南开大学卜显和团队报道了高效自校准酸度传感的活化不稳定介孔Zr(IV)-MOF的稳定性和实用性研究。相关研究成果于2025年1月15日发表在《德国应用化学》。

活化不稳定介孔金属有机框架（MOFs）的实际应用往往受到其结构不稳定性的限制。增强其稳定性可以解锁有价值的功能。

该文中，研究人员使用含吡啶的两性连接体（PPTB）稳定了新型介孔Zr（IV）-MOF NKM-809的不稳定后活化结构。研究人员采用了两种策略：混合接头合成和接头安装。在混合接头方法中，研究人员在合成过程中加入了一种类似于PPTB的辅助接头TPTB，以提高框架的稳定性。在连接子安装方法中，研究人员将双位羧酸盐连接子（BPDC）引入NKM-809的配位不饱和位点。这些策略产生了稳定的衍生物，称为NKM-808.X（X=χPPTB）和NKM-809-BPDC，它们在不同的发射波长下表现出pH响应的双波长荧光。

值得注意的是，这些排放物在质子化和解离过程中发生了相反的变化，使其成为高度灵敏、自校准的酸度传感器。在NKM-809-BPDC中，连接体发射的额外淬灭（419 nm）最大限度地减少了固有干扰，实现了集成的质量和寿命自我监测。理论计算确定了传感过程中（n，π*）和（π，π*）。

研究发现展示了稳定介孔MOFs在实际应用中的潜力，以及对优化此类材料策略的宝贵见解。

附：英文原文

Title: Retrieving the Stability and Practical Performance of Activation-Unstable Mesoporous Zr(IV)-MOF for Highly Efficient Self-Calibrating Acidity Sensing

Author: Feifan Lang, Lulu Zhang, Yang Li, Xiao-Juan Xi, Jiandong Pang, Wenjun Zheng, Hong-Cai Zhou, Xian-He Bu

Issue&Volume: 2025-01-15

Abstract: The practical applications of activation-unstable mesoporous metal-organic frameworks (MOFs) are often constrained by their structural instability. However, enhancing their stability could unlock valuable functionalities. Herein, we stabilized the otherwise unstable, post-activated structure of a novel mesoporous Zr(IV)-MOF, NKM-809, which uses a pyridine-containing amphiprotic linker (PPTB). We applied two strategies: mixed-linker synthesis and linker installation. In the mixed-linker approach, we incorporated an auxiliary linker, TPTB, which resembles PPTB, during synthesis to improve the framework's stability. In the linker installation approach, we introduced a ditopic carboxylate linker (BPDC) into the coordination-unsaturated sites of NKM-809. These strategies produced stabilized derivatives, named NKM-808.X (X = χPPTB) and NKM-809-BPDC, which exhibit pH-responsive dual-wavelength fluorescence at distinct emission wavelengths. Remarkably, these emissions shift oppositely upon protonation and dissociation, distinguishing them as highly sensitive, self-calibrating acidity sensors. In NKM-809-BPDC, an additional quenching of the linker-emission (419 nm) minimizes inherent interference, enabling integrated quality and lifespan self-monitoring. Theoretical calculations identified transitions between (n, π*) and (π, π*) emission states during the sensing process and highlighted the role of a stable mesoporous network in achieving stronger protonation response. These findings showcase the potential of stabilized mesoporous MOFs for practical applications, alongside valuable insights into strategies for optimizing such materials.

DOI: 10.1002/anie.202422517

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202422517