Self-Similar\nLigand for 2D Zr(IV)-Based Metal–Organic\nFrameworks: Fluorescent Sensing and Catalysis

Two-dimensional (2D) metal–organic framework sheets,\nin\ncomparison to the 3D analogues, offer potential advantages for intercalation\nof guest components between the layers, exfoliation/dispersion into\nsolutions, and processing into thin films. As a versatile platform\nfor leveraging organic functions, the 2D Zr(IV)-carboxylate net here\nfeatures a dendritic Sierpinski tritopic linker with conjugated alkyne\nbranches and a photoactive triphenylamine core. The 2D solid can be\neasily dispersed in water and many other solvents, resulting in stable\nand fluorescent suspension for sensing nitro aromatic compounds and\nFe<sup>3+</sup> ions with high quenching efficiencies and ultralow\nlimits of detection. Also, the neighboring alkyne units of the coordination\nsolid undergo thermal cyclization (e.g., at 320 °C) to form cross-linked\nnanographene-like components to afford robust porosity, which substantially\ntakes up PdCl<sub>2</sub> (atomic ratio of Zr/Pd, 2.4:1) to afford\na heterogeneous catalyst for Suzuki–Miyaura coupling reactionsdirect\nin air and without the need for phosphine ligands.