Search results for " FRAMEWORK"
showing 10 items of 893 documents
Breathing-Dependent Redox Activity in a Tetrathiafulvalene-Based Metal–Organic Framework
2018
"Breathing" metal-organic frameworks (MOFs) that involve changes in their structural and physical properties upon an external stimulus are an interesting class of crystalline materials due to their range of potential applications including chemical sensors. The addition of redox activity opens up a new pathway for multifunctional "breathing" frameworks. Herein, we report the continuous breathing behavior of a tetrathiafulvalene (TTF)-based MOF, namely MUV-2, showing a reversible swelling (up to ca. 40% of the volume cell) upon solvent adsorption. Importantly, the planarity of the TTF linkers is influenced by the breathing behavior of the MOF, directly impacting on its electrochemical proper…
Present and Perspectives of Photoactive Porous Composites Based on Semiconductor Nanocrystals and Metal-Organic Frameworks
2021
This review focuses on the recent developments in synthesis, properties, and applications of a relatively new family of photoactive porous composites, integrated by metal halide perovskite (MHP) nanocrystals and metal-organic frameworks (MOFs). The synergy between the two systems has led to materials (MHP@MOF composites) with new functionalities along with improved properties and phase stability, thus broadening their applications in multiple areas of research such as sensing, light-harvesting solar cells, light-emitting device technology, encryption, and photocatalysis. The state of the art, recent progress, and most promising routes for future research on these photoactive porous composit…
Coordination networks incorporating halogen-bond donor sites and azobenzene groups
2016
Two Zn coordination networks, {[Zn(1)(Py)2]2(2-propanol)}n (3) and {[Zn(1)2(Bipy)2](DMF)2}n (4), incorporating halogen-bond (XB) donor sites and azobenzene groups have been synthesized and fully characterized. Obtaining 3 and 4 confirms that it is possible to use a ligand wherein its coordination bond acceptor sites and XB donor sites are on the same molecular scaffold (i.e., an aromatic ring) without interfering with each other. We demonstrate that XBs play a fundamental role in the architectures and properties of the obtained coordination networks. In 3, XBs promote the formation of 2D supramolecular layers, which, by overlapping each other, allow the incorporation of 2-propanol as a gues…
The Determinants of the Volatility of Fiscal Policy Discretion
2014
We investigate the determinants of the volatility of fiscal policy discretion. Using a linear dynamic panel dataset model for 104 countries from 1980 to 2006 and a system-GMM estimator,we find that more government instability, less democracy and presidentialist systems increase the volatility of the discretionary component of fiscal policy. Additionally, we show that countries with a larger size, a smaller degree of financial openness, and a stable exchange rate system are more insured against the uncertainty about the conduct of fiscal policy. Our results are robust to various regional dummy variables, diferent sub-sets of countries and the presence of high inflation and crisis episodes.
Enantiospecific Response in Cross-Polarization Solid-State Nuclear Magnetic Resonance of Optically Active Metal Organic Frameworks.
2020
We report herein on a NMR-based enantiospecific response for a family of optically active metal-organic frameworks. Cross-polarization of the 1H-13C couple was performed, and the intensities of the 13C nuclei NMR signals were measured to be different for the two enantiomers. In a direct-pulse experiment, which prevents cross-polarization, the intensity difference of the 13C NMR signals of the two nanostructured enantiomers vanished. This result is due to changes of the nuclear spin relaxation times due to the electron spin spatial asymmetry induced by chemical bond polarization involving a chiral center. These experiments put forward on firm ground that the chiral-induced spin selectivity e…
Stimuli-responsive hybrid materials: breathing in magnetic layered double hydroxides induced by a thermoresponsive molecule
2014
[EN] A hybrid magnetic multilayer material of micrometric size, with highly crystalline hexagonal crystals consisting of CoAl-LDH ferromagnetic layers intercalated with thermoresponsive 4-(4-anilinophenylazo)benzenesulfonate (AO5) molecules diluted (ratio 9 : 1) with a flexible sodium dodecylsulphate (SDS) surfactant has been obtained. The resulting material exhibits thermochromism attributable to the isomerization between the azo (prevalent at room temperature) and the hydrazone (favoured at higher temperatures) tautomers, leading to a thermomechanical response. In fact, these crystals exhibited thermally induced motion triggering remarkable changes in the crystal morphology and volume. In…
Life satisfaction and the mediating role of character strengths and gains in informal caregivers
2021
WHAT IS KNOWN ON THE SUBJECT?: The role of informal caregiver can have both negative and positive consequences for a person's well-being. The main theoretical framework for explaining these consequences is the stress process model, which considers contextual variables, stressors and mediating/moderating factors. The latter are psychosocial factors such as coping strategies, personal mastery, social support or beliefs and values which may influence caregiver well-being. The perception of gains in caregiving has also been proposed as a mediating variable since it may act as a coping strategy. However, few studies have examined values and perceived gains as mediating variables with life satisf…
Goals and Principles of Providers Working with People Experiencing Homelessness: A Comparison Between Housing First and Traditional Staircase Service…
2019
Contains fulltext : 207157.pdf (Publisher’s version ) (Open Access) The implementation and adaptation of the Housing First (HF) model represented profound changes the structure and delivery, goals, and principles of homeless services. These features of homeless services directly influence providers, their work performance and the clients' outcomes. The present research, conducted in eight European countries, investigated how social providers working in HF or TS (Traditional Staircase) describe and conceptualize the goals and the principles of their services. Data were collected through 29 focus group discussions involving 121 providers. The results showed that HF and TS had similar and diff…
Evidence-based development of school-based and family-involved prevention of overweight across Europe: The ENERGY-project's design and conceptual fra…
2010
Background There is an urgent need for more carefully developed public health measures in order to curb the obesity epidemic among youth. The overall aim of the "EuropeaN Energy balance Research to prevent excessive weight Gain among Youth" (ENERGY)-project is the development and formative evaluation of a theory-informed and evidence-based multi-component school-based and family-involved intervention program ready to be implemented and evaluated for effectiveness across Europe. This program aims at promoting the adoption or continuation of health behaviors that contribute to a healthy energy balance among school-aged children. Earlier studies have indicated that school and family environmen…
Relativistic corrections and unitary equivalence in elastic electron deuteron scattering.
1993
The role of unitary equivalence of relativistic corrections in elastic electron deutron scattering is studied, starting from a class of approximately, unitarily equivalent Hamiltonians and using consistent charge density operators. The connection of various formal approaches for deriving the relativistic corrections to wave functions and operators are discussed in detail. For reasons of simplicity, we have chosen a pure one-pion-exchange model and calculated the charge and quadrupole form factors of the deuteron. The numerical results show that the unitary equivalence holds at small momentum transfers, but breaks down rather soon with increasing momentum transfers (\ensuremath{\lesssim}5 ${…