Synthesis and real-time monitoring of the morphological evolution of luminescent Eu(TCPP) MOFs

Real-time acquisition of the morphological information of nanomaterials is crucial to achieving morphological controllable synthesis, albeit being challenging. A novel device was designed, which integrated dielectric barrier discharge (DBD) plasma synthesis and simultaneous in situ spectral monitoring of the formation of metal-organic frameworks (MOFs). Important dynamic luminescence behaviors such as coordination induced emission (CIE), antenna effect (AE), and red-blue shift were continuously captured to reveal the spectral emission mechanism and energy transfer progress and verify the correlation with the morphological evolution of the MOFs. The prediction and control of morphology were successfully achieved with Eu(TCPP) as a model MOF. The proposed method will shed new light on exploring the spectral emission mechanism, energy conversion and in situ morphology monitoring of other luminescent materials.

Syntheses directed by ionic liquids: structures and properties of six novel lanthanide 1,3,5-benzenetrisbenzoate frameworks

Reactions of lanthanide nitrate, 1,3,5-benzenetrisbnzoic acid (H3BTB) and [RMI]Br ionic liquids (RMI = 1-alkyl-3-methylimidazolium; R = ethyl, propyl or butyl), gave rise to six novel lanthanide–organic frameworks (LOFs) [Ln(BTB)H2O], where Ln = Nd 1, Sm 2, Gd 3, Dy 4, Ho 5 and Er 6. These compounds have been characterized by elemental analysis, IR spectra, thermogravimetric analysis, single-crystal and powder X-ray diffraction. Compounds 1–6 are isostructural and consist of infinite rod-shaped lanthanide-carboxylate building units, which are further bridged by trigonal-planar BTB ligands to give non-interpenetrated open 3D frameworks. The results of variable-temperature magnetic studies have shown that the magnetic interaction between the Ln(III) ions in 3, 5 and 6 is mainly due to antiferromagnetic coupling as well as the depopulation of the Stark levels.

A series of microporous and robust Ln-MOFs showing luminescence properties and catalytic performances towards Knoevenagel reactions

A series of microporous Ln(III)-based metal-organic frameworks (1-Ln) have been hydrothermally synthesized using 4,4',4''-nitrilotribenzoic acid (H₃NTB). Single crystal X-ray diffraction analyses show that 1-Ln are isostructural and have 3D porous frameworks with remarkable stability and permanent porosity for Ar and CO₂ adsorption. In addition, 1-Ln exhibit diverse photoluminescence emissions depending on the nature of lanthanide ions. More importantly, 1-Ln are further studied in the Knoevenagel reactions of benzaldehyde derivatives and malononitrile under solvent-free conditions, and it is found that 1-Tb shows the best catalytic activities (yields up to 99%), providing a unique example to differentiate the roles of Ln ions within the frameworks in catalyzing Knoevenagel reactions.

A Dy6-cluster-based fcu-MOF with efficient separation of C2H2/C2H4 and selective adsorption of benzene

A stable Dy-MOF was constructed based on hexanuclear clusters, and contains F-decorated pores and reveals separation performance for C₂H₂/CH₄, C₂H₄/CH₄ and C₂H₂/C₂H₄ and selective adsorption of benzene/cyclohexane and benzene/toluene.

A new honeycomb metal–carboxylate-tetrazolate framework with multiple functions for CO2 conversion and selective capture of C2H2, CO2 and benzene

A stable Cd-MOF was built by a carboxylate-tetrazolate ligand, which contains hexagonal channels and reveals multiple functions including separation of CO₂/CH₄, C₂H₂/CO₂, C₂H₂/CH₄ and benzene/cyclohexane, and catalytic conversion of CO₂ with epoxides.

Synthesis of Chiral Labtb and Visualization of Its Enantiomeric Excess by Induced Circular Dichroism Imaging

Crystalline particles of a microporous, robust, and chiral metal-organic framework (MOF) were synthesized and their enantiomer excess (ee) was visualized for each microparticle by CD imaging. Labtb, a thermally and chemically robust MOF, was employed in this study because it shows a chiral space group. Although Labtb has been obtained as a racemic conglomerate, enantioselective synthesis of Labtb was achieved via a chiral precursor complex consisting of lanthanum and homochiral phenylalanine. Methyl orange (MO) was introduced into the micropores of chiral Labtb, which showed a strong induced CD signal for the absorption band of MO chromophores. High ee of the chiral Labtb was revealed by microscopic CD observation at the particle-level. This result provides a facile way to obtain a robust MOF that has chiral nanospace.

Acidity and Cd2+ fluorescent sensing and selective CO2 adsorption by a water-stable Eu-MOF

A new luminescent Eu-MOF from an amino-group modified tetracarboxylic acid ligand was designed, which could perform as an efficient pH acidity and Cd²⁺ PL sensor and CO₂ selector.

Selective Adsorption and Separation of Xylene Isomers and Benzene/Cyclohexane with Microporous Organic Polymers POP-1

The separation of chemical substances with analogous chemical structures and physical properties remains a great challenge. In this work, triptycene-like microporous organic polymers (MOPs), POP-1, was synthesized via choosing 1,4-dimethoxybenzene (DMB) and triptycene as external cross-linkers and building blocks, respectively, and POP-1 was employed to separate xylene isomers and benzene (Bz)/cyclohexane (Cy). Results show that POP-1 has a higher uptake for m-xylene (0.29 g/g) and Bz (1.02 g/g); more intriguingly, their complete separation can be realized within 0.6 min using a column packed with POP-1. The interaction between POP-1 networks and adsorbates was also investigated using theoretical (density functional theory together with noncovalent interaction analysis) and experimental (inverse gas chromatography) approaches. Especially, both results present a good agreement, that is, weak interactions such as CH/π interactions play a dominant role in defining the separation performance of POP-1 for xylene isomers and Bz/Cy mixtures. Our findings suggest that MOPs may open up a new route for separating the chemicals that are similar in structure and size.

A highly sensitive near-infrared luminescent metal-organic framework thermometer in the physiological range

A near-infrared luminescent metal-organic framework Nd0.866Yb0.134BTB was developed as a self-calibrated thermometer in the physiological range. Its features include high sensitivity and resolution, and good biocompatibility, making such a material useful for biomedical applications.

A porous lanthanide metal–organic framework based on a flexible cyclotriphosphazene-functionalized hexacarboxylate exhibiting selective gas adsorption

This work presents a rare example of a permanently porous Ln-MOF based on a flexible hexacarboxylate exhibiting selective gas adsorption.

Two chelating-amino-functionalized lanthanide metal–organic frameworks for adsorption and catalysis

The chelating-amine groups lie in channels that enhance CO₂ and dye adsorptions. The LnMOFs also show good catalytic activities.

A water-stable lanthanide-organic framework as a recyclable luminescent probe for detecting pollutant phosphorus anions

An Eu-MOF can selectively detect PO₄³⁻ and it represents the first example of regenerable MOF-based luminescent probes for detecting PO₄³⁻.

π-System based coordination polymer hollow nanospheres for the selective sensing of aromatic nitro explosive compounds

π-System embedded coordination polymer hollow nanospheres were synthesized, which showed a good sensing performance for the detection of aromatic explosive nitro-compounds.

Lanthanide contraction effects on the structures, thermostabilities, and CO2 adsorption and separation behaviors of isostructural lanthanide–organic frameworks

A systematic investigation of the CO₂ adsorption and separation behaviours of fourteen isostructural lanthanide–organic frameworks of lanthanide benzenetricarboxylate is executed.

Ionic liquid directed syntheses of water-stable Eu– and Tb–organic-frameworks for aqueous-phase detection of nitroaromatic explosives

Ionic liquid directed syntheses of water-stable Eu– and Tb–organic-frameworks for aqueous-phase detection of nitroaromatic explosives.