Two new luminescent Cd(II)/Zn(II) metal–organic frameworks for exceptionally selective detection of picric acid explosives

Abstract

Two new coordination polymers, {[Cd(BIDPT)(oba)]·0.5H2O}n (1) and {[Zn(BIDPT)(4,4′-sdb)]·2.25H2O}n (2) (BIDPT=4,4′-bis(imidazol-l-yl)diphenyl thioether, H2oba=4,4′-oxydibenzoic acid, 4,4′-H2sdb=4,4′-sulfonyldibenzoic acid), have been solvothermally synthesized and characterized. Both 1 and 2 show 2-fold interpenetrating 3D frameworks with {65∙8} cds and {66} dia topology, respectively. These two coordination polymers show strong luminescence and their luminescence could be quenched by a series of nitro explosives. Importantly, they exhibit very highly sensitive and selective detection of picric acid compared to other nitro explosives.