Search results for "frameworks"

Synergetic effect of host-guest chemistry and spin crossover in 3D Hofmann-like metal-organic frameworks [Fe(bpac)M(CN)4] (M=Pt, Pd, Ni).

2012

The synthesis and characterization of a series of three-dimensional (3D) Hofmann-like clathrate porous metal-organic framework (MOF) materials [Fe(bpac)M(CN) 4] (M=Pt, Pd, and Ni; bpac=bis(4-pyridyl)acetylene) that exhibit spin-crossover behavior is reported. The rigid bpac ligand is longer than the previously used azopyridine and pyrazine and has been selected with the aim to improve both the spin-crossover properties and the porosity of the corresponding porous coordination polymers (PCPs). The 3D network is composed of successive {Fe[M(CN) 4]} n planar layers bridged by the bis-monodentate bpac ligand linked in the apical positions of the iron center. The large void between the layers, w…

Confined crystallization of a HKUST-1 metal–organic framework within mesostructured silica with enhanced structural resistance towards water

2017

A HKUST-1 metal–organic framework was crystallized in the NH2-modified mesostructured silica FDU-12 in order to improve its structural stability upon water exposure. In-depth structural characterization studies of the designed composite confirmed successful formation of the MOF phase within the ordered spherical mesopores of the silica matrix. In spite of the confinement within the cavities, MOF exhibits full accessibility for the adsorbed gas molecules. In contrast to the bulk HKUST-1, which undergoes slow phase transition in a humid environment, the structural integrity of the HKUST-1 in the humid-protective matrix remains unchanged even after immersion and stirring in water at elevated t…

Highly stable and porous porphyrin-based zirconium and hafnium phosphonates – electron crystallography as an important tool for structure elucidation

2018

The Ni-metallated porphyrin-based tetraphosphonic acid (Ni-tetra(4-phosphonophenyl)porphyrin, Ni-H8TPPP) was used for the synthesis of highly porous metal phosphonates containing the tetravalent cations Zr4+ and Hf4+. The compounds were thoroughly characterized regarding their sorption properties towards N2 and H2O as well as thermal and chemical stability. During the synthesis optimization the reaction time could be substantially decreased under stirring from 24 to 3 h in glass vials. M-CAU-30, [M2(Ni-H2TPPP)(OH/F)2]·H2O (M = Zr, Hf) shows exceptionally high specific surface areas for metal phosphonates of aBET = 1070 and 1030 m2 g-1 for Zr- and Hf-CAU-30, respectively, which are very clos…

Exploiting the Potential of New Coordination Frameworks for Technological Applications – from Temperature Sensing to Magnetic Storage

2022

Esta tesis es sobre el diseño, síntesis y caracterización de nuevos Polimeros de Coordinación (CPs), porosos o no, que muestran propiedades magnéticas y/o ópticas, para explotar su potencial en diversas aplicaciones tecnológicas. El diseño de estos materiales requiere una atención particular en la selección de los componentes básicos moleculares, los ligandos orgánicos y los nodos metálicos. Para construir CP con diferentes propiedades físicas, se han elegido derivados de carboxilato y anilato. En particular, el ácido 1,3,5-bencentricarboxílico (H3BTC, ácido trimésico), un ligando bioacompatible que permite construir polimeros organometálicos 3D robustos, y el 3,6-ditriazolil-2,5 -dihidroxi…

Chemical Engineering of Photoactivity in Heterometallic Titanium–Organic Frameworks by Metal Doping

2018

[EN] We report a new family of titanium-organic frameworks that enlarges the limited number of crystalline, porous materials available for this metal. They are chemically robust and can be prepared as single crystals at multi-gram scale from multiple precursors. Their heterometallic structure enables engineering of their photoactivity by metal doping rather than by linker functionalization. Compared to other methodologies based on the post-synthetic metallation of MOFs, our approach is well-fitted for controlling the positioning of dopants at an atomic level to gain more precise control over the band-gap and electronic properties of the porous solid. Changes in the band-gap are also rationa…

Humour as a symptom of research trends in translation studies

2017

This article is an overview of translation studies applied to the case of humour, divided into four parts, plus an extensive bibliography. The first part goes over humour translation as a relevant object of research and why it is worthy of more academic attention. Humour translation should not be dealt with or looked upon as a strange body within translation studies. Part two is an overview of key contributions to the field, from Spain and elsewhere, covering a considerable number of authors and theories. Part three focuses on promising areas of interest for researchers and illustrates how audiovisual translation is a good instance of dynamism within the field, connecting all this to the ri…

Synthesis of New Materials

2013

New Microbe Killers: Self-Assembled Silver(I) Coordination Polymers Driven by a Cagelike Aminophosphine

2019

New Ag(I) coordination polymers, formulated as [Ag(&micro

Recent progress in metal-organic frameworks (MOFs) for CO2 capture at different pressures

2022

Global climate change ensued by the rise in atmospheric CO2 levels is one of the greatest challenges our planet is facing today. This worldwide distress demands technologies that can contribute to our society toward “negative carbon emissions”. Carbon capture and storage (CCS) technologies are in in important role for capturing CO2 from existing emission sources, such as industrial and energy production point sources, before new more prominent modifications to the energy infrastructure can be implemented. Recently, alongside point source capture, direct air capture (DAC) processes have emerged as highly sought-after technologies that are able to capture CO2 from the ambient air. Alongside t…

A Crystalline 1D Dynamic Covalent Polymer

2022

The synthesis of crystalline one-dimensional polymers provides a fundamental understanding about the structure??? property relationship in polymeric materials and allows the preparation of materials with enhanced thermal, mechanical, and conducting properties. However, the synthesis of crystalline one-dimensional polymers remains a challenge because polymers tend to adopt amorphous or semicrystalline phases. Herein, we report the synthesis of a crystalline one-dimensional polymer in solution by dynamic covalent chemistry. The structure of the polymer has been unambiguously confirmed by microcrystal electron diffraction that together with charge transport studies and theoretical calculations…