Yingxiang Ye

Separating a propylene/propane (C3H6/C3H8) mixture is essential in the chemical industry for producing polymer-grade propylene. Emerging adsorbent-based separation methods are an energy-efficient alternative, particularly molecular sieving, offering excellent selectivity and purity by excluding undesired gases. However, precise pore structure and adsorption sites are required for achieving complete exclusion, posing a daunting synthetic challenge. Here, we demonstrate sieving separation of C3H6/C3H8 mixtures using the customized ultra-microporous anion-pillared MOF, TaOFFIVE-1-Ni (1 = pyrazine) via precise control of aperture size and binding sites. The dynamic, narrow pore window allows for the selective passage of C3H6, exhibiting excellent C3H6 uptake of 72.7 cm3 cm–3 with rapid adsorption kinetics while blocking slightly larger C3H8 (5.9 cm3 cm–3) under ambient conditions. Computational simulations revealed that electronegative fluorine sites provide strong binding interactions, thereby enhancing adsorption capacity. Dynamic breakthrough experiments further confirm the excellent potential of TaOFFIVE-1-Ni, delivering high-purity propylene (≥95.5%) from binary propylene/propane mixtures. Additionally, the high thermal stability, stability in aqueous acidic and basic media, and g-scale synthesizability of this MOF make it well-suited for long-term use in industrial propylene purification.

In metal-organic frameworks, the scaffold serves as a passive host matrix, relying primarily on the assembly of prefunctionalized ligands to define the pore environment. Constructing cooperative binding pockets via this approach is often impeded by synthetic complexity and the steric hindrance of bulky functional groups. Herein, we present the design of two robust, tertiary amine-embedded cyclen-based ligands: one tetratopic and the other T-shaped tritopic. The two ligands were used to synthesize three isostructural, highly porous Zr-metal-macrocyclic frameworks (MMCFs), denoted as MMCF-5, MMCF-7-AcOH, and MMCF-7-AA. We highlight that the tritopic ligand enabled the framework as a reactive matrix through a strategy termed in situ reticular editing (ISRE). Utilizing SO₂ as a probe to interrogate the pore environment, MMCF-7-AA exhibits an exceptional capacity of 12.5 mmol g^-1 at 1 bar and 1.43 mmol g^-1 at 2500 ppm. These metrics not only position it among the top-performing adsorbents at low partial pressures but, more importantly, corroborate the successful construction of the cooperative binding sites. We then elucidated this distinct SO₂ sorption behavior through X-ray crystallography, density functional theory (DFT) calculations, and in situ diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy. This work establishes ISRE as a versatile blueprint for pore editing, offering a feasible pathway to evolve sophisticated chemical environments by harnessing simple precursor scaffolds as reactive matrices.

Solvent-induced conformational changes in organic building blocks enable effective regulation of the emission wavelength of a pair of hydrogen-bonded organic frameworks.

Aluminum products have a wide range of applications in daily life, but excessive accumulation of aluminum (Al³⁺) ions causes diseases and affects human health. The accurate detection of Al³⁺ ions is crucial for preventing their accumulation and mitigating adverse effects on human health. Herein, a luminescent metal-organic framework (MOF), FJU-40-NH₂, has been designed for selective aluminum ion (Al³⁺) detection with a significantly enhanced fluorescence response. This designed FJU-40-NH₂ incorporates a π-conjugated aromatic system as luminescent units and abundant free amino groups as potential binding sites, endowing it with an exceptional ability to selectively sense Al³⁺ ions. This host-guest interaction results in a significant fluorescence enhancement, making the FJU-40-NH₂ an ideal "turn-on" sensor for Al³⁺ ions with high sensitivity, selectivity, and stability. This substantial fluorescence enhancement is due to the efficient electron transfer after the interaction between Al³⁺ ions and the amino groups of FJU-40-NH₂. More importantly, this "turn-on" fluorescent sensor has been successfully utilized for the analysis of Al³⁺ ion content in real food samples, yielding recoveries ranging from 92.2 to 105.0%, confirming its potential applications in practical environmental and food safety monitoring.