scholarly journals Interrogating the Behaviour of a Styryl Dye Interacting with a Mesoscopic 2D-MOF and Its Luminescent Vapochromic Sensing

2021 ◽  
Vol 23 (1) ◽  
pp. 330
Author(s):  
Maria Rosaria di Nunzio ◽  
Mario Gutiérrez ◽  
José María Moreno ◽  
Avelino Corma ◽  
Urbano Díaz ◽  
...  
Keyword(s):  
Metal Organic Framework ◽  
Bathochromic Shift ◽  
Emission Spectra ◽  
Visible Absorption ◽  
Time Resolved ◽  
Styryl Dye ◽  
Metal Organic ◽  
Uv Visible ◽  
Low Dimensional ◽  
Amine Compounds

In this contribution, we report on the solid-state-photodynamical properties and further applications of a low dimensional composite material composed by the luminescent trans-4-(dicyanomethylene)-2-methyl-6-(4-dimethylaminostyryl)-4H-pyran (DCM) dye interacting with a two-dimensional-metal organic framework (2D-MOF), Al-ITQ-HB. Three different samples with increasing concentration of DCM are synthesized and characterized. The broad UV-visible absorption spectra of the DCM/Al-ITQ-HB composites reflect the presence of different species of DCM molecules (monomers and aggregates). In contrast, the emission spectra are narrower and exhibit a bathochromic shift upon increasing the DCM concentration, in agreeance with the formation of adsorbed aggregates. Time-resolved picosecond (ps)-experiments reveal multi-exponential behaviors of the excited composites, further confirming the heterogeneous nature of the samples. Remarkably, DCM/Al-ITQ-HB fluorescence is sensitive to vapors of electron donor aromatic amine compounds like aniline, methylaniline, and benzylamine due to a H-bonding-induced electron transfer (ET) process from the analyte to the surface-adsorbed DCM. These findings bring new insights on the photobehavior of a well-known dye when interacting with a 2D-MOF and its possible application in sensing aniline derivatives.

scholarly journals Elucidating the Drug Release from Metal-Organic Framework Nanocomposites via in Situ Synchrotron Microspectroscopy and Theoretical Modelling

2019 ◽  
Author(s):  
Barbara Souza ◽  
Lorenzo Dona ◽  
Kirill Titov ◽  
Paolo Bruzzese ◽  
Zhixin Zeng ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Drug Release ◽  
Density Functional ◽  
Metal Organic Framework ◽  
Density Functional Theory Calculations ◽  
Theoretical Modelling ◽  
Time Resolved ◽  
Drug Molecules ◽  
Metal Organic

Nanocomposites comprising metal-organic frameworks (MOFs) embedded in a polymeric matrix are promising carriers for drug delivery applications. While understanding the chemical and physical transformations of MOFs during the release of confined drug molecules is challenging, this is central to devising better ways for controlled release of therapeutic agents. Herein we demonstrate the efficacy of synchrotron microspectroscopy to track the in situ release of 5-fluorouracil (5-FU) anticancer drug molecules from a drug@MOF/polymer composite (5-FU@HKUST-1/polyurethane). Using experimental time-resolved infrared spectra jointly with newly developed density functional theory calculations, we reveal the detailed dynamics of vibrational motions underpinning the dissociation of 5-FU bound to the framework of HKUST-1 upon water exposure. We discover that HKUST-1 creates hydrophilic channels within the hydrophobic polyurethane matrix hence helping to tune drug release rate. The synergy between a hydrophilic MOF with a hydrophobic polymer can be harnessed to engineer a tunable nanocomposite that alleviates the unwanted burst effect commonly encountered in drug delivery.<br>

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 Elucidating the Drug Release from Metal-Organic Framework Nanocomposites via in Situ Synchrotron Microspectroscopy and Theoretical Modelling

2019 ◽  
Author(s):  
Barbara Souza ◽  
Lorenzo Dona ◽  
Kirill Titov ◽  
Paolo Bruzzese ◽  
Zhixin Zeng ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Drug Release ◽  
Density Functional ◽  
Metal Organic Framework ◽  
Density Functional Theory Calculations ◽  
Theoretical Modelling ◽  
Time Resolved ◽  
Drug Molecules ◽  
Metal Organic

Nanocomposites comprising metal-organic frameworks (MOFs) embedded in a polymeric matrix are promising carriers for drug delivery applications. While understanding the chemical and physical transformations of MOFs during the release of confined drug molecules is challenging, this is central to devising better ways for controlled release of therapeutic agents. Herein we demonstrate the efficacy of synchrotron microspectroscopy to track the in situ release of 5-fluorouracil (5-FU) anticancer drug molecules from a drug@MOF/polymer composite (5-FU@HKUST-1/polyurethane). Using experimental time-resolved infrared spectra jointly with newly developed density functional theory calculations, we reveal the detailed dynamics of vibrational motions underpinning the dissociation of 5-FU bound to the framework of HKUST-1 upon water exposure. We discover that HKUST-1 creates hydrophilic channels within the hydrophobic polyurethane matrix hence helping to tune drug release rate. The synergy between a hydrophilic MOF with a hydrophobic polymer can be harnessed to engineer a tunable nanocomposite that alleviates the unwanted burst effect commonly encountered in drug delivery.<br>

scholarly journals In Situ Time-Resolved Decomposition of β-Hydride Phase in Palladium Nanoparticles Coated with Metal-Organic Framework

Metals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 810
Author(s):  
Mikhail V. Kirichkov ◽  
Aram L. Bugaev ◽  
Alina A. Skorynina ◽  
Vera V. Butova ◽  
Andriy P. Budnyk ◽  
...  
Keyword(s):  
Phase Transition ◽  
Particle Size ◽  
Hydrogen Adsorption ◽  
Metal Organic Framework ◽  
Pd Nanoparticles ◽  
Time Resolved ◽  
Metal Organic ◽  
Hydride Phases ◽  
Organic Framework

The formation of palladium hydrides is a well-known phenomenon, observed for both bulk and nanosized samples. The kinetics of hydrogen adsorption/desorption strongly depends on the particle size and shape, as well as the type of support and/or coating of the particles. In addition, the structural properties of hydride phases and their distribution also depend on the particle size. In this work, we report on the in situ characterization of palladium nanocubes coated with HKUST-1 metal-organic framework (Pd@HKUST-1) during desorption of hydrogen by means of synchrotron-based time-resolved X-ray powder diffraction. A slower hydrogen desorption, compared to smaller sized Pd nanoparticles was observed. Rietveld refinement of the time-resolved data revealed the remarkable stability of the lattice parameters of α- and β-hydride phases of palladium during the α- to β- phase transition, denoting the behavior more similar to the bulk materials than nanoparticles. The stability in the crystal sizes for both α- and β-hydride phases during the phase transition indicates that no sub-domains are formed within a single particle during the phase transition.

Solvent exchange in a metal–organic framework single crystal monitored by dynamicin situX-ray diffraction

2017 ◽  
Vol 73 (4) ◽  
pp. 669-674 ◽  
Author(s):  
Jordan M. Cox ◽  
Ian M. Walton ◽  
Gage Bateman ◽  
Cassidy A. Benson ◽  
Travis Mitchell ◽  
...  
Keyword(s):  
Rational Design ◽  
Metal Organic Framework ◽  
X Ray Diffraction ◽  
Guest Molecules ◽  
Time Resolved ◽  
Ethanol Solvate ◽  
Significant Step ◽  
Metal Organic ◽  
Flexible Metal ◽  
Organic Framework

Understanding the processes by which porous solid-state materials adsorb and release guest molecules would represent a significant step towards developing rational design principles for functional porous materials. To elucidate the process of liquid exchange in these materials, dynamicin situX-ray diffraction techniques have been developed which utilize liquid-phase chemical stimuli. Using these time-resolved diffraction techniques, the ethanol solvation process in a flexible metal–organic framework [Co(AIP)(bpy)0.5(H2O)]·2H2O was examined. The measurements provide important insight into the nature of the chemical transformation in this system including the presence of a previously unreported neat ethanol solvate structure.

Femtosecond Time-Resolved UV−Visible Absorption Spectroscopy oftrans-Azobenzene in Solution

1996 ◽  
Vol 100 (32) ◽  
pp. 13338-13341 ◽  
Author(s):  
Igor K. Lednev ◽  
Tian-Qing Ye ◽  
Ronald E. Hester ◽  
John N. Moore
Keyword(s):  
Absorption Spectroscopy ◽  
Visible Absorption ◽  
Time Resolved ◽  
Uv Visible ◽  
Visible Absorption Spectroscopy

scholarly journals In Situ, Time-Resolved, and Mechanistic Studies of Metal–Organic Framework Nucleation and Growth

2018 ◽  
Vol 118 (7) ◽  
pp. 3681-3721 ◽  
Author(s):  
Mary J. Van Vleet ◽  
Tingting Weng ◽  
Xinyi Li ◽  
J.R. Schmidt
Keyword(s):  
Metal Organic Framework ◽  
Nucleation And Growth ◽  
Mechanistic Studies ◽  
Time Resolved ◽  
Metal Organic ◽  
Organic Framework

scholarly journals Femto- to Millisecond Time-Resolved Photodynamics of a Double-Functionalized Push–Pull Organic Linker: Potential Candidate for Optoelectronically Active MOFs

2020 ◽  
Vol 21 (12) ◽  
pp. 4366
Author(s):  
Mario Gutiérrez ◽  
Lucie Duplouy-Armani ◽  
Lorenzo Angiolini ◽  
Mercedes Pintado-Sierra ◽  
Félix Sánchez ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Metal Organic Framework ◽  
Direct Consequence ◽  
Potential Candidate ◽  
Time Resolved ◽  
Slowing Down ◽  
Electronically Excited ◽  
Donor Acceptor ◽  
Metal Organic ◽  
Viscous Solvents

The design of improved organic linkers for the further engineering of smarter metal–organic framework (MOF) materials has become a paramount task for a wide number of material scientists. In this report, a luminescent double-functionalized push–pull (electron donor–acceptor) archetype organic molecule, dimethyl 4-amino-8-cyanonaphthalene-2,6-dicarboxylate (Me2CANADC), has been synthesized and characterized. The optical steady-state properties of Me2CANADC are strongly influenced by the surrounding environment as a direct consequence of its strong charge transfer (CT) character. The relaxation from its first electronically excited singlet state follows a double pathway: (1) on one side deactivating from its local excited (LE) state in the sub-picosecond or picosecond time domain, and (2) on the other side undergoing an ultrafast intramolecular charge transfer (ICT) reaction that is slowing down in viscous solvents. The deactivation to the ground state of these species with CT character is the origin of the Me2CANADC luminescence, and they present solvent-dependent lifetime values ranging from 8 to 18 ns. The slow photodynamics of Me2CANADC unveils the coexistence of a non-emissive triplet excited state and the formation of a long-lived charge separated state (2 µs). These observations highlight the promising optical properties of Me2CANADC linker, opening a window for the design of new functional MOFs with huge potential to be applied in the fields of luminescent sensing and optoelectronics.

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