Iodine Adsorption–Desorption-Induced Structural Transformation and Improved Ag + Turn-On Luminescent Sensing Performance of a Nonporous Eu(III) Metal–Organic Framework

作者：Chu-Hong Zhang, Bing-Xun Zhou, Xian Lin, Yi-Hong Mo, Jun Cao, Song‐Liang Cai, Jun Fan, Wei‐Guang Zhang, Sheng‐Run Zheng · 发表于：Inorganic Chemistry · 年份：2024 · DOI：10.1021/acs.inorgchem.3c04222 · 被引用次数：29 · 研究领域：Metal-Organic Frameworks: Synthesis and Applications、Covalent Organic Framework Applications、Molecular Sensors and Ion Detection

Posttreatment of pristine metal–organic frameworks (MOFs) with suitable vapor may be an effective way to regulate their structures and properties but has been less explored. Herein, we report an interesting example in which a crystalline nonporous Eu(III)-MOF was transferred to a porous amorphous MOF (aMOF) via iodine vapor adsorption–desorption posttreatment, and the resulting aMOF showed improved turn-on sensing properties with respect to Ag + ions. The crystalline Eu-MOF, namely, Eu-IPDA, was assembled from Eu(III) and 4,4′-{4-[4-(1 H -imidazol-1-yl)phenyl]pyridine-2,6-diyl}dibenzoic acid (H 2 IPDA) and exhibited a two-dimensional (2D) coordination network based on one-dimensional secondary building blocks. The close packing of the 2D networks gives rise to a three-dimensional supramolecular framework without any significant pores. Interestingly, the nonporous Eu-IPDA could absorb iodine molecules when Eu-IPDA crystals were placed in iodine vapor at 85 °C, and the adsorption capacity was 1.90 g/g, which is comparable to those of many MOFs with large BET surfaces. The adsorption of iodine is attributed to the strong interactions among the iodine molecule, the carboxy group, and the N-containing group and leads to the amorphization of the framework. After immersion of the iodine-loaded Eu-IPDA in EtOH, approximately 89.7% of the iodine was removed, resulting in a porous amorphous MOF, denoted as a-Eu-IPDA. In addition, the remaining iodine in the a-Eu-IPDA framework causes s...