Tetra(4-imidazoylphenyl)ethylene based metal-organic frameworks for highly selective detection of TNP and Fe3+

Two new 3D metal-organic frameworks (MOFs), namely {[Cd-4(L)(2)(oba)(4)]center dot 4H(2)O}(n) (1) and {[Co-4(L)(2)(BPDC)(4)center dot 4H(2)O]center dot 5MeCN center dot 5H(2)O}(n) (2), have been fabricated by reactions of tetra(4-imidazoylphenyl) ethylene (TIPE) (L) with cadmium nitrate and 4,4'-oxybisbenzoic acid (H(2)oba), cobalt nitrate and 4,4'-dicarboxylbenzophenone (H2BPDC), respectively, under hydrothermal condition. X-ray crystallographic analysis indicates 1 is a 4-fold interpenetrating 3D porous structure, displaying a (4, 4)-connected 4-c afw network with the point symbol of {{3.75}{3.7.7.7.7(2).7(2)}}. 2 shows a 3D -> 3D 4(2 + 2)-fold interpenetrating 2-nodal (4, 5)-connected 4,4-c 4T67 network with the Schalfli symbol of {{4.64.8}2{42.62.82}}. Significantly, fluorescence measurements reveal that 1 and 2 have good selectivity and sensitivity toward picric acid (TNP) through photoinduced electron transfer mechanism. Besides, 1 can also be employed as a highly selective sensor for Fe3+, making it a promising bifunctional sensor.