Abstract While the dimensionality of covalent organic frameworks (COFs) is a fundamental determinant of their physicochemical properties, their precise control remains a mystery and poses considerable challenges. Herein, we present a novel reversible coordination‐directed clip‐off chemistry strategy for reversible dimensional programming of COFs. Utilizing COFs containing coordinative Ag–N bonds as templates, structural transformation from a higher dimension to the lower one can be achieved by selectively cleaving these linkages. Noticeably, a 3D COF is converted into an unprecedented 1.5‐dimensional (1.5D) COF, which is constructed with three‐dimensional (3D) bonds but exhibits one‐dimensional (1D) linear chains. This dimensional tailoring is fully reversible; reintroduction of Ag(I) repairs the cleaved bonds, restoring the original dimensions. Significantly, the derived lower‐dimensional COFs exhibit markedly improved efficiency in extracting uranium from seawater and mining wastewater.
Li et al. (2026) studied this question.