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 by L-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.
Bibliographical noteKAUST Repository Item: Exported on 2021-04-26
Acknowledgements: This work was financially supported by the Australian Research Council through Discovery Project programs (FL170100154 and DP190103472). J.D. acknowledges financial support from Youth Innovation Promotion Association CAS. Y.Z. acknowledges financial support from the National Natural Science Foundation of China (Grant 21771161, 22075250).
ASJC Scopus subject areas
- Colloid and Surface Chemistry