Lixin Wu

Jilin University, Yung-chi, Jilin Sheng, China

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Publications (141)501.12 Total impact

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    ABSTRACT: A three-component supramolecular hybrid system based on host-guest recognition and electrostatic interaction has been developed for a consecutive chiral transfer from an alpha-cyclodextrin to cationic dyes via the bridge of a new azobenzene-grafted Anderson-type polyoxometalate cluster.
    Chemical Communications 08/2014; · 6.38 Impact Factor
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    ABSTRACT: The block copolymers (BCs), as structure-directing agents, co-assembling with nanoscale inorganic additives is an important route to fabricate nanostructured hybrid materials. In this work, we present a facile approach to fabricate hybrid micelles composed of BCs and polyoxometalates (POMs), in which the POM clusters are premodified with the groups that can specifically interact with a certain BC block. A representative POM (NH4)42[Mo132O372(CH3COO)30(H2O)72] (Mo132) is chosen as the example and encapsulated with cationic molecules containing carboxyphenyl groups through electrostatic interactions, and then the resulting hybrid complex can further co-assemble with poly(styrene-block-4-vinylpyridine) (PS-b-P4VP) through hydrogen bonding with the pyridine groups, which leads to the formation of hybrid micelles and the localization of Mo132 in the micelle cores. The micelles exhibit a high stability despite time and dilution. Furthermore, the fusion of the micelles can be readily adjusted by varying the length of PS blocks, which is promising to be used in constructing polymer-POM hybrid materials with discrete or continuous hybrid domains. This work is based on the electrostatic premodification of POMs and thus its concept is generally suitable for the whole anionic POM system, which may create a large class of BC-POM nanocomposites with tunable structures.
    Soft Matter 07/2014; · 3.91 Impact Factor
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    ABSTRACT: Surfactant-encapsulated polyoxometalate complexes are used as cluster suprasurfactants to transfer reduced graphene oxide (RGO) nanosheets from water to low polar organic solvents, which realizes the single-layer dispersion and the cluster-functionalization of RGO in one step.
    Chemical Communications 07/2014; · 6.38 Impact Factor
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    ABSTRACT: To explore the principle of chiral induction in inorganic clusters, chiral organic cations with two stereocenters, R- and S-BPEA, are used to encapsulate a series of polyoxometalates (POMs) bearing different structures and transition absorption bands in aqueous solution, constructing a series of chiral supramolecular complexes. Due to the induction of chiral organic cations, POMs possessing both chiral and achiral structures show an induced circular dichroism (ICD) effect. ICD signals in the absorption bands corresponding to ligand to metal charge transfer (LMCT) transitions, d-d transitions and intervalence charge transfer (IVCT) transitions are observed for different complexes. Moreover, the ICD of the POMs exhibits a direct correlation with the degree of POM distortion and the distance between the chiral center and the POM surface. The encapsulation of POMs with chiral organic cations via electrostatic interactions provides a facile and effective method for constructing optically pure POM-based materials.
    Dalton Transactions 05/2014; · 3.81 Impact Factor
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    ABSTRACT: A europium-substituted polyoxometalate (K13[Eu(SiW10MoO39)2]⋅28 H2O, EuSiWMo) can selectively bind to basic amino acids, namely, lysine, arginine, and histidine, and induce the emission enhancement of Eu3+ significantly. The mechanism is attributed to electrostatic interactions and hydrogen bonds between basic residues of the amino acids and negative charges of EuSiWMo based on the 1H NMR titration spectra of amino acids and time-resolved fluorescence decay curves of EuSiWMo.
    ChemPlusChem 05/2014;
  • Hui Ai, Yang Wang, Bao Li, Lixin Wu
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    ABSTRACT: Five single-side organic decorated Anderson-type molybdoaluminates have been synthesized from the reaction of the Na3(H2O)6[Al(OH)6Mo6O18]·2H2O cluster and RC(CH2OH)3 ligands [R = CH2OH, NH2, CH2CH3, NHCH2COOH, CH2OCH2C(CH2OH)3], followed by the addition of TBA·Br {TBA = [N(C4H9)4]+}. The prepared compounds possess an identical Anderson-type structural frame in each case, wherein three of the six hydroxy groups surrounding the AlIII heteroatom are substituted by one RC(CH2OH)3 group, forming asymmetric single-sided organically decorated clusters. The compounds demonstrate the simplest synthesis of covalent organic decoration for the single-sides of molybdoaluminates. All the prepared compounds in the present study were synthesized in aqueous solution and characterized by elemental and TG analysis, IR and 1H NMR spectroscopy, and single-crystal X-ray diffraction analysis. In addition, the supramolecular structures of these compounds based on the hydrogen bonding have also been discussed. The method reported here provides a common approach for the asymmetric functionalization of Anderson-type molybdoaluminates.
    Berichte der deutschen chemischen Gesellschaft 05/2014; · 2.94 Impact Factor
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    ABSTRACT: In this study, three hybrid films {[(PEI/P5W30)m/(PEI/PSS/PEI/GO@F)]n(PEI/P5W30)m} (m = 1, 3, 5; n = 15, 17, 18) (P5W30: [P5W30O110]15−; GO: graphene oxide; F: fluorescein) with green fluorescence have been successfully fabricated through a suitable structural design and alternate assembly of selected components. The fluorescence of the hybrid films can be reversibly switched by the electrochromism of the P5W30 component upon electrochemical modulation while the hybrid films display structural stability against the electrochemical process.
    J. Mater. Chem. C. 05/2014; 2(22).
  • Lei Shi, Yizhan Wang, Bao Li, Lixin Wu
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    ABSTRACT: In this paper, the chiral surfactants bearing two long alkyl chains with hydroxyl groups at their terminals were synthesized and employed to encapsulate a catalytically efficient polyoxometalate through electrostatic interaction. The obtained chiral surfactant-encapsulated polyoxometalate complexes, in which a defined chiral microenvironment surrounds the inorganic cluster, were covalently immobilized into the silica matrix via a sol-gel process. Kinetic resolution of racemic aromatic alcohols was selected as the model reaction to evaluate the chiral supramolecular hybrid catalysts. Up to 89% enantiomeric excess was obtained by varying the reaction conditions. Importantly, the change of loading values of the chiral surfactant-encapsulated polyoxometalates leads to mutative inner microstructures ranging from uniform dispersion to subsequent formation of nanocrystalline domains in the silica matrix. Such a structural evolution differentiates the density and stability of the chiral microenvironment, resulting in a regular change of enantioselectivity of the prepared asymmetric catalysts. Moreover, the fixation of the chiral microenvironment surrounding the polyoxometalates by covalent immobilization was proved to have a promoting effect on enantioselectivity. The present research uncovers the unique effect of immobilization on the kinetic resolution. The strategy helps to understand the influencing factors of enantioselectivity, and provides a convenient and efficient approach for the construction of supramolecular asymmetric catalysts based on chiral surfactant-encapsulated polyoxometalate complexes.
    Dalton Transactions 05/2014; · 3.81 Impact Factor
  • Wen Li, Lixin Wu
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    ABSTRACT: Supramolecular liquid crystals containing inorganic nanoclusters represent a promising avenue in the field of liquid crystals. The main motivation for developing those hybrid materials originates from the value-added combination between functional properties of inorganic nano-objects and the self-assembly behavior of organic LC molecules. This review highlights the recent progress regarding the nanocluster-contained supramolecular liquid crystals. Important factors affecting the liquid crystalline behaviors are systematically described and summarized. The driving forces behind the molecular self-assembly are discussed in depth. Finally, potential applications of the liquid-crystalline nanohybrids are prospected.
    Polymer International 03/2014; · 2.13 Impact Factor
  • Dan Li, Haolong Li, Lixin Wu
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    ABSTRACT: A series of hybrid supramolecular star polymers (SSPs) consisting of a polyoxometalate EuW10O369− (EuW10) core and different length of polystyrene arms have been fabricated by a “core-first” method, in which the anionic EuW10 clusters were firstly encapsulated by cationic molecules with trithioester terminal groups and subsequently polystyrene arms were grafted by reversible addition–fragmentation chain-transfer (RAFT) polymerization. The SSPs exhibit structurally dependent self-assembly behaviours in solution, at the air–water interface and solid state. It was found that the SSPs with short arms form large assemblies with a diameter over 100 nm in chloroform, while those with long arms tend to be mono-dispersed. Meanwhile, the distance between the EuW10 cores of adjacent SSPs in Langmuir monolayers and casting films can be precisely adjusted by PS arms, which leads to a tunable colour purity of EuW10 luminescence. This tight structure–property relationship enables the polyoxometalate-cored SSPs to act as potential building blocks for the construction of hybrid polymer materials with controllable functions.
    Polym. Chem. 02/2014; 5(6).
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    ABSTRACT: Two series of Bodipy-containing photochromic spirooxazine and spiropyran derivatives have been designed, synthesized and characterized by (1)H NMR, ESI mass spectrometry and elemental analysis. Their electrochemical and photochromic properties were investigated. The photophysical, ultrafast transient absorption, and fluorescence resonance energy transfer (FRET) properties from Bodipy (donor) to the ring-opened merocyanine (acceptor) were also studied. Upon photoexcitation, all the photochromic spirooxazine- and spiropyran-containing compounds exhibited reversible photochromism. Computational studies have been performed to provide further insights into the nature of the electronic transitions for the two classes of compounds. The rate constants and activation parameters for thermal bleaching reactions of compounds SO, SP-alkyne, 1-3, and 8-10 were determined through kinetic studies in acetonitrile. The thermal bleaching reaction rate of the spiropyran-containing compounds is found to be much slower than that of the spirooxazine-containing counterparts.
    ACS Applied Materials & Interfaces 01/2014; · 5.01 Impact Factor
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    ABSTRACT: A smart core-shell complex is designed to combine the catalytic reaction and the automatic separation through remote light control. Here, we present the induced amphiphilic behavior of a surfactant-encapsulated polyoxometalate complex with photo-responsive azobenzene units on the periphery. The reversible phase transfer of the complex shuttle between two incompatible phase termini, which is driven by the photoisomerization-induced polarity change, further facilitates the separation and recycle of the catalyst.
    Journal of the American Chemical Society 09/2013; · 10.68 Impact Factor
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    ABSTRACT: Supramolecular assembly: Spherical and stable hybrid assemblies based on a cationic polymer with spermine side chains and an anionic Gd(3+) -containing polyoxometalate cluster (GdW) are prepared by electrostatic interaction. The T1 -weighted MRI performance of GdW is enhanced about three times in the assemblies; meanwhile, the assemblies show good biocompatibility, which enables them to be promising candidates for MRI contrast agents.
    Chemistry 09/2013; · 5.93 Impact Factor
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    ABSTRACT: Chiral self-assembly of an azobenzene-grafted POM complex has been constructed through self-crosslinking by both the electrostatic and host-guest interactions and reversibly modulated by dynamic controlling of the isomerization of photoactive groups in the complex.
    Chemical Communications 09/2013; · 6.38 Impact Factor
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    ABSTRACT: A facile method to fabricate honeycomb-patterned polymer films bearing cavities that are locally decorated with inorganic component is developed in this study. By mixing poly(methyl methacrylate) dichloromethane solution containing P123 with polyoxometalate (POM) aqueous solution through shaking, a reversed hybrid microemulsion is obtained. The evaporation of solvent in the microemulsion on solid surface yields an ordered porous film accompanied by the accumulation of P123 and POMs on the inner surface of the cavities. The formation of patterned structure is proved to be independent from the type of POMs, but the size of the cavities can be adjusted to some extent by changing the concentration of surfactant and polymer, and the volume ratio of water and dichloromethane in the solution used for casting. The locally anchored POMs can be readily applied for the selective recognition of proteins. BSA and hemoglobin patterns are then fabricated through their electrostatic interactions with POMs. At lower pH, POM pattern could prior recognize hemoglobin from its mixed solution of BSA, generating a characteristic pattern. The reported work creates an efficient way of patterning organically incompatible components, such as water-soluble molecules and nanoparticles, on porous polymer films for the fabrication of multi-functional hybrid surface structures.
    Journal of Colloid and Interface Science 08/2013; · 3.17 Impact Factor
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    ABSTRACT: A new type of organic-inorganic hybrid supramolecular polymer has been prepared by using the base group modified polyoxometalate clusters as monomers, where the hydrogen bonds between the complementary base pairs act as the driving force.
    Chemical Communications 08/2013; · 6.38 Impact Factor
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    ABSTRACT: A series of cholesterol-/estradiol-appended alkynylplatinum(II) complexes with tridentate N-donor ligands, based on 2,6-bis(1-alkylpyrazol-3-yl)pyridine, has been synthesized and characterized by (1) H NMR spectroscopy, FAB-mass spectrometry, and elemental analysis. Their photophysical properties have also been investigated. Computational studies have been performed to provide insights into the nature of the electronic transitions. Some of the complexes have been found to form stable thermo- and mechanoresponsive supramolecular gels.
    Chemistry 07/2013; 19(30):9987-94. · 5.93 Impact Factor
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    ABSTRACT: Herein, we present an electrochemically assisted method for the reduction of graphene oxide (GO) and the assembly of polyoxometalate clusters on the reduced GO (rGO) nanosheets for the preparation of nanocomposites. In this method, the Keggin-type H4 SiW12 O40 (SiW12 ) is used as an electrocatalyst. During the reduction process, SiW12 transfers the electrons from the electrode to GO, leading to a deep reduction of GO in which the content of oxygen-containing groups is decreased to around 5 %. Meanwhile, the strong adsorption effect between the SiW12 clusters and rGO nanosheets induces the spontaneous assembly of SiW12 on rGO in a uniformly dispersed state, forming a porous, powder-type nanocomposite. More importantly, the nanocomposite shows an enhanced capacity of 275 mAh g(-1) as a cathode active material for lithium storage, which is 1.7 times that of the pure SiW12 . This enhancement is attributed to the synergistic effect of the conductive rGO support and the well-dispersed state of the SiW12 clusters, which facilitate the electron transfer and lithium-ion diffusion, respectively. Considering the facile, mild, and environmentally benign features of this method, it is reasonable as a general route for the incorporation of more types of functional polyoxometalates onto graphene matrices; this may allow the creation of nanocomposites for versatile applications, for example, in the fields of catalysis, electronics, and energy storage.
    Chemistry 07/2013; · 5.93 Impact Factor
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    ABSTRACT: A series of cationic dendrons bearing triethylene glycol monomethyl ether terminal groups of different generations have been synthesized and used to encapsulate an inorganic polyanionic cluster [K12.5 Na1.5 (NaP5 W30 O110 )] through electrostatic interactions. The resulting dendritic cation-encapsulated polyoxometalate (POM) complexes, cluster-dendrimers, are soluble in water and exhibit lower critical solution temperatures (LCST). The thermoresponsivities of these complexes in aqueous solutions were studied by turbidimetry and variable-temperature (1) H NMR spectroscopy. The observed cloud points show a remarkable dependence on the generation of the dendrons. Complexes composed of first-generation dendrons exhibit no obvious thermoresponsive properties, but for complexes bearing second-generation dendrons, the LCST decreases as the number of dendritic cations around the POM cluster increases. Complexes composed of third-generation cations underwent reversible aggregation and disaggregation upon heating and cooling, respectively. This thermally induced self-aggregation was characterized by DLS and TEM. In addition, the effects of salt and solvent on the LCST were investigated. This research demonstrates a new type of thermoresponsive dendritic organic-inorganic hybrid complex and provides a general route to the endowment of POMs with temperature-sensitive properties through electrostatic interactions.
    Chemistry 06/2013; · 5.93 Impact Factor
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    ABSTRACT: Polyoxometalate (POM) complex (DODA)2 [Mo6 O19 ] with a symmetrical linear structure was prepared conveniently by replacing the tetrabutylammonium (TBA) counterions of Lindquist-type cluster (TBA)2 [Mo6 O19 ] with cationic surfactant dioctadecyldimethylammonium (DODA). A helical self-assembled structure of the complex was formed in dichloromethane/propanol. The dynamically reversible transformation between helical and spherical assemblies on alternate UV irradiation and H2 O2 oxidation was characterized by SEM, TEM, and UV/Vis studies. The redox-controlled morphology change is modulated by variation of the electrostatic interactions between the inorganic polyanion and the organic cation DODA through controlling the redox properties of the POM component, as shown by the XRD, X-ray photoelectron spectroscopic, and (1) H NMR measurements. The strategy applied herein is a unique example of targeted smart and helical assembly of POM complexes.
    Chemistry 04/2013; · 5.93 Impact Factor

Publication Stats

469 Citations
501.12 Total Impact Points

Institutions

  • 2001–2014
    • Jilin University
      • • State Key Laboratory of Supramolecular Structure and Materials
      • • College of Chemistry
      Yung-chi, Jilin Sheng, China
    • University of Münster
      • Institut für Physikalische Chemie
      Münster, North Rhine-Westphalia, Germany
  • 2011–2013
    • Northeast Normal University
      • Department of Chemistry
      Hsin-ching, Jilin Sheng, China