A microporous luminescent europium metal-organic framework for nitro explosive sensing

A microporous metal-organic framework (MOF) Eu₃(MFDA) ₄(NO₃)(DMF)₃ (1, H₂MFDA = 9,9-dimethylfluorene-2,7-dicarboxylic acid) has been solvothermally synthesized and structurally characterized by single-crystal X-ray diffraction. 1 is a three-dimensional coordination polymer with pcu type rod-packing structure, through which 1D rhombic channels penetrate. The solvent-free form 1a could be obtained by direct heating of 1. Both 1 and 1a exhibit high intensity red light emissions with high quantum yields and long luminescence lifetimes when excited at 336 nm at ambient temperature. The potential of 1a for nitro explosive sensing is studied through luminescence quenching experiments, which show that 1a is a potential luminescent sensory material for nitro explosives.