WEI Yingjin, DU Fei, CHEN Gang, WANG Chunzhong

2015, 31(5):  708-711.  doi:10.1007/s40242-015-5136-9

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CuV₂O₆ nanowires were prepared via a simple hydrothermal route using NH₄VO₃ and Cu(NO₃)₂ as starting materials. The structures and electrochemical properties of CuV₂O₆ nanowires were characterized by means of X-ray diffraction(XRD), scanning electron microscopy(SEM) and transmission electron microscopy(TEM). The results show that the CuV₂O₆ nanowires are about 100 nm in width and single crystalline grown along [001] direction. CuV₂O₆ nanowires delivered a high initial discharge capacity of 435 and 351 mA·h/g at current densities of 50 and 100 mA·h/g, respectively. The electrochemical kinetics of the CuV₂O₆ nanowires was also investigated by means of electrochemical impedance spectroscopy(EIS) and the poor rate performance was observed, which may be attributed to the low ion diffusion coefficient of the CuV₂O₆ nanowires.



Synthesis, Structures and Properties of Three New Compounds Based on Multidentate Ligand Containing Triazole and Pyrimidine

LÜ Lei, MU Bao, LI Na, HUANG Rudan

2015, 31(5):  712-718.  doi:10.1007/s40242-015-5051-0

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Three new compounds, namely, [Zn(mtpo)₂(H₂O)4](1), [Cd(mtpo)₂·CH₃CH₂OH]_n(2) and [Mn(mtpo)₂·CH₃CH₂OH]_n(3)(Hmtpo=4,7-dihydro-5-methyl-7-oxo-[1,2,4]triazolo[1,5-a]pyrimidine), have been synthesized via hydrothermal or solvothermal methods and characterized by means of elemental analyses, Fourier transform infrared(FTIR) spectroscopy, powder X-ray diffraction(PXRD), thermogravimetric analysis(TGA) and single-crystal X-ray diffraction. The results obtained from the single-crystal X-ray diffraction indicate that compound 1 has a mononuclear structure, and crystallizes in a monoclinic crystal system with P2₁/c space group, which exhibits a 2D supramolecular network constructed by hydrogen bonds and π-π interactions. Compounds 2 and 3 are isomorphous and crystallize in a tetragonal system with space group of I4₁/a. The M²⁺(M=Cd, Mn) ions in compounds 2 and 3 have the octahedral coordination geometry. Hmtpo acts as a bridging ligand linking the metal ions to form an infinite 3D framework with 4-connected {4²·8⁴} topology. There are hydrogen bonds between the guest ethanol molecules and the mtpoligands, which make the ethanol molecules exist in a 3D framework. In addition, luminescent properties of compounds 1 and 2 as well as magnetic property of compound 3 were investigated and water vapor adsorption and nitrogen sorption for compounds 2 and 3 were researched at 298 and 77 K, respectively.



Rational Fabrication of Size Tunable SnO₂ Hollow Microspheres

HUANG Zhiqiang, GUO Jia, WANG Xiaoling, GAO Haiyan, YU Jianguo, ZHAO Yongnan, LI Guodong

2015, 31(5):  719-723.  doi:10.1007/s40242-015-4452-4

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A designed solution route was developed to fabricate size tunable SnO₂ hollow microspheres based on the sol-gel theory. The hydrolysis of SnSO₄ released protons to form SnO₂ particulates and induced the decrease of pH value. To minimize the high surface energy, the SnO₂ particulates tended to assemble into large particles, the size of which was affected by the electrolyte concentration or pH value. Elevating SnSO₄ content aroused the decrease of the pH value that directed to the shrinkage of the aggregated particle size of SnO₂. Size tunable SnO₂ hollow microspheres were then rationally fabricated under solvothermal conditions via Ostwald ripening by simply adjusting the SnSO₄ concentration. The in situ pH decrease directed to the shrinkage of the particle size from 270 nm to 112 nm. The formation mechanism was confirmed and rationally elucidated by the time dependant morphology evolution. Charge-discharge tests revealed that the reduced particle size aroused an improved lithium ion battery performance.



A Highly Selective and Sensitive Ratiometric Fluorescent Probe for pH Measurement Based on Fluorescence Resonance Energy Transfer

LIANG Fanghui, WANG Di, MA Pinyi, WANG Xinghua, SONG Daqian, YU Yong

2015, 31(5):  724-729.  doi:10.1007/s40242-015-5124-0

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Fluorescein-rhodamine 6G(Flu-Rh) was synthesized and used as the fluorescence probe for pH measurement based on fluorescence resonance energy transfer(FRET). In the probe, fluorescein fluorophore and pH-sensitive rhodamine 6G hydrazide were used as FRET donor and acceptor, respectively. The values of acidity constant(pK_a) and fluorescence quantum yield(Φ) of Flu-Rh were 3.71 and 0.72, respectively. The fluorescence efficiency of Flu-Rh remains almost constant when the pH value of the sample solution changed 10 times in a range of 4.78-7.03 continuously. The present probe is simple and easy-to-use for the pH measurement in acidic media.



Ionic Liquid as a Precursor to Synthesize Nitrogen- and Sulfur-co-doped Carbon Dots for Detection of Copper(II) Ions

XU Panpan, WANG Chunfeng, SUN Dong, CHEN Yujuan, ZHUO Kelei

2015, 31(5):  730-735.  doi:10.1007/s40242-015-5118-y

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A facile approach was reported for the synthesis of nitrogen- and sulfur-co-doped carbon dots(N/S-CDs) by the sulfuric acid carbonization of 1-butyl-3-methylimidazolium 2-amino-3-mercaptopropionic acid(L-cysteine) salt([C₄mim][Cys]) ionic liquid. The as-prepared N/S-CDs exhibited a good solubility, excitation-dependent emission behavior, and high resistance to photobleaching. Furthermore, the N/S-CDs were employed as a fluorescent probe for detecting Cu²⁺ in real water samples with satisfactory recovery.



Reactivity of Organolithium Reagents to 2,3,4,5-Tetraphenylcyclopentadienone and Crystal Structures of Addition Products

ZHANG Xiaoyong, HAN Limin, ZHU Ning, GAO Yuanyuan, SUO Quanling

2015, 31(5):  736-741.  doi:10.1007/s40242-015-5219-7

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The conjugate addition reactions of four organolithium reagents to 2,3,4,5-tetraphenylcyclopentadienone (tetracyclone) were investigated to reveal the reactivity of organolithium reagents to tetracyclone. The results show that 1,2-addition products 2,3,4,5-tetraphenyl-1-(2-thienyl)-2,4-cyclopentadien-1-ol(1), 1-n-butyl-2,3,4,5-tetraphenyl-2,4-cyclopentadien-1-ol(2) and 1,2,3,4,5-pentaphenyl-2,4-cyclopentadien-1-ol(3) were synthesized in excellent yields while tetracyclone reacted with 2-thienyllithium, n-butyllithium and phenyllithium, respectively. Interestingly, three 1,2-, 1,4- and 1,6-addition isomers 1-tert-butyl-2,3,4,5-tetraphenyl-2,4-cyclopentadien-1-ol(4), 4-tert-butyl-2,3,4,5-tetraphenyl-2-cyclopenten-l-one(5) and 2-tert-butyl-2,3,4,5-tetraphenyl-3-cyclopenten-l-one(6), were simultaneously obtained by the conjugate addition reaction of tert-butyllithium with larger steric hindrance to tetracyclone. Compounds 1-6 were characterized by ¹H and ¹³C NMR spectra, Fourier transform infrared(FTIR) spectra and mass spectra(MS). The crystal and molecular structures of compounds 1, 2 and isomers 5, 6 were determined by X-ray single crystal diffraction technique. The results imply that the steric hindrance of tert-butyllithium probably play a key role in controlling the conjugate addition reaction. The conjugate addition mechanism of organolithium reagents to tetracyclone was proposed.



Design, Synthesis and Activities of Aziridine Derivatives of N⁵-Methyltetrahydrofolate Against Methionine Synthase

DENG Xiling, GUO Ying, TIAN Chao, LIU Junyi, WANG Xiaowei, ZHANG Zhili

2015, 31(5):  742-745.  doi:10.1007/s40242-015-5194-z

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Aziridine derivatives of N⁵-methyltetrahydrofolate were designed and synthesized based on the mechanism of methionine synthase, and their biological activities were investigated as well. The aziridine derivatives 1 and 6 exhibited superior inhibitory activities(IC₅₀: 5.05 and 4.15 μmol/L, respectively) compared to the corresponding chain analogue 4(IC₅₀=24.42 μmol/L). The results suggest that the aziridine derivatives can get potential activities against nucleophilic methionine synthase.



Design, Synthesis and Pharmacological Evaluation of Novel 4-Phenoxyquinoline Derivatives as Potential Antitumor Agents

HU Hao, JIANG Mingyan, XIE Lijun, HU Gang, ZHANG Cuirong, ZHANG Lixia, ZHOU Shunguang, ZHANG Meihui, GONG Ping

2015, 31(5):  746-755.  doi:10.1007/s40242-015-5166-3

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A series of novel 4-phenoxyquinoline derivatives containing 3-amino-2-cyano-acrylamide framework was designed and synthesized, and the in vitro cytotoxic activities of them against five cancer cell lines(HT-29, H460, A549, MKN-45, and U87MG) were evaluated. Most of the compounds exhibited moderate-to-significant cytotoxicity and high selectivity against one or more cell lines as compared with Foretinib. The studies of their preliminary structure-activity relationships(SARs) indicate that the compounds containing methyl groups, especially methyl groups at 4-position of the phenyl ring(moiety B) are more effective. Among them, compound 36 shows the most potent antitumor activities with IC₅₀ values of 0.04, 0.09, 0.67, 0.39 and 1.10 μmol/L against HT-29, H460, A549, MKN-45 and U87MG cell lines, respectively.



Synthesis of Novel Tartaric Acid-derived Chiral Phosphite Ligands and Their Application in the Cu-catalyzed Conjugate Addition of Diethylzinc to Cyclic Enones

PANG Zengbo, XING Aiping, WANG Lailai

2015, 31(5):  756-760.  doi:10.1007/s40242-015-5142-y

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Five novel tropos (3R,4R)- and/or (3S,4S)-N-benzyltartarimide-derived biphenylphosphite ligands were synthesized and applied in the Cu-catalyzed asymmetric conjugate addition of diethylzinc to cyclic enones with up to 75% e.e. Compared with the reported ligand 1-N-benzylpyrrolidine-3,4-bis[(R)-1,1'-binaphthyl-2,2'-diyl]phosphite-L-tartaric acid, the issue that L-(+)-tartaric acid backbone and (R)-binaphthyl showed strong matched/mismatched character was solved with these tropos ligands. It was found that the enantioselectivity was mainly controlled by the absolute configuration of N-benzyltartarimide backbone, and both enantiomers of the addition products can be obtained by simply changing the configuration of N-benzyltartarimide substituent.



A Green and Efficient Trinitration System for Aromatic Compounds with Bi(NO₃)₃·5H₂O/[HMIM]ClO₄ as Catalyst in HNO₃/Ac₂O

SUN Weizhi, YU Shitao, XIAN Mo

2015, 31(5):  761-765.  doi:10.1007/s40242-015-5087-1

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To investigate the green trinitration method of aromatic compounds, with Lewis acid/ionic liquid as catalyst and HNO₃/Ac₂O as nitration reagent, a Lewis acid/ionic liquid/HNO₃/Ac₂O system was established. In various combinations of Lewis acids and ionic liquids, Bi(NO₃)₃·5H₂O/[HMIM]ClO₄ proved to be a very efficient catalyst for the trinitration of activated aromatic compounds and reusable for 3 times. Reaction conditions for the trinitration were optimized and yields of the trinitro products were from mild to excellent. This sulfuric acid-free system has the advantages of strong trinitration ability, low environment pollution, low toxicity, low cost and high potential for industrial application.



Design, Synthesis and Antitumor Activity of Novel 6,7-Dimethoxyquinazoline Derivatives Containing Diaryl Urea Moiety

HOU Yunlei, WU Shasha, MA Longsheng, BAI Jinying, LIU Zijian, ZHAO Yanfang

2015, 31(5):  766-773.  doi:10.1007/s40242-015-5036-z

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A series of 6,7-dimethoxyquinazoline derivatives connected by diaryl urea scaffolds was designed, synthesized and their in vitro antitumor activities were evaluated. Most of them showed an excellent potency against the four tested cancer cell lines as compared with sorafenib. Particularly, a promising compound 20 was identified, which showed the most potent antitumor activities with IC₅₀ values of 0.08, 0.09, 0.16 and 0.19 μmol/L against H460, HT-29, MKN-45 and MDA-MB-231 cell lines, respectively. The structure-activity relationship(SAR) analysis indicated that compounds with dimethylamino or diethylamino group at the C4 position of 6,7-dimethoxyquinazoline moiety exhibited superior activities than compounds bearing morpholino groups.



Gene Cloning and Molecular Characterization of a β-Glucosidase from Thermotoga Naphthophila RUK-10: an Effective Tool for Synthesis of Galacto-oligosaccharide and Alkyl Galactopyranosides

KONG Fansi, YANG Jingwen, ZHEN Zhen, LIANG Tingting, ZHU Dongliang, GAO Renjun, XIE Guiqiu

2015, 31(5):  774-780.  doi:10.1007/s40242-015-5179-y

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A novel thermostable β-glucosidase(Tnap0602) with β-galactosidase activity was cloned from Thermotoga naphthophila RUK-10 and overexpressed in Escherichia coli BL21(DE3) with the aid of pET28b(+) vector. The recombinant β-glucosidase was purified to homogeneity by heat precipitation and Ni²⁺-affinity chromatography. The molecular weight of the recombinant enzyme was estimated to be 51 kDa by SDS-PAGE analysis. The optimum temperature for the hydrolyses of p-nitrophenyl-β-D-glucopyranoside and o-nitrophenyl-β-D-galactopyranoside by the recombinant β-glucosidase were both above 95℃, and the corresponding optimum pH value was found to be the same as 7.0. Thermostability studies show that the half-lives of the recombinant enzyme at 75, 80, 85 and 90℃ are respectively 84, 32, 14, and 3 h, and it is quite stable in a pH range of 5.0-10.0. The K_m and V_max values of the recombinant β-glucosidase for the hydrolysis of pNPGlu at 80℃ are 0.127 mmol/L and 18389.1 μmol·min^-1·mg^-1, the corresponding values are 0.625 mmol/L and 6250 μmol·min^-1·mg^-1 for the hydrolysis of oNPGal, respectively. The enzyme also display the hydrolysis activity for lactose and cellobiose. Galacto-oligosaccharide and alkyl galactopyranosides could be synthesized from Tnap0602 when lactose was used as the transglycosylation substrate, indicating that the thermostable β-glucosidase could be a candidate for industrial application.



A Visualized Fusion Protein Based on Self-assembly Hydrophobin HGFI

ZHAO Liqiang, LIU Jinyuan, SONG Dongmin, WANG Xiangxiang, TAI Feifei, XU Haijin, QIAO Mingqiang

2015, 31(5):  781-786.  doi:10.1007/s40242-015-5135-x

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Hydrophobins are a type of small amphipathic proteins with a unique self-assembly property, which can be used to modify material surfaces and adsorb enzymes, antibodies and even cells. In this study, a fusion protein consisting of hydrophobin HGFI and green fluorescent protein(GFP) was successfully obtained from Pichia patoris (P. pastoris). Water contact angle(WCA) measurement proves that the wettability of the surfaces of different materials was changed. We further demonstrated the self-assembly ability of HGFI-GFP, which can be used to disperse the multi-walled carbon nanotubes(MWCNTs). Finally, the adsorption of HGFI-GFP onto the surface of the tissue engineering material poly(ε-caprolactone)(PCL) was evaluated by detecting the fluorescence of the fusion protein itself. The resalt demonstrates that both the basic self-assembly activity of the HGFI domain and the functional activity of the GFP domain were still remained.



Highly Selective Gas-phase Synthesis of 1,1-Dichloroethylene from 1,1,2-Trichloroethane over Supported Amine Catalysts

TANG Cen, JIN Yanxia, WANG Xiaoxia, HU Gengshen, XIE Guanqun, LI Xiaonian, LUO Mengfei

2015, 31(5):  787-791.  doi:10.1007/s40242-015-5172-5

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The manufacture of 1,1-dichloroethylene(1,1-DCE) usually employs liquid phase method to perform the dehydrochlorination of 1,1,2-trichloroethane(TCE), where large amounts of high-concentration salty wastewater is produced inevitably. It has been a long-term goal to achieve the gas phase synthesis of 1,1-DCE via supported catalysts. In this work, the gas-phase synthesis of 1,1-DCE from TCE was studied in the presence of pentaethylenehexamine(PEHA) supported on silica. High and stable selectivity to 1,1-DCE(up to 98%) was obtained, which could be ascribed to the relatively strong basicity of PEHA according to a proposed E2 mechanism. The formation of PEHA chloride from the HCl generated in situ was detected and was considered to be the main reason for the deactivation of PEHA catalyst.



Pyrrol-2-yl-methanone Modified Silica as Electron Acceptor for the Oxidation of Water Catalyzed by Cobalt(II) Complexes

YU Hailing, HONG Bo, ZHAO Hongyan

2015, 31(5):  792-796.  doi:10.1007/s40242-015-5168-1

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To develop a new type of non-oxidant electron acceptors for water oxidation, 3-(methyl)phenyl-(3,5-dimethyl-1H-pyrrol-2-yl)methanone modified silica(SiO₂@py) was synthesized and used as host to Co₄O₄ cubane forming nanoparticles(SiO₂@pyCo₄). In the presence of Ru(bpy)₃²⁺ and under the irradiation of white LED(light emitting diode) light(10 W), SiO₂@pyCo₄ can catalyze water oxidation without extra electron acceptor(e.g., Na₂S₂O₈). Moreover, the turnover frequency(TOF) value of SiO₂@pyCo₄ is larger than that of Co₄O₄ cubane under the same conditions, and the longer lasting time of SiO₂@pyCo₄ indicates that SiO₂@py can enhance the stability of Co₄O₄ in water. Our results provide an economic route to develop dioxygen evolution systems based on the assembly of organic electron acceptor modified silica with active cobalt complexes.



Pyrrol-2-yl-methanone Modified Silica as Electron Acceptor for the Oxidation of Water Catalyzed by Cobalt(II) Complexes

WU Yi, WANG Li, CHEN Qiuyun

2015, 31(5):  797-800.  doi:10.1007/s40242-015-5156-5

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To develop a new type of non-oxidant electron acceptors for water oxidation, 3-(methyl)phenyl-(3,5-dimethyl-1H-pyrrol-2-yl)methanone modified silica(SiO₂@py) was synthesized and used as host to Co₄O₄ cubane forming nanoparticles(SiO₂@pyCo₄). In the presence of Ru(bpy)₃²⁺ and under the irradiation of white LED(light emitting diode) light(10 W), SiO₂@pyCo₄ can catalyze water oxidation without extra electron acceptor(e.g., Na₂S₂O₈). Moreover, the turnover frequency(TOF) value of SiO₂@pyCo₄ is larger than that of Co₄O₄ cubane under the same conditions, and the longer lasting time of SiO₂@pyCo₄ indicates that SiO₂@py can enhance the stability of Co₄O₄ in water. Our results provide an economic route to develop dioxygen evolution systems based on the assembly of organic electron acceptor modified silica with active cobalt complexes.



Dipyrrin-based Complexes for Solution-processed Organic Solar Cells

ZOU Liyun, GUAN Shuang, LI Leijiao, ZHAO Li

2015, 31(5):  801-808.  doi:10.1007/s40242-015-5140-0

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Three dipyrrin-containing metal complexes and a boron dipyrromethene(BODIPY)-containing complex were designed and synthesized. The photophysical properties, electrochemical behaviours and photovoltaic performance were extensively investigated. Density functional theory calculations were also performed on those complexes. These complexes, together with electron-acceptor [6,6]-phenyl-C71-butyric acid methyl ester, were utilized for the fabrication of solution-processed bulk heterojunction solar cells as the electron-donor materials. The more efficient electron acceptor BODIPY segment renders a lower energy gap and a relatively better photovoltaic conversion efficiency of 0.58%. These results prove that BODIPY segment has a great potential for constructing efficient organic solar cell materials.



Influence of Extraction Barrier on the Loss Process of Photogenerated Charge Carrier in Polymer Bulk Heterojunction Solar Cells

LIU Bo, XU Feng, ZHANG Xinghua, YAN Dadong, LU Dan

2015, 31(5):  809-813.  doi:10.1007/s40242-015-5102-6

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Based on a full device model adopting three-dimensional Pauli master equation approach, the charge carrier loss process due to poor extraction channels between electrode and active layer in polymer bulk heterojunction(BHJ) solar cells was studied. The influence of barrier height on device performance was simulated to reveal the importance of electrode improvement. It was found that relatively large extraction barrier height(over 0.40 eV) can lead to the significant diminishing of the overall charge collection efficiency, since bimolecular recombination rate would increase to a high level due to enhanced space charge accumulation effect near electrodes. In contrast, the percentage of charge carrier annihilated due to geminate recombination did not change significantly with barrier height variation. Our simulation results may provide the basis for a more accurate model and potential direction of polymer BHJ solar cells improvement.



Stability of Pyrotechnic Composition in Flame Detonator Exposed to Severe Thermal Stimulus

CHENG Jun, YAN Nan, YE Yaokun, ZHENG Fei

2015, 31(5):  814-819.  doi:10.1007/s40242-015-5083-5

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The stability of pyrotechnic composition used in flame detonator was studied at severe temperatures (-70-130℃) for 5 d. For single N-LTNR(normal lead styphnate), camera was used to observe the shape and colour of N-LTNR in the DSC(differential scanning calorimetry) furnace during continuous heating and cooling processes. Based on the DSC-TGA(thermogravimetric analysis) results, it can be seen that when the temperature exceeded 110℃, N-LTNR lost its crystal water, making the energetic material become darker in colour, smaller in dimension, lager in volume and lighter in weight(3.416%); when the temperature was below -40℃, the phenomenon of sample broking, jumping and cracking happened. For the N-LTNR and Pb(N₃)₂(lead azide) double layers, the loss of N-LTNR's crystal water at the temperature higher than 110℃ caused the hydrolysis reaction of Pb(N₃)₂, and the purity of Pb(N₃)₂ measured after the temperature cycling decreased from 98.6% to 95.26%. For the flame detonator, the height and diameter of the flame detonator were measured and no apparent changes of them were found. The p-t(pressure-time) test shows that the peak pressure was decreased by 3.9%. Therefore, the operating temperature of this flame detonator should be limited to -40-110℃.



Synthesis of LiMn₂O₄ Nano-wires via Flux Method and Their Usage as Cathode Material for Lithium Ion Batteries

MENG Yujia, LIU Xiaoyang, LIU Li, LI Benxian, ZHAO Xudong, FENG Likun, WANG Yanxiang, WANG Xiaofeng

2015, 31(5):  820-824.  doi:10.1007/s40242-015-5077-3

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LiMn₂O₄ nano-wires with ideal size distribution were readily synthesized by flux method. Samples prepared conventionally were used as the comparison references to investigate the effect of flux. The structural, morphological and electrochemical properties of nano-sized materials were examined by powder X-ray diffraction(XRD) analysis, scanning electron microscopy(SEM) and charge-discharge cycling analysis. Results from galvanostatic charge-discharge analysis show that the samples prepared at 700℃ via flux method(FM-700) afford the highest initial discharge capacity of 125.5 mA·h/g between 3.0 to 4.3 V at a rate of 0.2 C. After 50 cycles, a cycling retention of 89.6% is evident. Overall, the LiMn₂O₄ nano-wires developed in this work seem to be promising cathode materials for lithium ion batteries suitable to different energy-saving settings.



First-principles Study on the Electronic and Bonding Properties of PbTiO₃ (110) Polar Terminations

ZHANG Guoxu, YU Haitao, XIE Ying

2015, 31(5):  825-829.  doi:10.1007/s40242-015-5074-6

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The electronic structures and bonding properties of the (110) polar terminations of cubic PbTiO₃ were examined by the first-principles calculations at the generalized gradient approximation level. Two stoichiometric (PbTiO and O₂) and three nonstoichiometric(TiO, Pb, and O) terminations were considered in this study. With the aid of the calculated electron density differences, atomic charges, band structures, and densities of states, the charge redistributions and electronic properties were evaluated in detail. Furthermore, based on the calculated results of the cleavage energies, relaxation energies, and surface energies of the investigated terminations, the charge compensation by the modification of the surface stoichiometry and the fillings of surface states were thermodynamically evaluated.



Optical Properties of Dye Based on Hydroxamate Improved with Designed Tridentate Ligands for Dye Sensitized Solar Cell: a Theoretical Study

XIE Mo, CHEN Jie, WANG Jian, ZHANG Hongxing

2015, 31(5):  830-834.  doi:10.1007/s40242-015-5073-7

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A density function theory(DFT) study was made on three dyes based on hydroxamate with different ligands[terpyridine, isothiocyanate(NCS) and 2,2'-bis(thienyl)-tripyrrinate(2-BTTP)] to investigtate their device performance optimization in dye sensitized solar cell(DSSC). Based on the adsorbed dye on TiO₂ (101) surface, the ground state geometry structures, electronic structures, absorption spectra and correspongding charge transfer properties were analysed in detail. The results indicate that the ligand replacement of terpyridine by NCS and 2-BTTP improves the low-energy region absorption of hydroxamate based dyes significantly. The electron injection and light harvesting capability of hydroxamate based dyes are enhanced by NCS and 2-BTTP ligands as well. In the visible region, hydroxamate based dyes have the potentials to become panchromatic light absorbers according to our research.



Immobilization of Transition-metal Hydroxamates on Polystyrene Resins: Effective Biomimetic Heterogeneous Catalysts for Aerobic Oxidation of Ethylbenzene

WANG Ruixin, WANG Hongjing, WANG Xiaogang, LEI Caiping, SHI Xiaohui

2015, 31(5):  835-840.  doi:10.1007/s40242-015-5072-8

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Salicylhydroxamic acid(SHA) was covalently grafted onto chloromethylated crosslinked polystyrene spheres(CMCPS) by the Friedel-Crafts alkylation reaction. The amount of SHA on CPS was found to be mainly dependent on the amount of Lewis acid(SnCl₄) used and the reaction temperature. Under optimized conditions, the amount of SHA attached to CPS could reach up to 0.43 g/g CPS. Transition metal ions[Co(II), Cu(II), Fe(III) or Mn(II)] were then introduced into the resulting SHA-functionalized microspheres(SHA/CPS) through SHA-metal ion chelation. The obtained microspheres MSHA/CPS were explored as biomimetic catalysts for the aerobic oxidation of ethylbenzene(EB) to ethylbenzene hydroperoxide(EBHP). Among the four supported metal catalysts, FeSHA/CPS showed the highest catalytic activity and good reusability, indicating its great potential as an effective heterogeneous catalyst for the aerobic oxidation of hydrocarbons under mild conditions.



Hierarchical TiO₂ Flower-spheres with Large Surface Area and High Scattering Ability: an Excellent Candidate for High Efficiency Dye Sensitized Solar Cells

MA Jian, YAO Shiting, CHENG Pengfei, DU Sisi, SUN Yanfeng, LIU Fengmin, LU Geyu

2015, 31(5):  841-845.  doi:10.1007/s40242-015-5037-y

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Hierarchical TiO₂ flower-spheres assembled from porous nanosheets-stacked of nanoparticles were synthesized by a simple hydrothermal method with one-step. The as-prepared TiO₂ flower-spheres showed a diameter range from 200 nm to 550 nm and a large surface area of 188 m²/g. A double layer photoanode made of P25 nanoparticles and as-prepared TiO₂ flower-spheres was fabricated for the dye sensitized solar cells(DSSCs). The efficient light scattering and dye absorption of the photoanode can be attributed to the top-layer of hierarchical TiO₂ flower-spheres. DSSCs based on the double layers photoanode exhibit a higher energy conversion efficiency of 8.11% with a short-circuit photocurrent density of 17.87 mA/cm², indicating that there is an increase of 38% in the conversion efficiency compared to those based on electrode P25(5.91%, 14.09 mA/cm²).



Template Synthesis and Characterization of Cu₂O/TiO₂ Coaxial Nanocable for Photocatalysis

WANG Hongzhi, LIU Ning, LU Jing, YAO Suwei, JIANG Shisheng, ZHANG Weiguo

2015, 31(5):  846-850.  doi:10.1007/s40242-015-5019-0

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Coaxial nanocable consisted of p-type Cu₂O nanowires and n-type TiO₂ nanotubes arrays was prepared in the porous anodic aluminum oxide(AAO) template via the sol-gel method and subsequent electrodeposition method. X-ray diffraction analysis identified an anatase structure of the TiO₂ nanotubes and cubic structure of the Cu₂O nanowires. The obtained samples were also characterized by scanning electron microscopy(SEM), transmission electron microscopy(TEM) and energy dispersive X-ray spectroscopy(EDS). The diffrence of open circuit potential of the coaxial nanocable electrode was larger than that of the TiO₂ nanotubes electrode under ultraviolet illumination, which means doping with Cu₂O could improve the photovoltage effectively. Meanwhile, nanocable arrays exhibited a high activity for photodegrading Rhodamine B under Xe lamp irradiation and the photocatalysis degradation efficiency was up to 98.69% after degradation for 7 h. The enhanced photocatalytic activity could be attributed to the high migration efficiency of photoinduced electrons, which may suppress the charge recombination effectively.



Hydroformylation of 1-Octene over Nanotubular TiO₂-supported Amorphous Co-B Catalysts

SHI Yukun, HU Xiaojing, ZHU Baolin, ZHANG Shoumin, HUANG Weiping

2015, 31(5):  851-857.  doi:10.1007/s40242-015-5002-9

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TiO₂ nanotubes supported amorphous Co-B(Co-B/TNTs) catalyst was prepared via impregnationchemical reduction procedure. The catalyst was characterized with transmission electron microscopy(TEM), ammonia temperature-programmed desorption(NH₃-TPD), thermogravimetry-differential thermal analysis(TG-DTA), Fourier transform infrared spectroscopy(FTIR) and Raman spectroscopy. The effects of temperature and ratio of CO to H₂ on the hydroformylation of 1-octene were studied. At an optimized reaction temperature(150℃) and volume ratio of CO to H₂(2:1), the conversion of 1-octene can reach 97.4% with a selectivity of 23.1% for total aldehydes and n/i-aldehyde molar ratio of 40:60. To obtain higher selectivity for linear aldehydes, Co-B/TNTs modified with triphenylphosphine for the hydroformylation of 1-octene were investigated. When molar ratio of P/Co was 4, the yield of total aldehydes was the highest(31.6%) with a good selectivity for linear product(n/i-aldehyde molar ratio was 70:30). In recycle use, the Co-B/TNTs catalyst modified with triphenylphosphine could be reused five times without reducing the activity and selectivity obviously. For a comparative study, all the Co-B/TNTs to catalyze the hydroformylation of other olefins exhibited high conversion under the optimized conditions.



Transport Properties of Alkali Fluoride High Temperature Ionic Liquids and Application of Theories of Viscous Flow

POPESCU Anamaria, CONSTANTIN Virgil

2015, 31(5):  858-864.  doi:10.1007/s40242-015-4467-x

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The transport properties of several alkali fluoride high temperature ionic liquids(LiF, NaF, KF, RbF and CsF) were studied in a range of 980-1400 K and the temperature dependences of the viscosity and density were interpreted, in agreement with the classical equations characterizing the viscous flow(Arrhenius, Batchinski, Eyring and Frenkel). The experimental results reveal the validity of these equations even at high temperatures, suggesting that no significant structural changes of alkali fluorides occurred in the studied temperature range. Our results clearly demonstrate that the mentioned thermo-physical properties can be used as powerful tools in the further investigations of the ionic interactions governing the alkali fluoride molten salts.



Impact of Alkoxyl Tail of Fullerene Dyad Acceptor on Crystalline Microstructure for Efficient External Treatment-free Polymer Solar Cells with Poly(3-hexylthiophene) as Donor

XUE Rongming, ZHAO Yue, XU Guiying, LI Yaowen, LI Yongfang

2015, 31(5):  865-872.  doi:10.1007/s40242-015-5184-1

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A series of tri(alkoxyl)benzene-fullerene dyads(PCBB-Cn, n=4, 6, 8, 10, 12) with varied tri(alkoxyl) chain lengths was designed, synthesized and used as acceptor materials in polymer solar cells(PSCs). The five fullerene dyads possess similar absorption spectra in dilute solution, decreased glass-transition temperature(T_g) and gradually elevated lowest unoccupied molecular orbital(LUMO) energy levels from -3.87 eV to -3.73 eV with the increase of the alkoxy chain length. In the fabrication of PSCs with poly(3-hexylthiophene)(P3HT) as donor and the fullerene dyads as acceptor, PCBB-Cn with longer tri(alkoxyl) chains and lower T_g can induce crystalline structure of P3HT during spin-coating the photoactive layer at room temperature and form nanoscale phase separated interpenetrating network of P3HT:PCBB-Cn blend films, which results in the improvement of photovoltaic performance of PSCs. A power conversion efficiency of 3.03% for the PSCs based on P3HT:PCBB-C10 was obtained without thermal annealing or solvent annealing. The thermal and solvent annealing-free fabrication using the fullerene dyads as acceptor is very important for the roll to roll production of PSCs with flexible large area.



Study on Refined Triticale Straw Reinforced PP Composites

YANG Dalei, HU Wei

2015, 31(5):  873-877.  doi:10.1007/s40242-015-5145-8

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Triticale straw(TS) and refined triticale straw(RTS) were characterized by scanning electron microscope(SEM), Fourier transform infrared spectroscopy(FTIR) and thermogravimetric analysis(TGA) in detail, and their application in polypropylene(PP) composite was explored. RTS was obtained by refining TS with environmentally benign processes, by which hemicelluloses and lignin were effectively removed. This was proved by FTIR analysis. The effect of cellulose content on the composite thermal stability and mechanical properties was also examined. RTS has better thermal stability than TS because RTS has lower flammable noncellulose ratio. T_5%(temperature with mass loss of 5%) of RTS could be more than 200℃. It is high enough to meet the requests of processing most polyolefin composites. Both TS and RTS acted as nucleating agents in PP crystallization process. TS was proved to be a filler of the composite, and RTS to be a reinforcing material for the composite. The flexural strength and modulus of RTS/PP increased about by 5% and more than 100%, respectively, compared with those of PP, when the mass fraction of RTS and compatibilizer were 30% and 2%, respectively. The thermal stability of RTS/PP composites was also better than that of TS/PP composites.



Aggregation of Glycerol Induced by Carbon Nanotubes in Aqueous Solution and Its Influencing Factors

LIU Linlin, ZHAO Dongxia, YANG Zhongzhi

2015, 31(5):  878-884.  doi:10.1007/s40242-015-5138-7

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Carbon nanotubes(CNTs) have received wide application and investigation because of their unique electronic, chemical and mechanical properties. But the self-aggregation of CNTs limits their practical application and study. In order to disperse CNTs effectively, polymers, such as polyglycerol and its derivatives, are adopted as dispersants in view of their strong interaction with CNTs. In order to understand the interaction between CNTs and glycerol in water in detail, a series of simulations has been conducted to investigate the interaction between them and analyze the influences of CNTs diameter and temperature. All the analyses indicate that the glycerol molecules are prone to aggregate around CNTs with the addition of CNTs. This is mainly due to hydrophobic interaction. It is confirmed that this aggregation is influenced by CNTs diameter and the temperature to some degree. This work will establish the basis for the exploration of polyglycerol and its derivatives interacting with CNTs and provide an invaluable guide to seek for emergent dispersants for CNTs.



Synthesis of NiFe₂O₄ Nanowires with NiO Nanosheet as Precursor via a Topochemical Solid State Method

FENG Jing, HOU Xiangyu, CHEN Tingting, LIU Shengna, FAN Zhuangjun, REN Yueming, LÜ Yanzhuo

2015, 31(5):  885-889.  doi:10.1007/s40242-015-5132-0

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Large scale NiFe₂O₄ nanowires were synthesized with NiO nanosheets as precursor by means of the topochemical solid state method. The morphologies and magnetic properties of NiFe₂O₄ annealed at different temperatures were studied. An appropriate annealing temperature was requested to transfer NiO nanosheets and Fe^- ions into NiFe₂O₄ nanowires. In the beginning stage of synthesizing process, the shape of NiO nanosheets remained unchanged at low temperatures. And then, NiO nanosheets split into nanowires from 400℃ to 600℃. At last they transformed into nanoparticles from 700℃ to 1000℃. Thus, the optimized annealing temperature was selected as 600℃ because the NiFe₂O₄ obtained at 600℃(N600) exhibited a maximum aspect ratio of 50 with a diameter of 20 nm and a length of 1 μm. Furthermore, N600 also displayed the largest magnetization value of 26.86 A·m²/kg and the lowest coercivity(H_c) of 8914 A/m.



Disulfide-crosslinked Poly(L-glutamic acid) Grafted Mesoporous Silica Nanoparticles and Their Potential Application in Drug Delivery

WU Huiyong, LI Jianhui, WEI Junchao, DAI Yanfeng, PENG Zhiping, CHEN Yiwang, LIU Tianxi

2015, 31(5):  890-894.  doi:10.1007/s40242-015-5075-5

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Poly(L-glutamic acid)(PLGA) was grafted onto the surface of mesoporous silica nanoparticles(MSN) via the ring opening polymerization of γ-benzyl-L-glutamate N-carboxyanhydride(BLG-NCA) and its subsequent deprotection of benzyl groups. The PLGA chains were cross-linked with cystamine, and thus forming a type of redox responsive drug delivery system(MSN-cPLGA). The structures were characterized by Fourier transform infrared spectrometry(FTIR), transmission electron microscopy(TEM) and energy disperse spectrometry(EDS), demonstrating that disulfide groups existed on the surfaces of MSN-cPLGA particles. The thermal gravimetric analysis(TGA) results show that the PLGA mass fraction is about 33.4% in the MSN-cPLGA hybrid. The in vitro drug release experiments showed that the MSN-cPLGA hybrid can realize the controlled release of model drugs(5-fluorouracil) in response to redox environment. Even 0.1 mmol/L dithiothreitol(DTT) can accelerate the drug release speed, and a concentration of 10.0 mmol/L DTT is higher enough to trigger the open of cross-linked PLGA network so as to realize rapid release of drugs. All the results demonstrate that the cross-linked PLGA chains on the surface of MSN could act as efficient gatekeepers to control the on-off of the pores, showing potential application in drug delivery system.



Biomimetic Fabrication of Polymer Film with High Adhesive Superhydrophobicity by Duplicating Locust Wing Surface

SUN Gang, FANG Yan, ZHI Heng, LI Zhengwen

2015, 31(5):  895-898.  doi:10.1007/s40242-015-5023-4

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Locust is a common flying insect. Locust wings were used as biomimetic templates to fabricate multi-functional polymer(polydimethylsiloxane, PDMS) films by soft lithography. The microstructure and wettability of the natural and artificial locust wing surfaces were investigated by means of a scanning electron microscope(SEM) and a video-based contact angle meter. The natural locust wing surface exhibits complicated hierarchical structures and high adhesive superhydrophobicity(contact angle 152°). The prepared polymer film faithfully reproduces the surface microstructures of the bio-template, and displays a good hydrophobicity and high adhesion(contact angle 144°). The complex wettability of the natural and artificial locust wing surfaces ascribes to the cooperative effect of hydrophobic composition and multi-dimensional rough microstructures. This work not only promotes our understanding of the wetting mechanism on bio-surfaces, but offers an inexpensive and effective approach for biomimetic fabrication of multi-functional interfacial materials.