Jing-Wei Xu

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Name: 徐经伟; JingWei Xu

Organization: Chinese Academy of Science , China

Department: Changchun Institute of Applied Chemistry

Title: Researcher/Professor(PhD)

TOPICS

Inorganic Chemistry

Analytical Chemistry

Chemicals
References

An Ullmann CO Coupling Reaction Catalyzed by Magnetic Copper Ferrite Nanoparticles

Co-reporter:Shuliang Yang;Cunqi Wu;Hua Zhou;Yanqin Yang;Yongxia Zhao;Chenxu Wang;Wei Yang;Jingwei Xu

Advanced Synthesis & Catalysis 2013 Volume 355( Issue 1) pp:53-58

Publication Date(Web):

DOI:10.1002/adsc.201200600

Abstract

Herein, an efficient method for the Ullmann CO coupling reaction between various kinds of phenols and aryl halides, including amino, ketone, cyano, methyl, methoxy, fluoro, chloro and bromo derivatives, is described. The catalyst used, copper ferrite (CuFe₂O₄) nanoparticles, are easily made, air-stable, and of low cost. The catalyst can be recycled easily just by using an external magnet. Even in the presence of sensitive substituents, the reaction proceeds successfully to provide the desired products in high yields without protection of other functional groups.

Two multinuclear GdIII macrocyclic complexes as contrast agents with high relaxivity and stability using rigid linkers

Co-reporter:Guiyan Zhao, Cuige Lu, Haolong Li, Yanmeng Xiao, Wenwen Zhang, Xinxiu Fang, Pixin Wang, Xuexun Fang, Jingwei Xu, Wei Yang

Inorganica Chimica Acta 2013 Volume 406() pp:146-152

Publication Date(Web):1 September 2013

DOI:10.1016/j.ica.2013.07.015

•Two T1-weighted MRI contrast agents have been synthesized and characterized.•The rigid linkages improved the relaxivity of the agents.•The complexes exhibited high thermodynamic stability and kinetic inertness.Two macrocyclic chelating MRI agents (Gd-DO3A)3–TAB and (Gd-DO3A)2–DAB have been successfully synthesized by appending three and two Gd-DO3A moieties upon the acetylbenzene derivatives, respectively. The longitudinal relaxivity of (Gd-DO3A)3–TAB measured at 20 MHz, 37 °C and pH 7.0 is 6.1 mMGd−1 s−1, 74% higher than that of the mononuclear clinical agent [Gd(DOTA)(H2O)]−. A 30% or 16% increase in relaxivity was observed upon addition of 0.72 mM bovine serum albumin (BSA) or 10-fold of diamagnetic ion La3+. More importantly, the thermodynamic stability and kinetic inertness of (Gd-DO3A)3–TAB are comparable to or better than that of [Gd(DTPA)(H2O)]2−. The luminescence lifetime study on the corresponding (Eu-DO3A)3–TAB analog demonstrated that the agent had one inner-sphere water coordinated to the Eu3+ center within the complex. The cytotoxicity study indicated that the toxicity of the agent was low with IC50 = 18 mM. In addition, the characterization of its dinuclear analog (Gd-DO3A)2–DAB has also been investigated.(Gd-DO3A)3–TAB possessed higher water proton relaxivity, high thermodynamic and kinetic stability, and low toxicity, which facilitate the further development of clinical applicable multinuclear MR contrast agents.

Alkoxylation reactions of aryl halides catalyzed by magnetic copper ferrite

Co-reporter:Shuliang Yang, Wenbing Xie, Hua Zhou, Cunqi Wu, Yanqin Yang, Jiajia Niu, Wei Yang, Jingwei Xu

Tetrahedron 2013 69(16) pp: 3415-3418

Publication Date(Web):

DOI:10.1016/j.tet.2013.02.077

Blue fluorescent protein analogs as chemosensors for Zn2+

Co-reporter:Xinxiu Fang, Haolong Li, Guiyan Zhao, Xuexun Fang, Jingwei Xu, Wei Yang

Biosensors and Bioelectronics 2013 Volume 42() pp:308-313

Publication Date(Web):15 April 2013

DOI:10.1016/j.bios.2012.09.065

Three chemosensors for Zn2+ were designed and synthesized based on the chromophore of the blue fluorescent protein (BFP). Among them, IMMPI (4-((1H-imidazol-2-yl)methylene)-1-methyl-2-phenyl-1H-imidazol-5(4H)-one) contained one BFP chromophore unit, which sequestered Zn2+ with nitrogen in the two imidazole rings, while Di-IMMPI-a and Di-IMMPI-o contained two IMMPI units that were connected together using an alkane and a methoxy chain, respectively. All three molecules selectively interacted with Zn2+ with a 1:1 mode. Di-IMMPI-a had a dissociation constant <0.03 μM for Zn2+, more than 30 folds stronger than that of IMMPI. The fluorescences of IMMPI, Di-IMMPI-a, and Di-IMMPI-o were turned on upon the binding of Zn2+, accompanied by the quantum yields enhancing from <0.002 to 0.352, 0.451, and 0.194, respectively. Fluorescence images showed that Di-IMMPI-a responded to Zn2+ in cell cytosol. Our work demonstrated the potentiality for the development of practical Zn2+ sensors based on the isolated BFP chromophores without the proteinframe.Highlights► Three chemosensors for Zn2+ were designed based on the chromophore of BFP. ► IMMPI contains two imidazole rings as the chromophore of BFP. ► Di-IMMPI-a and Di-IMMPI-o contain two IMMPI units. ► IMMPIs (IMMPI, Di-IMMPI-a and Di-IMMPI-o) bound to Zn2+ with high affinity and selectivity. ► Di-IMMPI-a is the most sensitive fluorescent Zn2+ chemosensor based on GFP and its derivatives at present.

Di-nuclear nonionic magnetic resonance contrast agents using pyrazinyl linking centers

Co-reporter:Guiyan zhao, Haolong Li, Cuige Lu, Yanmeng Xiao, Xinxiu Fang, Pixin Wang, Xuexun Fang, Kun Zhao, Xinlong Li, Shengguo Yin, Jingwei Xu and Wei Yang

RSC Advances 2012 vol. 2(Issue 16) pp:6404-6407

Publication Date(Web):18 Apr 2012

DOI:10.1039/C2RA20450A

Two di-nuclear non-ionic MRI contrast agents, (Gd-DO3A)2-BMQX and (Gd-DO3A)2-BMP, have been designed and synthesized by fusing the DO3A units together with a quinoxalinyl or pyrazinyl moiety. They have improved longitudinal relaxivities of 5.23 and 5.16 mM Gd−1 s−1, respectively, at 20 MHz magnet, 37 °C and pH 7.0. In addition, they possess high thermodynamic stability and kinetic inertness. The cytotoxicity studies indicated that the toxicity of these two agents were low. All these properties satisfy the requirements for clinical applications.

pH-controlled synthesis of two new coordination polymers modeled by pyridine-2,4-dicarboxylic acid

Co-reporter:Fan-Jin Meng, Heng-Qing Jia, Ning-Hai Hu, Jing-Wei Xu

Inorganic Chemistry Communications 2012 Volume 21() pp:186-190

Publication Date(Web):July 2012

DOI:10.1016/j.inoche.2012.04.012

Two new cadmium compounds [Cd3 (OH)2 (2,4-pydc)2] (1) and [Cd2(2,4-pydc)2(bpe)]·2H2O (2) (2,4-pydcH2 = pyridine-2,4-dicarboxylic acid, bpe = 1,2-bis(4-pyridyl)ethene) have been prepared under hydrothermal conditions at different pH values. The compounds were characterized by elemental analyses, IR spectra and thermogravimetric analyses and their structures were determined by single-crystal X-ray diffraction analysis. Compound 1 has a 3D framework constructed by 2D Cd-O(OH) layers and pillared 2,4-pydc ligands. Compound 2 also displays a 3D metal-organic framework with the Cd(II) centers connected by 2,4-pydc and bpe ligands. The differences in the structures indicate that the change of pH value has significant effects on the formation and structures of the final compounds. In addition, the luminescent properties of compounds 1–2 have also been studied.Under different pH values, two new cadmium coordination polymers have been synthesized by hydrothermal method. Three new coordination modes of 2,4-pydc ligand are observed for the first time. Comparing compounds 1 and 2, we can find that the pH value can have a profound influence on the final structures.Highlights► Two new cadmium coordination polymers were prepared by hydrothermal method. ► The change of pH value has a profound influence on the structures of the products. ► Both of the cadmium coordination polymers emit intense fluorescence.

Metal- and ligand-free Ullmann-type C–O and C–N coupling reactions promoted by potassium tert-butoxide

Co-reporter:Shuliang Yang, Cunqi Wu, Mingbo Ruan, Yanqin Yang, Yongxia Zhao, Jiajia Niu, Wei Yang, Jingwei Xu

Tetrahedron Letters 2012 Volume 53(Issue 33) pp:4288-4292

Publication Date(Web):15 August 2012

DOI:10.1016/j.tetlet.2012.05.131

A simple, metal- and ligand-free procedure for the Ullmann-type C–O coupling reactions has been achieved by allowing aryl bromides to react with a variety of phenols in the presence of t-BuOK. Moderate to excellent yields of O-arylation products are obtained under mild conditions in a short time. In addition, two examples of C–N coupling reactions are also reported. A benzyne mechanism is proposed according to the experiment data.

Alignment of Single-Walled Carbon Nanotubes with Ferroelectric Liquid Crystal

Co-reporter:Yongxia Zhao, Yanmeng Xiao, Shuliang Yang, Jingwei Xu, Wei Yang, Meiye Li, Dongmei Wang, and Yunchun Zhou

The Journal of Physical Chemistry C 2012 Volume 116(Issue 31) pp:16694-16699

Publication Date(Web):July 1, 2012

DOI:10.1021/jp211778z

Single-walled carbon nanotubes (SWCNTs) are aligned by using a ferroelectric liquid crystal (FLC) named [4-(3)-(S)-methyl-2-(S)-chloropentanoyloxy)]-4′-nonyloxy-biphenyl. The scanning electron microscope (SEM) is utilized to investigate the alignment of the SWCNTs in the smectic A phase. Fourier Transform Infrared spectroscopy (FTIR) and Raman spectroscopy are utilized to investigate the interaction between these two species. The SEM images show that SWCNTs can be well aligned along the smectic layers. A new peak appears at 1702 cm–1 in the FTIR spectra in the SWCNT hybrids, which indicate that charge transfer occurring from the hexagonal rings of the SWCNTs to the C═O groups of the FLC molecules that contact directly with the SWCNTs. To our knowledge, this is the first time we observe the charge transfer effect by FTIR. Similarly, a new peak at 763 cm–1 is also found in the Raman spectrum of the SWCNT hybrid that results from the charge transfer effect between the SWCNTs and the C–Cl groups of the FLC. The π–π stacking and charge transfer effect together make the SWCNTs align unidirectionally along the smectic layers instead of in the direction of the molecular long axis.

The Zinc-Dependent Fluorescence of a Synthetic GFP-Like Chromophore in Organic Solvents

Co-reporter:Juntao Kang;Xinxiu Fang;Xiankai Chen;Guiyan Zhao;Aimin Ren;Jingwei Xu;Wei Yang

European Journal of Inorganic Chemistry 2011 Volume 2011( Issue 34) pp:5322-5327

Publication Date(Web):

DOI:10.1002/ejic.201100605

Abstract

A synthetic green fluorescent protein analogue showed Zn²⁺-induced fluorescence in organic solvents (Φ = 0.07 at r.t. and up to 0.3 at low temperature). The experimental observations and theoretical calculations suggest that Zn²⁺ binding inhibits the free rotation of an aryl–alkene bond, which allows excited molecules to relax through the emission pathway instead of the thermodynamic pathway. The solvent influenced the fluorescence intensities and wavelengths by direct or indirect interactions with the molecules.

Investigations on Ferroelectric Liquid Crystal by High Resolution TEM and Solid State 13C NMR

Co-reporter:Yongxia Zhao, Yanqin Yang, Jingwei Xu, Wei Yang, Yunchun Zhou, Zijiang Jiang, and Xin Ge

The Journal of Physical Chemistry B 2011 Volume 115(Issue 45) pp:13175-13180

Publication Date(Web):October 3, 2011

DOI:10.1021/jp2077962

In order to investigate the structural and dynamical properties of ferroelectric liquid crystal (FLC) in different phases a model compound [4-(3)-(S)-methyl-2-(S)-chloropentanoyloxy)]-4′-nonyloxy-biphenyl (3M2CPNOB) is synthesized. High resolution transmission electron microscopy (HR-TEM) is applied to observe the morphology of 3M2CPNOB and temperature-dependent solid state 13C NMR to record 13C chemical shifts at different phases. A liquid nitrogen quenching method is used to maintain the conformation of the mesophases for HR-TEM experiments. TEM images show that all the smectic A (SmA), smectic C* (SmC*) and crystalline phases have lamellar morphology. The interplanar distances in the crystalline phase are smaller than those in SmA and SmC* phases because of denser arrangement of the molecules. Both 13C chemical shifts and line shape vary with different phases. The experimental results suggest that SmC* phase as an intermediate occurs in the anisotropy transition process from SmA to crystalline phase, the helical structure of the SmC* phase unwinds in the magnetic field and the conformations of the SmA and isotropic phase are very similar.

Comparison of headspace solid-phase microextraction with conventional extraction for the analysis of the volatile components in Melia azedarach

Co-reporter:Yanqin Yang, Yanmeng Xiao, Baofeng Liu, Xuexun Fang, Wei Yang, Jingwei Xu

Talanta 2011 Volume 86() pp:356-361

Publication Date(Web):30 October 2011

DOI:10.1016/j.talanta.2011.09.028

The volatile compositions of Melia azedarach were studied by headspace solid-phase microextraction (HS-SPME). The result was compared with that obtained by soxhlet extraction (SE) and ultrasonic extraction (UAE). 79 compounds were identified in this study, among which 64 compounds were first reported. The experimental parameters including fiber type (PDMS, PDMS-DVB and CAR-PDMS), desorption time, extraction temperature and time were investigated. 37 compounds were obtained by HS-SPME, including curcumene (33.25%), α-cadinol (11.16%), α-muurolene (8.72%), copaene (5.04%), β-bisabolene (3.41%), and α-selinene (2.97%). The result suggested that the HS-SPME method is a powerful analytic tool and complementary to traditional methods for the determination of the volatile compounds in Chinese herbs.Highlights► HS-SPME, SE and UAE methods are used to study the volatile compositions of Melia azedarach. ► The HS-SPME method is first used with simple, fast and solvent-free merits. ► 79 compounds are identified, among which 64 compounds are first reported. ► 37 compounds are identified by the HS-SPME alone.

A synthesized GFP analogue emits via a hydrogen-bonding system

Co-reporter:Juntao Kang, Guiyan Zhao, Jingwei Xu and Wei Yang

Chemical Communications 2010 vol. 46(Issue 16) pp:2868-2870

Publication Date(Web):05 Mar 2010

DOI:10.1039/B927461H

Two GFP analogues o-HBDI and o-HBMO have been designed and synthesized. The former shows no fluorescence while the latter shows strong fluorescence due to the formation of an intramolecular hydrogen-bond. At low temperatures, both molecules have strong fluorescence.

Construction of Metal−Organic Frameworks with Tetranuclear Metal Clusters: Hydrothermal Synthesis, Structure, and Magnetic Properties

Co-reporter:Guan-Hua Wang, Yong-Qian Lei, Ning Wang, Ren-Ling He, Heng-Qing Jia, Ning-Hai Hu and Jing-Wei Xu

Crystal Growth & Design 2010 Volume 10(Issue 2) pp:534-540

Publication Date(Web):January 15, 2010

DOI:10.1021/cg900694k

Five novel coordination polymers [Co4(OABDC)2(OH)2(H2O)4]n·(H2O)4.4n (1), [Ni4(OABDC)2(OH)2(H2O)4]n·(H2O)4n (2) (OABDC = 5-oxyacetateisophthalate), [Co2(OABDC)(bpe)(OH)]n·(H2O)2.9n (3), [Zn2(OABDC)(bpe)(OH)]n·(H2O)3.5n (4) (bpe = 1,2-bis(4-pyridyl)ethylene), and [Co2(OABDC)(bpy)(OH)]n·(H2O)2.2n (5) (bpy = 4,4′-bipyridine) have been acquired at similar hydrothermal conditions. All compounds are constructed from tetranuclear [M4(μ3-OH)2] (M = Co for 1, 3, and 5, Ni for 2, Zn for 4) clusters. Compounds 1 and 2 are isomorphous, in which the M4(OH)2 units act as 6-connected nodes and the frameworks are two-dimensional (2D) (3,6)-connected nets with the rare CdI2 type. If considering the strong H-bond interactions between neighboring layers, both exhibit three-dimensional (3D) microporous networks with channels running along the [100] direction. Complexes 3 and 4 are also isomorphous, in which the 2D CdI2-based layer was pillared by bpe spacers; thus channels occur along the [100] direction. While adopting bpy instead of the bpe ligand, smaller channels are observed along the [100] direction for 5. The last three compounds all feature 3D networks with one of the scarce (3,8)-connected (43)2.(46.618.84) topologies. Magnetic susceptibility measurements indicate that compound 1 shows strong antiferromagnetic behavior, while 2 exhibits strong ferromagnetic behavior.

Metal–organic frameworks based on the pyridine-2,3-dicarboxylate and a flexible bispyridyl ligand: syntheses, structures, and photoluminescence

Co-reporter:Guan-Hua Wang, Zhi-Gang Li, Heng-Qing Jia, Ning-Hai Hu and Jing-Wei Xu

CrystEngComm 2009 vol. 11(Issue 2) pp:292-297

Publication Date(Web):07 Nov 2008

DOI:10.1039/B809557D

Three new metal–organic coordination polymers, [Cu(2,3-pydc)(bpp)]·2.5H2O (1), [Zn(2,3-pydc)(bpp)]·2.5H2O (2) and [Cd(2,3-pydc)(bpp)(H2O)]·3H2O (3) (2,3-pydcH2 = pyridine-2,3-dicarboxylic acid, bpp = 1,3-bis(4-pyridyl)propane), have been synthesized at room temperature. All complexes have metal ions serving as 4-connected nodes but represent two quite different structural motifs. Complexes 1 and 2 are isomorphous, both of which feature 2D → 3D parallel interpenetration. Each two-dimensional (2D) layer with (4, 4) topology is interlocked by two nearest neighbours, one above and one below, thus leading to an unusual 3D motif. Complex 3 has a non-interpenetrating 3D CdSO4 framework with cavities occupied by uncoordinated water molecules. The compounds have been characterized by infrared spectroscopy, elemental analysis, thermogravimetric analysis and X-ray crystallography. The photoluminescent studies of 2 and 3 show that both complexes exhibit intense fluorescent emissions at room temperature.

Physical and mechanical properties of dental nanocomposites composed of aliphatic epoxy resin and epoxidized aromatic hyperbranched polymers

Co-reporter:Yujie Zhang;Daohong Zhang;Chuangye Qin;Jingwei Xu

Polymer Composites 2009 Volume 30( Issue 2) pp:176-181

Publication Date(Web):

DOI:10.1002/pc.20549

Abstract

Aliphatic epoxy resin (UVR6105) and epoxidized aromatic hyperbranched polymers (HBP) were used as dental resin matrixes, siliane-treated inorganic nanoparticles as inorganic fillers, ethyl 4-dimethylaminobenzoate, camphorquinone, and 4-[(2-hydroxytetradecyl)oxy] phenyl-phenyliodoniumhexafluoroantimonate (CD1012) as initiators to formulate new kinds of dental nanocomposites. Their physical and mechanical properties were tested and the inner structure was observed by using scanning electron microscope (SEM) and transmission electron microscope (TEM), respectively. The 7 series thermal analysis system was used to determine the glass transition temperature of dental resins. Compressive strengths of dental nanocomposites are lower, diametral tensile strengths are comparable with, flexural strengths are higher than those of commercial hybrid composite (Spectrum-TPH). The addition of HBP decreased the glass transition temperature of aliphatic epoxy resin. SEM photo micrograph shows that the nanoparticles were well dispersed and inlayed in the resin matrixes. TEM photo micrograph shows that the inner structure of dental resins presents club-shaped. Epoxidized aromatic hyperbranched polymer can strengthen and toughen aliphatic epoxy resin. These nanocomposites are potential for dental application. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers

Copper(I)-Catalyzed Aryl Bromides To Form Intermolecular and Intramolecular Carbon−Oxygen Bonds

Co-reporter:Jiajia Niu, Pengran Guo, Juntao Kang, Zhigang Li, Jingwei Xu and Shaojing Hu

The Journal of Organic Chemistry 2009 Volume 74(Issue 14) pp:5075-5078

Publication Date(Web):May 28, 2009

DOI:10.1021/jo900600m

A highly efficient Cu-catalyzed C−O bond-forming reaction of alcohol and aryl bromides has been developed. This transformation was realized through the use of copper(I) iodide as a catalyst, 8-hydroxyquinoline as a ligand, and K3PO4 as a base. A variety of functionalized substrates were found to react under these reaction conditions to provide products in good to excellent yields.

Elimination of matrix effect and spectral interference by two compactly combined separations in the determination of Cd in geological samples with high Mo, Zr or Sn contents by ICP-MS

Co-reporter:Taicheng Duan, Xuejie Song, Pengran Guo, Hongfei Li, Lihua Pan, Hangting Chen and Jingwei Xu

Journal of Analytical Atomic Spectrometry 2007 vol. 22(Issue 4) pp:403-406

Publication Date(Web):31 Jan 2007

DOI:10.1039/B610685D

The determination of Cd in geological samples with high Mo, Zr or Sn contents by ICP-MS suffered from matrix effects and severe spectral interferences. In this work solvent and solid phase extractions (SPE) were combined and both matrix and spectral interference free determinations were realized. After solvent extraction with an acidic extractant, interferences from Sn and Zr were reduced over 1000 fold, and Mo about 250 fold, while matrix elements could be effectively removed by a SPE column. A linear working curve could be obtained between Cd concentrations of 0.2–20 μg L−1, with a correlation coefficient of 0.9992. Cd recoveries in both separation systems were shown to be near 100%, and a total enrichment factor could reach 22. Feasibility of the established method was demonstrated by analyzing three soil geological standard reference materials with high Mo, Zr or Sn contents. The results showed that the established method was accurate, fast, low in procedural blank value, and good in Cd recovery.

Vibrational spectroscopic investigation of light-induced polymerization process of epoxy resin, polytetrahydrofuran and spirobislactone

Co-reporter:Yujie Zhang;Jingwei Xu;Zhengjun Chen;Chuangye Qin;Yanli Dou

Polymer International 2007 Volume 56(Issue 7) pp:

Publication Date(Web):12 JAN 2007

DOI:10.1002/pi.2224

The light-induced polymerization process of bisphenol F diglycidyl ether (BFDGE), 5,5′-dicarboxylic-7,7′-dioxo-2,2′-spirodi(benzotetrahydrofuran) (DCSBL) and polytetrahydrofuran (pTHF-250) was studied. 4-[(2-Hydroxytetradecyl)oxy]phenyl-phenyliodoniumhexafluoroantimonate, camphorquinone and ethyl 4-dimethylaminobenzoate were used as a photoinitiator system. The polymerization process was induced by light and monitored using Fourier transform infrared spectroscopy. A novel combination-initiation polymerization process was proposed: first, cationic copolymerization of BFDGE and pTHF-250 was initiated by the photoinitiator system and heat was released by this polymerization; then, copolymerization of BFDGE and DCSBL was induced by that heat while pTHF-250 served as an anionic initiator. Copyright © 2007 Society of Chemical Industry

A synthesized GFP analogue emits via a hydrogen-bonding system

Co-reporter:Juntao Kang, Guiyan Zhao, Jingwei Xu and Wei Yang

Chemical Communications 2010 - vol. 46(Issue 16) pp:NaN2870-2870

Publication Date(Web):2010/03/05

DOI:10.1039/B927461H

Elimination of matrix effect and spectral interference by two compactly combined separations in the determination of Cd in geological samples with high Mo, Zr or Sn contents by ICP-MS

Co-reporter:Taicheng Duan, Xuejie Song, Pengran Guo, Hongfei Li, Lihua Pan, Hangting Chen and Jingwei Xu

Journal of Analytical Atomic Spectrometry 2007 - vol. 22(Issue 4) pp:NaN406-406

Publication Date(Web):2007/01/31

DOI:10.1039/B610685D