A stable 3-D Cd(II) metal–organic framework formed by aromatic carboxylate and flexible imidazole ligand for sensing of nitroaromatic explosives

A stable 3-D metal–organic framework (MOF), [Cd(H2DTPA)(1.2-mbix)]n (1), has been constructed with aromatic 2,3-dihydroxy terephthalic acid (H4DTPA) and cadmium salt under solvothermal conditions. The structure shows that H2DTPA2+ concatenates two Cd(II) cations to form a 1-D folded chain; the flexible nitrogen-containing 1,2-mbix sections link two adjacent 1-D chains into a 3-D framework. Complex 1 exhibited strong ligand-derived photoluminescence and was sensitive to nitroaromatic explosives (2-nitrophenol, nitrobenzene, 4-nitrophenol, 4-nitrotoluene and 4-nitrochlorobenzene).