Ye Qingyu, Herlinger Isabelle A, Fredin Lisa A, Cairnie Daniel R, Yang Xiaozhou, Yan Minliang, Morris Amanda J
Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24060, United States.
Department of Chemistry, Lehigh University, Bethlehem, Pennsylvania 18015, United States.
J Am Chem Soc. 2025 Sep 24;147(38):34690-34696. doi: 10.1021/jacs.5c09921. Epub 2025 Sep 9.
Recently photoinduced dynamic ligation in a metal-organic frameworks (MOFs) was reported, where a long-lived charge-transfer excited state (ca. 30 μs) featuring partial dissociation between the carboxylate linker and metal-based node was probed by time-resolved infrared (TRIR) spectroscopy. The study offers a new mechanistic perspective to evaluate the potential contribution from the excited state molecular configuration to the performance of MOF photocatalysts. In this work, by employing MIL-101(Fe) as the study platform, we have further explored the influence of intramolecular interactions on the stability of relevant excited states and demonstrated the effective tuning of their lifetimes through the incorporation of different functional groups into the system. The correlations between the varied excited state lifetimes and coordination configurations with specific functional groups (-NH or -NO) was inferred from the analyses of infrared spectroscopic data and theoretical calculations, revealing the essential role of the intramolecular interactions (i.e., between the added functional groups and the carboxylate group) in the modulation of system energetics. Overall, the work presents a pathway to tune the excited state dynamics and expands the knowledge regarding the photoinduced dynamic ligation in carboxylate-based MOFs.
最近有报道称在金属有机框架（MOF）中发生了光诱导动态连接，其中通过时间分辨红外（TRIR）光谱探测到一种长寿命电荷转移激发态（约30微秒），其特征是羧酸酯连接体与金属基节点之间存在部分解离。该研究为评估激发态分子构型对MOF光催化剂性能的潜在贡献提供了一个新的机理视角。在这项工作中，我们以MIL-101(Fe)作为研究平台，进一步探究了分子内相互作用对相关激发态稳定性的影响，并通过将不同官能团引入体系，证明了对其寿命的有效调控。通过对红外光谱数据和理论计算的分析，推断出不同激发态寿命与特定官能团（-NH或-NO）配位构型之间的相关性，揭示了分子内相互作用（即添加的官能团与羧酸酯基团之间的相互作用）在调节体系能量学方面的重要作用。总体而言，这项工作提供了一条调节激发态动力学的途径，并扩展了关于基于羧酸酯的MOF中光诱导动态连接的知识。
