Zhiyong Guo

Iowa State University, Ames, Iowa, United States

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Publications (30)142.47 Total impact

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    ABSTRACT: A new porphyrin-based microporous MOF, {Mn(II)0.5[Mn(II)4Cl(Mn(III)Cl-ttzpp)2(H2O)4]}·(DEF)20·(CH3OH)18·(H2O)12 (UTSA-57), has been constructed from {5,10,15,20-tetrakis[4-(2,3,4,5-tetrazolyl)phenyl]porphyrinato} manganese(III) chloride as the metalloligand. The MOF adopts the rare scu topology with one-dimensional square nanotube-like channels of about 20 Å. UTSA-57a exhibits permanent porosity and displays moderately high performance for C2H2/CH4 separation at room temperature.
    Inorganic Chemistry 12/2014; 54(1). DOI:10.1021/ic502116k · 4.79 Impact Factor
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    ABSTRACT: A ketone functionalized luminescent terbium metal-organic framework has been realized for the highly selective and sensitive sensing of aniline.
    Chemical Communications 11/2014; DOI:10.1039/C4CC06729K · 6.38 Impact Factor
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    ABSTRACT: Synthesis of a new cobalt-based MOF constructed from a tricarboxylic acid linker.•Compound 1 displays unique (2,3,10)-connected trinodal topology.•Compound 1 represents a rare example of MOF possessing free carboxylic acids.•The magnetic property of compound 1 has been investigated.
    Inorganic Chemistry Communications 10/2014; DOI:10.1016/j.inoche.2014.10.030 · 2.06 Impact Factor
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    ABSTRACT: The host–guest interaction between metal ions (Pt2+ and Cu2+) and a zirconium metal–organic framework (UiO-66-NH2) was explored using dynamic nuclear polarization-enhanced 15N{1H} CPMAS NMR spectroscopy supported by X-ray absorption spectroscopy and density functional calculations. The combined experimental results conclude that each Pt2+ coordinates with two NH2 groups from the MOF and two Cl− from the metal precursor, whereas Cu2+ do not form chemical bonds with the NH2 groups of the MOF framework. Density functional calculations reveal that Pt2+ prefers a square-planar structure with the four ligands and resides in the octahedral cage of the MOF in either cis or trans configurations.
    Chemistry - A European Journal 10/2014; DOI:10.1002/chem.201403884 · 5.93 Impact Factor
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    ABSTRACT: A bifunctional Zr-MOF catalyst containing palladium nanoclusters (NCs) has been developed. The formation of Pd NCs was confirmed by transmission electron microscopy (TEM) and extended X-ray absorption fine structure (EXAFS). Combining the oxidation activity of Pd NCs and the acetalization activity of the Lewis acid sites in UiO-66-NH2, this catalyst (Pd@UiO-66-NH2) exhibits excellent catalytic activity and selectivity in a one-pot tandem oxidation-acetalization reaction. This catalyst shows 99.9% selectivity to benzaldehyde ethylene acetal in the tandem reaction of benzyl alcohol and ethylene glycol at 99.9% conversion of benzyl alcohol. We also examined various substituted benzyl alcohols and found that alcohols with electron-donating groups showed better conversion and selectivity compared to those with electron-withdrawing groups. We further proved that there was no leaching of active catalytic species during the reaction and the catalyst can be recycled at least five times without significant deactivation.
    ACS Catalysis 08/2014; DOI:10.1021/cs5006635 · 7.57 Impact Factor
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    ABSTRACT: The interaction of guest Pt(II) ions with UiO-66-X (X = -NH2, -H, -NO2, -OMe, -F) series Metal-Organic-Frameworks (MOFs) in aqueous solution was investigated using in situ X-ray absorption spectroscopy. All of these MOFs were found to be able to coordinate with Pt(II) ions. The Pt(II) ions in UiO-66-X MOFs generally coordinate with 1.6-2.4 Cl and 1.4-2.4 N or O atoms. We also studied the time evolution of the coordination structure, and found that Pt(II) maintained a coordination number of four throughout the whole process. Furthermore, the kinetic parameters of the interaction of Pt(II) ions with UiO-66-X series MOFs (X = -NH2, -H, -NO2, -OMe, -F) were determined by combinational linear fitting of extended X-ray absorption fine structure (EXAFS) spectra of the samples. The Pt(II) adsorption rate constants were found to be 0.063 h(-1) for UiO-66-NH2, and 0.011-0.017 h(-1) for other UiO-66-X (X = -H, -NO2, -OMe, -F) MOFs, which means Pt(II) adsorption in UiO-66-NH2 is 4-6 times faster than that in other UiO-66 series MOFs. FTIR studies suggested that the carboxyl groups could be the major host ligands binding with Pt(II) ions in UiO-66 series MOFs, except for UiO-66-NH2, in which amino groups coordinate with Pt(II) ions.
    The Journal of Physical Chemistry B 08/2014; DOI:10.1021/jp5066456 · 3.38 Impact Factor
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    ABSTRACT: A highly selective and robust catalyst based on Pt nanoclusters (NCs) confined inside the cavities of an amino-functionalized Zr-terephthalate metal–organic framework, UiO-66-NH2 was developed. The Pt NCs are monodisperse and confined in the cavities of UiO-66-NH2 even at 10.7 wt% Pt loading. This confinement was further confirmed by comparing the catalytic performance of Pt NCs confined inside and supported on the external surface of the MOF in the hydrogenation of ethylene, 1-hexene, and 1,3-cyclooctadiene. The benefit of confining Pt NCs inside UiO-66-NH2 was also demonstrated by evaluating their performance in the chemoselective hydrogenation of cinnamaldehyde. We found that both high selectivity to cinnamyl alcohol and high conversion of cinnamaldehyde can be achieved using the MOF-confined Pt nanocluster catalyst, while we could not achieve high cinnamyl alcohol selectivity on Pt NCs supported on the external surface of the MOF. The catalyst can be recycled ten times without any loss in its activity and selectivity.To confirm the stability of the recycled catalysts, we conducted kinetic studies for the first 20 hours of reaction during four recycle runs on the catalyst. Both the conversion and selectivity are almost overlapping for the four runs, which indicates the catalyst is very stable under the employed reaction conditions.
    ACS Catalysis 03/2014; 4:1340. DOI:10.1021/cs400982n · 7.57 Impact Factor
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    ABSTRACT: We report the synthesis, structural characterization, thermal stability study, and regeneration of nanostructured catalysts made of 2.9 nm Pt nanoparticles sandwiched between a 180 nm SiO2 core and a mesoporous SiO2 shell. The SiO2 shell consists of 2.5 nm channels that are aligned perpendicular to the surface of the SiO2 core. The nanostructure mimics Pt nanoparticles that sit in mesoporous SiO2 wells (Pt@MSWs). By using synchrotron-based small-angle X-ray scattering, we were able to prove the ordered structure of the aligned mesoporous shell. By using high-temperature cyclohexane dehydrogenation as a model reaction, we found that the Pt@MSWs of different well depths showed stable activity at 500 °C after the induction period. Conversely, a control catalyst, SiO2 -sphere-supported Pt nanoparticles without a mesoporous SiO2 shell (Pt/SiO2 ), was deactivated. We deliberately deactivated the Pt@MSWs catalyst with a 50 nm deep well by using carbon deposition induced by a low H2 /cyclohexane ratio. The deactivated Pt@MSWs catalyst was regenerated by calcination at 500 °C with 20 % O2 balanced with He. After the regeneration treatments, the activity of the Pt@MSWs catalyst was fully restored. Our results suggest that the nanostructured catalysts-Pt nanoparticles confined inside mesoporous SiO2 wells-are stable and regenerable for treatments and reactions that require high temperatures.
    ChemSusChem 10/2013; 6(10). DOI:10.1002/cssc.201300524 · 7.48 Impact Factor
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    ABSTRACT: Three isostructural interwoven 3,4-connected mesoporous metal-organic frameworks of pto-a topology (UTSA-28-Cu, UTSA-28-Zn, and UTSA-28-Mn) were synthesized and structurally characterized. Because of their metastable nature, their gas sorption properties are highly dependent on the metal ions and activation profiles. The most stable, UTSA-28a-Cu, exhibits promising gas storage and separation capacities.
    Inorganic Chemistry 09/2013; 52(19). DOI:10.1021/ic401870e · 4.79 Impact Factor
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    ABSTRACT: A series of lanthanide anionic metal–organic frameworks, [NH2(CH3)2][Ln(MDIP)(H2O)] (Ln = Pr (1), Nd (2), Sm (3), Eu (4), Gd (5), Tb (6), Dy (7); H4MDIP = methylenediisophthalic acid) and [NH2(CH3)2][Ln(MDIP)(H2O)]·0.5NH(CH3)2 (Ln = Er (8), Tm (9), Yb (10)), have been synthesized and characterized. In compounds 1–7, the adjacent Ln3+ ions are intraconnected to form infinite metal-carboxylate oxygen chain-shaped building blocks along the [001] direction. In compounds 8–10, MDIP ligands bridge dinuclear lanthanide centers to form three-dimensional frameworks which can be rationalized as a (4,8)-connected topological net with the Schläfli symbol of (410.614.84)(45.6)2. Dimethylamine cations occupy the vacancy of all the compounds as counterions. The photophysical properties of trivalent Pr, Nd, Sm, Eu, Tb, Dy, Er, Yb compounds at room temperature were investigated and showed that MDIP is an efficient sensitizer of the luminescence of both the Tb3+ ion emitting visible light and the Yb3+ ion emitting in the near-IR. Antiferromagnetic interactions between Gd3+ ions were observed from magnetic susceptibility data.
    Crystal Growth & Design 03/2012; 12(4):1808–1815. DOI:10.1021/cg201283a · 4.56 Impact Factor
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    ABSTRACT: A luminescent mixed lanthanide metal-organic framework approach has been realized to explore luminescent thermometers. The targeted self-referencing luminescent thermometer Eu(0.0069)Tb(0.9931)-DMBDC (DMBDC = 2, 5-dimethoxy-1, 4-benzenedicarboxylate) based on two emissions of Tb(3+) at 545 nm and Eu(3+) at 613 nm is not only more robust, reliable, and instantaneous but also has higher sensitivity than the parent MOF Tb-DMBDC based on one emission at a wide range from 10 to 300 K.
    Journal of the American Chemical Society 03/2012; 134(9):3979-82. DOI:10.1021/ja2108036 · 11.44 Impact Factor
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    ABSTRACT: Three open frameworks, [Ni(pnta)2]·1.3DMF (1), [Zn2(pnta)3(OH)]·2DMF (2), and [Cd(pnta)2]·3.8DMF (3), were obtained by solvothermal reactions between 6-(pyridin-4-yl)nicotinic acid (Hpnta) and nickel(II), zinc(II) and cadmium(II) nitrate, respectively. Compound 1 is a chiral framework with a fourfold interpenetrated diamondoid network structure and two types of chiral channels. Compound 2 also possesses the fourfold interpenetrated adamantanoid architecture with helical rhombic nanotube-like channels, each of which has two sides of double-layer walls and two other sides of single-layer walls. Compound 3 is a rarely reported double-walled framework with bcu topology. The luminescent properties of compounds 2 and 3 have been studied in the solid state at room temperature.
    CrystEngComm 02/2012; 14(5):1681-1686. DOI:10.1039/C2CE05948G · 3.86 Impact Factor
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    ABSTRACT: Three three-dimensional coordination polymers, namely, [NH2(CH3)2][Co2(MDIP)(OH)(H2O)]·C3H7NO·H2O (1), [NH2(CH3)2]2[Mn3(MDIP)2]·2C3H7NO (2), and [NH2(CH3)2][Mg3(MDIP)(HMDIP)(C3H7NO)]·4H2O (3) (DMF = N,N′-dimethylformamide), have been synthesized by the solvothermal reaction of Co(II), Mn(II), or Mg(II) salts with methylenediisophthalic acid (H4MDIP). All compounds have been characterized by thermogravimetric analysis, IR spectroscopy, elemental and single-crystal X-ray diffraction analyses. Complexes 1–3 are anionic frameworks with [NH2(CH3)2]+ ions occupying the voids, built upon tetra-, tri- and asymmetrical trimetallic cores, respectively. In particular, the asymmetrical trinuclear Mg(II) unit in complex 3 was scarcely observed. Topological analyses show that the three compounds possess binodal (4,8)-connected alb topology with a Schläfli symbol of (410.614.84)(45.6)2. Magnetic investigations indicate that antiferromagnetic couplings are dominant in compounds 1 and 2.
    CrystEngComm 09/2011; 13(20):6057-6064. DOI:10.1039/C1CE05149K · 3.86 Impact Factor
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    ABSTRACT: Five new three/two-fold interpenetrated coordination polymers, namely, [Cd(mfda)(L1)] (1), [Cd(efda)(L1)] (2), [Zn2(mfda)2(L2)]·DMF·H2O (3), [Zn2(efda)2(L2)]·(DMF)0.25, (4) and [Cd2(mfda)2(L2)2]·DMF·H2O (5) (H2mfda = 9,9-dimethylfluorene-2,7-dicarboxylic acid, H2efda = 9,9-diethylfluorene-2,7-dicarboxylic acid, L1 = Methylene bis(3,5-dimethylpyrazole) and L2 = 1,4-bis(4-pyridyl)-2,3-diaza-1,3-butadiene), have been synthesized under solvent-thermal conditions with mixed ligands. Compounds 1 and 2 are isostructural and possess two-dimensional (6, 3) layered structures containing two kinds of rings. Three equivalent (6, 3) net interpenetrate in a parallel fashion to form an unprecedented mat-like 2D sheet. Compounds 3 and 4 are almost identical in structure and display threefold interpenetrating α–Po net structures. Compound 5 displays a twofold interpenetrated 3D 6-connected net with α–Po topology. The luminescent properties of these compounds have been studied in the solid state at room temperature.
    CrystEngComm 04/2011; 13(8):2935-2941. DOI:10.1039/C0CE00662A · 3.86 Impact Factor
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    ABSTRACT: The first near-infrared luminescent ytterbium metal-organic framework has been realized for the highly selective and sensitive sensing of small molecules.
    Chemical Communications 04/2011; 47(19):5551-3. DOI:10.1039/c1cc10897b · 6.38 Impact Factor
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    Angewandte Chemie International Edition 03/2011; 50(14):3178-81. DOI:10.1002/anie.201007583 · 11.34 Impact Factor
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    ABSTRACT: In this paper, we report an efficient strategy to design bright blue and blue–green electroluminescent (EL) devices by slightly doping tris(8-hydroxyquinoline) aluminum (Alq3) into N,N′-diphenyl-N,N′-bis(1-naphthyl)-1,1′-diphenyl-4,4′-diamine (NPB) as the light-emitting layer (EML). Bright EL devices with tunable spectra were obtained by strictly controlling the doping concentration of Alq3. With increasing current density, EL efficiencies of these devices increase first and then decrease gradually after reaching the maximum. Analyzing the current density–voltage (J−V) characteristics of hole-only and electron-only devices, we found the presence of Alq3 molecules in EML not only facilitates the injection of electrons from hole block layer (HBL) into EML but also stays the transport of holes in EML, thus causing significant enhancement of EL efficiency and brightness due to improved carriers balance and broadening of recombination zone. More interestingly, the doping concentration of Alq3 strongly influences the injection and transport processes of electrons, thus determining the distribution of holes and electrons on NPB and Alq3 molecules.
    Journal of Luminescence 11/2010; 130(11):2265-2270. DOI:10.1016/j.jlumin.2010.07.003 · 2.37 Impact Factor
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    ABSTRACT: Methylenediisophthalic acid (H(4)MDIP), as semi-rigid 'V'-shaped carboxylate ligands, react with CoO, NiO and Cu(NO(3))(2)·3H(2)O to give three novel coordination polymers [H(3)O](2)[Co(3)(MDIP)(2)]·2DMF (1), [Ni(2)(HMDIP)(μ(2)-OH)(H(2)O)(3)(DMF)]·4H(2)O·DMF (2) and [Cu(3)(MDIP)(μ(2)-OH)(2)(H(2)O)(4)]·6.5H(2)O (3) (DMF = N,N'-dimethylformamide). All compounds have been characterized by thermogravimetric analysis, IR spectroscopy, elemental and single-crystal X-ray diffraction analyses. Complex 1 is an unusual open anionic framework that is defined as the metal-organic replica of fluorite. Both 2 and 3 features a 3D open framework with one-dimensional elliptical channels and R- and L-helical chains, and their resulting frameworks can be rationalized as crb and pts topology respectively. An interesting feature of complex 3 is the presence of the linear Cu(3) units that is formed by carboxylate and μ(2)-hydroxyl groups linking three Cu(II) metal centers. Magnetic investigations indicate that ferromagnetic couplings are dominant in the three compounds.
    Dalton Transactions 10/2010; 39(38):9123-30. DOI:10.1039/c001655a · 4.10 Impact Factor
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    ABSTRACT: The NIR-luminescent ErQ3 nano-/microstructures have been successfully synthesized through a simple microemulsion route. Various morphologies, including nanorods, bundles, and urchins, have been achieved by tuning the fundamental experimental parameters, such as the organic solvents and the concentration of cetyltrimethylammonium bromide (CTAB). The results from SEM images indicate that a solvent with lower polar and higher boiling-point would result in nanorods, while higher concentrations of CTAB and solvents with higher polar and lower boiling-point would prefer the formation of bundles or urchins. The molecular formula of the products being ErQ3 can be deduced by the elemental analysis and thermal gravimetric analysis (TGA) and can be further confirmed by the X-ray powder diffraction (XRD) and Fourier-transform infrared spectra (FTIR). A self-assembly growth mechanism has been proposed to explain our system based on the obtained results. Following excitation of the absorption of the ligand, all the ErQ3 nano-/microstructures show characteristic emissions centered at 1534 nm due to the typical 4I13/2 → 4I15/2 transition of the Er3+ ion. In addition, the luminescence properties of the as-obtained samples are dependent on the morphologies and sizes of the ErQ3 nano-/microstructures, which is a higher dimensionality, leading to stronger luminescence intensity.
    Crystal Growth & Design 09/2010; 10(10). DOI:10.1021/cg101051r · 4.56 Impact Factor
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    ABSTRACT: Four novel diimine rhenium(I) carbonyl complexes with the formula [Re(CO)3(L)Br], where L = 2-(4-(9H-carbazol-9-yl)phenyl)-1H-imidazo[4,5-f][1,10]phenanthroline (P1), 2-(4-(3,6-di-tert-butyl-9H-carbazol-9-yl)phenyl)-1H-imidazo-[4,5-f][1,10]phenanthroline (P2), 2-(4-(6-(9H-carbazol-9-yl)-9H-3,9′-bicarbazol-9-yl)phenyl)-1H-imidazo[4,5-f][1,10]phenanthroline (D1), and 2-(4-(3′,6′-di-tert-butyl-6-(3,6-di-tert-butyl-9H-carbazol-9-yl)-9H-3,9′-bicarbazol-9-yl)phenyl)-1H-imidazo[4,5-f][1,10]phenanthroline (D2), have been successfully synthesized and fully characterized by 1H NMR, IR, and UV–Vis, etc. The luminescence quantum yields (LQYs) of the parent Re(I) complexes P1 and P2 are 0.13 and 0.16, respectively, which are much higher than the previously reported Re(I)dendrimers. The HOMOs and the LUMOs of P1 and P2 are calculated to be mainly composed of [d(Re) + π(CO + Br)] and π*(L) orbital, respectively. However, those of the Re(I)dendrimersD1 (LQY = 0.066) and D2 (LQY = 0.0048) are mainly localized on ligand L, indicating that the component of the metal-to-ligand charge-transfer dπ (Re) →π*(N–N) (MLCT) transitions in P1 and P2 should be more than those in D1 and D2. As a result, the higher LQYs of P1 and P2 are tentatively assigned to the disturbance of the MLCT transitions during the photoluminescence process.
    Dalton Transactions 11/2009; DOI:10.1039/B912939A · 4.10 Impact Factor

Publication Stats

565 Citations
142.47 Total Impact Points

Institutions

  • 2013–2014
    • Iowa State University
      • Department of Chemistry
      Ames, Iowa, United States
  • 2012–2014
    • University of Texas at San Antonio
      • Department of Chemistry
      San Antonio, Texas, United States
  • 2007–2014
    • Chinese Academy of Sciences
      • Key Laboratory of Rare Earth Chemistry and Physics
      Peping, Beijing, China