Search results for "IC framework"
showing 10 items of 268 documents
Nanoporosity, Inclusion Chemistry, and Spin Crossover in Orthogonally Interlocked Two-Dimensional Metal-Organic Frameworks
2015
[Fe(tvp)(2)(NCS)(2)] (1) (tvp=trans-(4,4-vinylenedipyridine)) consists of two independent perpendicular stacks of mutually interpenetrated two-dimensional grids. This uncommon supramolecular conformation defines square-sectional nanochannels (diagonal approximate to 2.2nm) in which inclusion molecules are located. The guest-loaded framework 1@guest displays complete thermal spin-crossover (SCO) behavior with the characteristic temperature T-1/2 dependent on the guest molecule, whereas the guest-free species 1 is paramagnetic whatever the temperature. For the benzene-guest derivatives, the characteristic SCO temperature T-1/2 decreases as the Hammet sigma(p) parameter increases. In general, …
Binuclear Cu2+ complex mediated discrimination between L-glutamate and L-aspartate in water.
2005
L-Glutamate and L-aspartate selectivity is achieved by the action of two Cu2+ metal ions rightly disposed in a cyclophanetype macrocyclic framework; electrochemical sensing of glutamate has been achieved by adsorption of the copper complexes on graphite electrodes. Verdejo Viu, Begoña, Begona.Verdejo@uv.es ; Domenech Carbo, Antonio, Antonio.Domenech@uv.es ; Jimenez Garcia, Hermas Rafael, Hermas.Jimenez@uv.es ; Soriano Soto, Concepción, Concepcion.Soriano@uv.es ; Garcia-España Monsonis, Enrique, Enrique.Garcia-Es@uv.es
Peptide Metal–Organic Frameworks for Enantioselective Separation of Chiral Drugs
2017
We report the ability of a chiral Cu(II) 3D MOF based on the tripeptide Gly-L-His-Gly (GHG) for the enantioselective separation of metamphetamine and ephedrine. Monte Carlo simulations suggest that chiral recognition is linked to preferential binding of one of the enantiomers as result of either stronger or additional H-bonds with the framework that lead to energetically more stable diastereomeric adducts. Solid phase extraction (SPE) of a racemic mixture by using Cu(GHG) as extractive phase permits isolating more than 50% of the (+)-ephedrine enantiomer as target compound in only four minutes. To the best of our knowledge, this represents the first example of a MOF capable of separating ch…
Lanthanide Discrimination with Hydroxyl-Decorated Flexible Metal–Organic Frameworks
2018
We report two new highly crystalline metal-organic frameworks (MOFs), derived from the natural amino acids serine (1) and threonine (2), featuring hexagonal channels densely decorated with hydroxyl groups belonging to the amino acid residues. Both 1 and 2 are capable of discriminating, via solid-phase extraction, a mixture of selected chloride salts of lanthanides on the basis of their size, chemical affinity, and/or the flexibility of the network. In addition, this discrimination follows a completely different trend for 1 and 2 because of the different locations of the hydroxyl groups in each compound, which is evocative of steric complementarity between the substrate and receptor. Last bu…
Tunable Spin-Crossover Behavior of the Hofmann-like Network {Fe(bpac)[Pt(CN) 4 ]} through Host-Guest Chemistry
2013
A study of the spin-crossover (SCO) behavior of the tridimensional porous coordination polymer {Fe(bpac)[Pt(CN)4]} (bpac=bis(4-pyridyl) acetylene) on adsorption of different mono- and polyhalobenzene guest molecules is presented. The resolution of the crystal structure of {Fe(bpac)[Pt(CN) 4]}A?G (G=1,2,4-trichlorobenzene) shows preferential guest sites establishing I?A?A?A?I? stacking interactions with the host framework. These host-guest interactions may explain the relationship between the modification of the SCO behavior and both the chemical nature of the guest molecule (electronic factors) and the number of adsorbed molecules (steric factors). Copyright © 2013 WILEY-VCH Verlag GmbH & …
Polyoxometalate Metal–Organic Frameworks: Keggin Clusters Encapsulated into Silver-Triazole Nanocages and Open Frameworks with Supercapacitor Perform…
2019
To investigate the relationship between the structures of polyoxometalate host–guest materials and their energy-storage performance, three novel polyoxometalate-based metal–organic compounds, [Ag10...
Metal-functionalized covalent organic frameworks as precursors of supercapacitive porous N-doped graphene
2017
Covalent Organic Frameworks (COFs) based on polyimine with several metal ions (FeIII, CoII and NiII) adsorbed into their cavities have shown the ability to generate N-doped porous graphene from their pyrolysis under controlled conditions. These highly corrugated and porous graphene sheets exhibit high values of specific capacitance, which make them useful as electrode materials for supercapacitors.
Metal–organic framework technologies for water remediation: towards a sustainable ecosystem
2018
Having access to clean water is a mandatory requirement for the proper development of living beings. So, addressing the removal of contaminants from aquatic systems should be a priority research topic in order to restore ecosystem balance and secure a more sustainable future. The fascinating structures and striking physical properties of metal–organic frameworks (MOFs) have revealed them as excellent platforms for the removal of harmful species from water. In this review, we have focused our attention on critically highlighting the latest developments achieved in the adsorptive removal of inorganic – metal cations, inorganic acids, oxyanions/cations, nuclear wastes and other inorganic anion…
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…