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

Abstract

Two new 3D metal-organic frameworks (MOFs), namely {[Cd4(L)2(oba)4]·4H2O}n (1) and {[Co4(L)2(BPDC)4·4H2O]·5MeCN·5H2O}n (2), have been fabricated by reactions of tetra(4-imidazoylphenyl)ethylene (TIPE) (L) with cadmium nitrate and 4,4′-oxybisbenzoic acid (H2oba), 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 Schälfli 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 photo-induced electron transfer mechanism. Besides, 1 can also be employed as a highly selective sensor for Fe3+, making it a promising bifunctional sensor.