Mixed-Ligand Strategy for the Construction of Photochromic Metal-Organic Frameworks Driven by Electron-Transfer Between Nonphotoactive Units

Metal-organic frameworks (MOFs), as an emerging hybrid material, have been well explored in numerous areas such as adsorption, separation, catalysis, magnetism, photoluminescence, etc. Recently, the intermarriage of MOFs and photochromism gives birth to a new category of hybrid materials with multiple photoresponsive functionality. Hitherto, most of photochromic MOFs are constructed from photoactive units like pyridinium-derivatives. We, herein, propose a mixed-ligand strategy for the fabrication of photochromic MOFs driven by electron transfer (ET) between nonphotoactive units, that is, the coordinative linkage of electron-rich carboxylate as electron donors (EDs) and conjugated pyridine ligands as electron acceptors (EAs) via the framework approach.