Search results for "Metal-Organic Framework"
showing 10 items of 194 documents
Ligand engineering in Cu(ii) paddle wheel metal–organic frameworks for enhanced semiconductivity
2020
We report the electronic structure of two metal-organic frameworks (MOFs) with copper paddle wheel nodes connected by a N2(C2H4)3 (DABCO) ligand with accessible nitrogen lone pairs. The coordination is predicted, from first-principles density functional theory, to enable electronic pathways that could facilitate charge carrier mobility. Calculated frontier crystal orbitals indicate extended electronic communication in DMOF-1, but not in MOF-649. This feature is confirmed by bandstructure calculations and effective masses of the valence band egde. We explain the origin of the frontier orbitals of both MOFs based on the energy and symmetry alignment of the underlying building blocks. The effe…
Ultrathin Films of 2D Hofmann-Type Coordination Polymers: Influence of Pillaring Linkers on Structural Flexibility and Vertical Charge Transport
2019
Searching for novel materials and controlling their nanostructuration into electronic devices is a challenging task ahead of chemists and chemical engineers. Even more so when this new application requires an exquisite control over the morphology, crystallinity, roughness and orientation of the films produced. In this context, it is of critical importance to analyze the influence of the chemical composition of perspective materials on their properties at the nanoscale. We report the fabrication of ultrathin films (thickness < 30 nm) of a family of FeII Hofmann-like coordination polymers by using an optimized liquid phase epitaxy (LPE) set-up. The series [Fe(L)2{Pt(CN)4}] (L = pyridine, pyri…
Elucidating Gating Effects for Hydrogen Sorption in MFU-4-Type Triazolate-Based Metal-Organic Frameworks Featuring Different Pore Sizes
2011
A highly porous member of isoreticular MFU-4-type frameworks, [Zn(5)Cl(4)(BTDD)(3)] (MFU-4l(arge)) (H(2)-BTDD=bis(1H-1,2,3-triazolo[4,5-b],[4',5'-i])dibenzo[1,4]dioxin), has been synthesized using ZnCl(2) and H(2)-BTDD in N,N-dimethylformamide as a solvent. MFU-4l represents the first example of MFU-4-type frameworks featuring large pore apertures of 9.1 Å. Here, MFU-4l serves as a reference compound to evaluate the origin of unique and specific gas-sorption properties of MFU-4, reported previously. The latter framework features narrow-sized pores of 2.5 Å that allow passage of sufficiently small molecules only (such as hydrogen or water), whereas molecules with larger kinetic diameters (e.…
A tris-oxovanadium pyrogallate complex: synthesis, structure, and magnetic and electronic properties
2021
International audience; With the aim of identifying new cation-phenolate complexes, we herein investigated the reactivity of pyrogallol (H(3)pgal) with vanadium salts. A trimetallic anionic complex was identified, and found to be formed under a broad set of reaction conditions. This complex, with the formula V3O3(pgal)(3)(3-), consists of three oxovanadium(iv) units connected together by three pyrogallate ligands to afford a bowl-shaped species presenting a pseudo 3-fold symmetry axis. Its crystal structure is reported, as well as its characterisation by a broad set of techniques, including powder X-ray diffraction, thermogravimetric analysis, infrared and Raman spectroscopy, and solid stat…
Coordination Driven Capture of Nicotine Inside a Mesoporous MOF.
2017
Metal organic frameworks (MOFs) are a wide class of crystalline porous polymers studied in many fields, ranging from catalysis to gas storage. In the past few years, MOFs have been studied for the encapsulation of organic or organometallic molecules and for the development of potential drug carriers. Here, we report on the study of two structurally-related mesoporous Cu-MOFs, namely PCN-6 and PCN-6′ (PCN stands for Porous Coordination Network), for nicotine trapping. Nicotine is a well-known alkaloid liquid molecule at room temperature, whose crystalline structure is still unknown. In this work, the loading process was monitored by electron ionization mass spectrometry by using a direct ins…
Ti-based robust MOFs in the combined photocatalytic degradation of emerging organic contaminants.
2022
Photocatalysis process is a promising technology for environmental remediation. In the continuous search of new heterogeneous photocatalysts, metal–organic frameworks (MOFs) have recently emerged as a new type of photoactive materials for water remediation. Particularly, titaniumbased MOFs (Ti-MOFs) are considered one of the most appealing subclass of MOFs due to their promising optoelectronic and photocatalytic properties, high chemical stability, and unique structural features. However, considering the limited information of the reported studies, it is a hard task to determine if real-world water treatment is attainable using Ti-MOF photocatalysts. In this paper, via a screening with seve…
Biodesign for conformational adaptability and guest recognition in crystalline frameworks
2021
La presente tesis doctoral ha sido realizada como compendio de publicaciones y lleva por título “Biodiseño en adaptabilidad conformacional y reconocimiento de huéspedes en estructuras cristalinas” (Biodesign for conformational adaptability and guest recognition in crystalline frameworks). Se encuentra dividida en cuatro capítulos con unas conclusiones finales y resumen en castellano. El primer capítulo se trata de una introducción a las redes metal-orgánicas (MOFs) basados en materiales biológicos, tanto su diseño a partir de éstos, como algunas de sus aplicaciones más notables. Inicialmente se habla del origen de este tipo de sistemas, que radica en la necesidad que tenían los químicos hac…
Stimuli-responsive magnetic coordination polymers: from crystals to nanoparticles
2013
El trabajo descrito en esta tesis se enmarca en el ámbito de los polímeros de coordinación (PC). Estos sistemas representan un área importante dentro de la Química de los Materiales, siendo principalmente interesantes sus aplicaciones en catálisis, electrónica y óptica. Su origen data de principios de los años 60, donde se produjo la primera revisión de estructuras de compuestos inorgánicos que formaban cadenas.1 Los PC están formados por ligandos orgánicos y metales enlazados por enlaces de coordinación que se extienden infinitamente en 1, 2 o 3 dimensiones. En cuanto a su versatilidad química, las estructuras y propiedades varían en función de los metales o ligandos utilizados. Así pues, …
Exploring chemical complexity in group IV reticular solids
2022
Esta tesis aborda el reto de ampliar las herramientas sintéticas disponibles para aumentar la complejidad química de los materiales reticulares basados en metales del grupo IV, dirigiéndose tanto a la parte orgánica como a la inorgánica de estos materiales porosos e híbridos. El capítulo 1 ofrece una visión del aumento de la complejidad química en los sólidos reticulares, que proporciona un contexto general a los resultados desarrollados durante esta tesis. A continuación, la introducción de la variación química en los conectores orgánicos se describe en los capítulos 2, 3 y 4, mientras que la transformación química de los nodos inorgánicos se introduce en el capítulo 5. Todo el trabajo des…
Water Adsorption in Flexible Gallium-Based MIL-53 Metal–Organic Framework
2014
Understanding the adsorption of water in metal–organic frameworks (MOF), and particularly in soft porous crystals, is a crucial prerequisite before considering MOFs for industrial applications. We report here a joint experimental and theoretical study on the behavior of a gallium-based breathing MOF, Ga-MIL-53, upon water adsorption. By looking at the energetics and thermodynamics of Ga-MIL-53, we demonstrate why it behaves differently from its sibling Al-MIL-53, showing a different phase at room temperature (a nonporous phase) and the presence of a hydrated narrow-pore structure at gas saturation pressure. Moreover, we present a complete water vapor pressure vs temperature phase diagram of…