pH-Controlled Assembly of 3D and 2D Zinc-based Metal-Organic Frameworks with Tetrazole Ligands

2017 ◽  
Author(s):  
Felipe Herrera ◽  
Ignacio Chi-Duran ◽  
Javier Enriquez ◽  
Carolina Manquian ◽  
Kerry Wrighton-Araneda ◽  
...  
Keyword(s):  
Structural Diversity ◽  
Molar Ratio ◽  
Aqua Complex ◽  
Initial Reaction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Metal Organic ◽  
Metal Ligand

<div> <div> <div> <p>We report the synthesis and structural diversity of Zn(II) MOF with in situ formation of tetrazole ligand 3-ptz [3-ptz = 5-(3-pyridyl)tetrazolate], as a function pH. By varying the initial reaction pH, we obtain high-quality crystals of the non-centrosymmetric 3D MOF Zn(3-ptz)2, mixed phases involving the zinc-aqua complex [Zn(H2O)4(3-ptz)2]·4H2O, and 2D MOF crystals Zn(OH)(3-ptz) with a tunable micro-rod morphology, keeping reaction time, temperature and metal-ligand molar ratio constants. Structures are characterized by X-ray diffraction, scanning electron microscopy, FTIR and UV-Vis spectroscopy. We discuss the observed structural diversity in terms of the relative abundance of hydroxo-zinc species in solution for different values of pH. </p> </div> </div> </div>

pH-Controlled Assembly of 3D and 2D Zinc-based Metal-Organic Frameworks with Tetrazole Ligands

2017 ◽  
Author(s):  
Felipe Herrera ◽  
Ignacio Chi-Duran ◽  
Javier Enriquez ◽  
Carolina Manquian ◽  
Kerry Wrighton-Araneda ◽  
...  
Keyword(s):  
Structural Diversity ◽  
Molar Ratio ◽  
Aqua Complex ◽  
Initial Reaction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Metal Organic ◽  
Metal Ligand

<div> <div> <div> <p>We report the synthesis and structural diversity of Zn(II) MOF with in situ formation of tetrazole ligand 3-ptz [3-ptz = 5-(3-pyridyl)tetrazolate], as a function pH. By varying the initial reaction pH, we obtain high-quality crystals of the non-centrosymmetric 3D MOF Zn(3-ptz)2, mixed phases involving the zinc-aqua complex [Zn(H2O)4(3-ptz)2]·4H2O, and 2D MOF crystals Zn(OH)(3-ptz) with a tunable micro-rod morphology, keeping reaction time, temperature and metal-ligand molar ratio constants. Structures are characterized by X-ray diffraction, scanning electron microscopy, FTIR and UV-Vis spectroscopy. We discuss the observed structural diversity in terms of the relative abundance of hydroxo-zinc species in solution for different values of pH. </p> </div> </div> </div>

scholarly journals In situ X‐ray Diffraction Investigation of the Crystallisation of Perfluorinated Ce(IV)‐based Metal‐Organic Frameworks with UiO‐66 and MIL‐140 architectures

2021 ◽  
Author(s):  
Stephen J. I. Shearan ◽  
Jannick Jacobsen ◽  
Ferdinando Costantino ◽  
Roberto D’Amato ◽  
Dmitri Novikov ◽  
...  
Keyword(s):  
Metal Organic Frameworks ◽  
X Ray Diffraction ◽  
X Ray ◽  
Metal Organic

scholarly journals Exceptional adsorption-induced cluster and network deformation in the flexible metal–organic framework DUT-8(Ni) observed by in situ X-ray diffraction and EXAFS

2015 ◽  
Vol 17 (26) ◽  
pp. 17471-17479 ◽  
Author(s):  
Volodymyr Bon ◽  
Nicole Klein ◽  
Irena Senkovska ◽  
Andreas Heerwig ◽  
Jürgen Getzschmann ◽  
...  
Keyword(s):  
Metal Organic Framework ◽  
X Ray Diffraction ◽  
X Ray ◽  
Gate Opening ◽  
Metal Organic ◽  
Flexible Metal ◽  
Organic Framework

The “gate opening” mechanism in flexible MOF Ni2(2,6-ndc)2dabco was elucidated in detail.

scholarly journals Elucidating the Structural Evolution of a Highy Porous Responsive Metal-Organic Framework (DUT-49(M)) upon Guests Desorption by Time-Resolved In-Situ Powder X-Ray Diffraction

2020 ◽  
Author(s):  
Bikash Garai ◽  
Volodymyr Bon ◽  
Francesco Walenszus ◽  
Azat Khadiev ◽  
Dmitri Novikov ◽  
...  
Keyword(s):  
Adsorption Isotherms ◽  
Metal Organic Framework ◽  
Structural Evolution ◽  
Structural Transformations ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
Metal Organic ◽  
Subcritical Fluid

Variation in the metal centres of M-M paddle-wheel SBU results in the formation of isostructural DUT-49(M) frameworks. However, the porosity of the framework was found to be different for each of the structures. While a high and moderate porosity was obtained for DUT-49(Cu) and DUT-49(Ni), respectively, other members of the series [DUT-49(M); M= Mn, Fe, Co, Zn, Cd] show very low porosity and shapes of the adsorption isotherms which is not expected for op phases of these MOFs. Investigation on those MOFs revealed that those frameworks undergo structural collapse during the solvent removal at the activation step. Thus, herein, we aimed to study the detailed structural transformations that are possibly occurring during the removal of the subcritical fluid from the framework.

scholarly journals In situ X-ray Diffraction Investigation of the Crystallisation of Perfluorinated Ce(IV)-based Metal-Organic Frameworks with UiO-66 and MIL-140 architectures

2020 ◽  
Author(s):  
Stephen Shearan ◽  
Jannick Jacobsen ◽  
Ferdinando Costantino ◽  
Roberto D’Amato ◽  
Dmitri Novikov ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Metal Organic Frameworks ◽  
Building Blocks ◽  
Nucleation And Growth ◽  
X Ray Diffraction ◽  
X Ray ◽  
Rate Determining Step ◽  
Wide Range ◽  
Metal Organic

We report on the results of a thorough <i>in situ</i> synchrotron powder X-ray diffraction study of the crystallisation in aqueous medium of two recently discovered perfluorinated Ce(IV)-based metal-organic frameworks (MOFs), analogues of the already well investigated Zr(IV)-based UiO-66 and MIL-140A, namely, F4_UiO-66(Ce) and F4_MIL-140A(Ce). The two MOFs were originally obtained in pure form in similar conditions, using ammonium cerium nitrate and tetrafluoroterephthalic acid as building blocks, and small variations of the reaction parameters were found to yield mixed phases. Here, we investigate the crystallisation of these compounds <i>in situ</i> in a wide range of conditions, varying parameters such as temperature, amount of the protonation modulator nitric acid (HNO<sub>3</sub>) and amount of the coordination modulator acetic acid (AcOH). When only HNO<sub>3</sub> is present in the reaction environment, F4_MIL-140A(Ce) is obtained as a pure phase. Heating preferentially accelerates nucleation, which becomes rate determining below 57 °C, whereas the modulator influences nucleation and crystal growth to a similar extent. Upon addition of AcOH to the system, alongside HNO<sub>3</sub>, mixed-phased products, consisting of F4_MIL-140A(Ce) and F4_UiO-66(Ce), are obtained. In these conditions, F4_UiO-66(Ce) is always formed faster and no interconversion between the two phases occurs. In the case of F4_UiO-66(Ce), crystal growth is always the rate determining step. An increase in the amount of HNO<sub>3</sub> slows down both nucleation and growth rates for F4_MIL-140A(Ce), whereas nucleation is mainly affected for F4_UiO-66(Ce). In addition, a higher amount HNO<sub>3</sub> favours the formation of F4_MIL-140A(Ce). Similarly, increasing the amount of AcOH leads to slowing down of the nucleation and growth rate, but favours the formation of F4_UiO-66(Ce). The pure F4_UiO-66(Ce) phase could also be obtained when using larger amounts of AcOH in the presence of minimal HNO<sub>3</sub>. Based on these <i>in situ</i> results, a new optimised route to achieving a pure, high quality F4_MIL-140A(Ce) phase in mild conditions (60 °C, 1 h) is also identified.

Photocatalytic Activity of CuO/ZnO Heterostructure Nanocrystals under UV-Visible Light Irradiation

2014 ◽  
Vol 787 ◽  
pp. 35-40 ◽  
Author(s):  
Xiao Yan Zhou ◽  
Peng Wei Zhou ◽  
Hao Guo ◽  
Bo Yang ◽  
Ru Fei Ren
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Cuo Nanoparticles ◽  
Light Irradiation ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Uv Visible

The p-n junction photocatalysts, p-CuO (at. 0-25%)/n-ZnO nanocomposite were prepared through hydrothermal method without using any organic solvent or surfactant. The as-prepared samples were characterized by X-ray diffraction, scanning electron microscopy, energy dispersive X-Ray spectroscopy, and UV-vis spectroscopy. The results demonstrated that the CuO/ZnO nanocomposite presented a two-dimensional morphology composed of sheet-like ZnO nanostructures adorned with CuO nanoparticles. The photocatalytic activity of CuO/ZnO with different Cu/Zn molar rations and pure ZnO synthesized by the identical synthetic route were evaluated by degrading methylene blue (MB) dye under UV-visible light irradiation. The CuO/ZnO with Cu/Zn molar ratio of 4% exhibits the highest photocatalytic activity compared that of the other photocatalysts under the identical conditions. It is mainly attributed to the increased charge separation rate in the nanocomposite and the extended photo-responding range.

Combined synchrotron x-ray diffraction and micro-Raman for following in situ the growth of solution-deposited YBa2Cu3O7 thin films

2005 ◽  
Vol 20 (12) ◽  
pp. 3270-3273 ◽  
Author(s):  
F. Berberich ◽  
H. Graafsma ◽  
B. Rousseau ◽  
A. Canizares ◽  
R. Ramy Ratiarison ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Additional Information ◽  
Micro Raman Spectroscopy ◽  
High Temperature Process ◽  
Structural Growth ◽  
Metal Organic ◽  
Insight Into

A unique combination of in situ synchrotron x-ray diffraction and in situ micro-Raman spectroscopy was used to study the growth process of YBa2Cu3O6+x films obtained by metal organic decomposition using trifluoroacetate precursor on LaAlO3 substrates. The techniques give complementary information: x-ray diffraction gives insight into the structural growth, whereas micro-Raman spectroscopy gives information of the chemical composition with additional information on the texture. To perform both experiments in situ, a special high-temperature process chamber was designed.

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