A 3D pillared-layer metal-organic framework with fluorescence property for detection of nitroaromatic explosives

A metal-organic framework (MOF) {[(CH3)(2)NH2](2)[Cd-3(NTB)(2)(BDC)]}4DMF (NTB = 4,4,4-nitrilotrisbenzoic acid; BDC = benzenedicarboxylic acid; DMF = N,N-dimethylformamide) (1) was synthesized via the solvothermal method. In 1, [Cd-3(CO2)(6)] SBUs are linked by NTB3- to form a perfectly 2D planar Cd(NTB) sheet, which is further pillared by BDC, resulting in a 3D pillared layer network. It displays highly selective and recyclable properties in the detection of nitroaromatic explosives such as nitrobenzene (NB), 1,2-dinitrobenzene (1,2-DNB), 1,3-dinitrobenzene (1,3-DNB), 1,4-dinitrobenzene (1,4-DNB) and picric acid (PA, also called 2,4,6-trinitrophenol). Additionally, through the comparison of quenching efficiencies, we can differentiate nitroaromatic explosives with different numbers and locations of -NO2 groups. According to the experimental results, 1 has great potential to be a favorable sensor for selective detection of nitroaromatic explosives, especially PA.