Shaping the Water-Harvesting Behavior of Metal-Organic Frameworks Aided by Fine-Tuned GPT Models.

We construct a data set of metal-organic framework (MOF) linkers and employ a fine-tuned GPT assistant to propose MOF linker designs by mutating and modifying the existing linker structures. This strategy allows the GPT model to learn the intricate language of chemistry in molecular representations, thereby achieving an enhanced accuracy in generating linker structures compared with its base models. Aiming to highlight the significance of linker design strategies in advancing the discovery of water-harvesting MOFs, we conducted a systematic MOF variant expansion upon state-of-the-art MOF-303 utilizing a multidimensional approach that integrates linker extension with multivariate tuning strategies. We synthesized a series of isoreticular aluminum MOFs, termed Long-Arm MOFs (LAMOF-1 to LAMOF-10), featuring linkers that bear various combinations of heteroatoms in their five-membered ring moiety, replacing pyrazole with either thiophene, furan, or thiazole rings or a combination of two. Beyond their consistent and robust architecture, as demonstrated by permanent porosity and thermal stability, the LAMOF series offers a generalizable synthesis strategy. Importantly, these 10 LAMOFs establish new benchmarks for water uptake (up to 0.64 g g-1) and operational humidity ranges (between 13 and 53%), thereby expanding the diversity of water-harvesting MOFs.

Fluorescent supramolecular hydrogels self-assembled from tetraphenylethene (TPE)/single amino acid conjugates.

Herein, we report the synthesis of simple TPE/single amino acid conjugates, TPE-Ser and TPE-Asp with side-chains featuring functional groups that may provide an additional hydrogen bonding network for hydrogelation in aqueous medium. TPE-Ser, which has the lowest molecular weight, containing hydroxyl groups undergoes self-assembly into supramolecular hydrogels under physiological pH conditions. TPE-Asp with a carboxylic group side chain undergoes the self-assembly and hydrogelation processes under slightly acidic conditions (pH = 6.0). UV-vis, IR, PL and rheological studies clearly indicate the formation, stability and fluorescence properties of TPE-amino acid hydrogels. TEM micrographs of the hydrogels indicate that the compounds are self-assembled into a nanosheet morphology with random size and shape. Further, in vitro analysis of TPE-Ser and TPE-Asp with 3A6 cells shows that the compounds exhibit unique fluorescence signals in microcellular environments thus making them suitable candidates for bioimaging applications. Overall, these findings highlight the importance of the structure-hydrogelation relationship and provide new insights into the design of single amino-acid-based supramolecular hydrogels.

Expanding the Ligand Framework Diversity of Carbodicarbenes and Direct Detection of Boron Activation in the Methylation of Amines with CO2.

A simple and convergent synthetic strategy used to increase the diversity of the carbodicarbene ligand framework through incorporation of unsymmetrical pendant groups is reported. Structural analysis and spectroscopic studies of ligands and their Rh complexes are reported. Reactivity studies reveal carbodicarbenes as competent organocatalysts for amine methylation using CO2 as a synthon. A unique BH-activated boron-carbodicarbene complex was isolated as a reaction intermediate, providing mechanistic insight into the CO2 functionalization process.