Molecular Scalpel to Chemically Cleave Metal-Organic Frameworks for Induced Phase Transition
Molecular Scalpel to Chemically Cleave Metal-Organic Frameworks for Induced Phase Transition
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分子手术刀化学裂解金属有机框架以诱导相变
DOI：
10.1021/jacs.1c02379
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发表时间：
2021
影响因子：
15
通讯作者：
Qiao Shi-Zhang
中科院分区：
文献类型：
--
作者：
Zhou Xianlong;Dong Juncai;Zhu Yihan;Liu Lingmei;Jiao Yan;Li Huan;Han Yu;Davey Kenneth;Xu Qiang;Zheng Yao;Qiao Shi-Zhang
由于金属中心和不同有机连接体的各种组合，金属有机框架（MOF）的自下而上化学合成允许显着的结构多样性。然而，制造通常符合经典的硬酸和软酸碱 (HSAB) 理论。这限制了用逆路易斯类型的金属离子和配体直接合成所需的 MOF。在这里，我们提出了一种自上而下的策略，通过使用新型“分子手术刀”对 MOF 进行结构裂解来触发相变，从而打破这一限制。由硬酸（Cu2+）金属和硬碱配体制备的传统CuBDC MOF（BDC = 1,4-苯二甲酸）被作为化学手术刀的抗坏血酸化学裂解，以制造由软酸（Cu1+）和硬碱（BDC）组成的新的Cu2BDC结构。通过一系列氧化还原步骤来调节铜离子的化学态和配位数，实现受控相变，从而导致化学成分和催化活性的显着变化。详细阐述了结构断裂和重排的机制见解。我们表明，这种新颖的策略可以扩展到通用的铜基 MOF 和超分子，用于从现有结构中纳米铸造出独特的结构。
A bottom-up chemical synthesis of metal–organic frameworks (MOFs) permits significant structural diversity because of various combinations of metal centers and different organic linkers. However, fabrication generally complies with the classic hard and soft acids and bases (HSAB) theory. This restricts direct synthesis of desired MOFs with converse Lewis type of metal ions and ligands. Here we present a top-down strategy to break this limitation via the structural cleavage of MOFs to trigger a phase transition using a novel “molecular scalpel”. A conventional CuBDC MOF (BDC = 1,4-benzenedicarboxylate) prepared from a hard acid (Cu2+) metal and a hard base ligand was chemically cleaved byl-ascorbic acid acting as chemical scalpel to fabricate a new Cu2BDC structure composed of a soft acid (Cu1+) and a hard base (BDC). Controlled phase transition was achieved by a series of redox steps to regulate the chemical state and coordination number of Cu ions, resulting in a significant change in chemical composition and catalytic activity. Mechanistic insights into structural cleavage and rearrangement are elaborated in detail. We show this novel strategy can be extended to general Cu-based MOFs and supramolecules for nanoscopic casting of unique architectures from existing ones.