Size- and Shape-Selective Isostructural Microporous Metal–Organic Frameworks with Different Effective Aperture Sizes

Synthesis of a Chiral 3,6T22-Zn-MOF with a T-Shaped Bifunctional Pyrazole-Isophthalate Ligand Following the Principles of the Supramolecular Building Layer Approach

The metal–organic framework (MOF) [Zn(Isa-az-tmpz)]·~1–1.5 DMF with the novel T-shaped bifunctional linker 5-(2-(1,3,5-trimethyl-1H-pyrazol-4-yl)azo)isophthalate (Isa-az-tmpz) was obtained as a conglomerate of crystals with varying degrees of enantiomeric excess in the chiral tetragonal space groups P4₃2₁2 or P4₁2₁2. A topological analysis of the compound resulted in the rare 3,6T22-topology, deviating from the expected rtl-topology, which has been found before in pyrazolate-isophthalate-functionalized MOFs using the supramolecular building layer (SBL) approach. 3,6T22-[Zn(Isa-az-tmpz)]·~1–1.5 DMF is a potentially porous, three-dimensional structure with DMF molecules included in the corrugated channels along the a and b-axis of the as synthesized material. The small trigonal cross-section of about 6 × 4 Å (considering the van der Waals surface) prevents the access of N₂ and Ar under cryogenic conditions. After activation, only smaller H₂ (at 87 K) and CO₂ (at 195 K) are allowed for gas uptakes of 2 mmol g^–1 and 5.4 mmol g^–1, respectively, in the ultramicroporous material, for which a BET surface area of 496 m²·g^–1 was calculated from CO₂ adsorption. Thermogravimetric analysis of the compound shows a thermal stability of up to 400 °C.

Effect of pyridyl donors from organic ligands versus metalloligands on material design

This review illustrates designs and structures of various coordination frameworks constructed using assorted organic ligands and metalloligands offering pyridyl donors to evaluate the impact of flexibility versus rigidity on material design.

Electrochemiluminescence immunoassay for the N-terminal pro-B-type natriuretic peptide based on resonance energy transfer between a self-enhanced luminophore composed of silver nanocubes on gold nanoparticles and a metal-organic framework of type MIL-125

The N-terminal pro-B-type natriuretic peptide (NT-proBNP) is a marker of heart failure. A novel sandwich type electrochemiluminescence (ECL) immunoassay is described for the NT-proBNP. The method is based on ECL resonance energy transfer (RET) between silver nanocubes that were covered with semicarbazide-modified gold nanoparticles (AgNC-sem@AuNPs) as the donor, and a Ti(IV)-based metal-organic framework of type MIL-125 as the acceptor. The ECL signal was strongly amplified by increasing the luminous efficiency. ECL-RET occurs due to the partial overlap between the ECL emission of the AgNC-sem@AuNPs (emission wavelength at 470 nm to 900 nm) and the visible absorption spectrum of MIL-125 (absorption wavelength at 406 nm to 900 nm). This results in the quenching of ECL. The AgNC-sem@AuNPs were placed on the electrode. The antibody was immobilized on AgNC-sem@AuNPs via Au-NH₂ bond, and MIL-125 was utilized as a label for the secondary antibody. The assay works in the 0.25 pg mL^-1 to 100 ng mL^-1 concentration range and has a 0.11 pg mL^-1 lower detection limit (at S/N = 3). Graphical abstract Schematic representation of self-enhanced luminescence mechanism (semicarbazide (Sem) as co-reaction accelerator) and Electrochemiluminescence resonance energy transfer (ECL-RET): silver nanocubes (AgNCs) as the energy donor and MIL-125 as the energy acceptor.

A microporous Cu2+MOF based on a pyridyl isophthalic acid Schiff base ligand with high CO2uptake

A new microporous Cu²⁺MOF is reported containing a pyridyl-isophthalic acid Schiff base ligand which exhibits a significant BET area and high CO₂sorptbion capacity.

Hydrogen physisorption in ionic solid compounds with exposed metal cations at room temperature

Phenol- and phloroglucinol-based ionic solid complexes for room temperature hydrogen storage via physisorption.

Amide and N-oxide functionalization of T-shaped ligands for isoreticular MOFs with giant enhancements in CO2 separation

N-Oxidization of a T-shaped ligand has proven to be an effective way to enhance CO₂ adsorption enthalpy and selectivity in porous MOFs for the first time.

Novel (3,4,6)-connected metal-organic framework with high stability and gas-uptake capability

A microporous and noninterpenetrated metal-organic framework [Cu(3)(L)(2)(DABCO)(H(2)O)]·15H(2)O·9DMF (1) has been synthesized using two different ligands, [1,1':3',1″-terphenyl]-4,4″,5'-tricarboxylic acid (H(3)L) and 1,4-diazabicyclo[2.2.2]octane (DABCO). As revealed by variable-temperature powder X-ray diffraction (VT-PXRD) measurements, N,N'-ditopic DABCO plays an important role for stabilization of the Cu-L framework. The three-dimensional framework of 1 exhibits high stability and excellent adsorption capacity for H(2) (54.3 mg g(-1) at 77 K and 20 bar), CO(2) (871 mg g(-1) at 298 K and 20 bar), CH(4) (116.7 mg g(-1), 99 cm(3) (STP) cm(-3) at 298 K and 20 bar), and n-pentane (686 mg g(-1) at 298 K and 1 bar). Interestingly, the excellent selectivity toward CO(2) over N(2) at ambient temperature (273 and 298 K) and 1 bar makes complex 1 possess practical application in gas separation and purification.