Tunable emission from a porous metal-organic framework by employing an excited-state intramolecular proton transfer responsive ligand.

A novel molecular design concept to control the emission of a metal-organic framework, {Mg(DHT)(DMF)(2)}(n), (DHT: 2,5-dihydroxyterephthalate), based on excited state proton transfer (ESIPT) of the organic linker, DHT, is demonstrated. The framework unveils permanent porosity and exhibits ligand-based multicolor emission that can be tuned and well controlled by the solvent molecules in solution as well as in the solid state.