Luminescent Metal–Organic Frameworks with Anthracene Chromophores: Small-Molecule Sensing and Highly Selective Sensing for Nitro Explosives

Abstract

Five new luminescent metal–organic frameworks (MOFs), [Cd(bdc)(dia) 0.5 (MeOH)](DMA) 0.5 ( 1 ), [Cd 2 O(1,4-ndc) 2 (dia) 2 (H 2 O)]·DMA ( 2 ), [Cd(1,4-ndc)(dia)]·MeOH ( 3 ), [Cd(bpdc)(dia) 0.5 ]·DMF ( 4 ), [Cd(bpdc) (dia)]·DEF ( 5 ) (dia = 9,10-bis(1 H -imidazol-1-yl)anthracene), were obtained from solvothermal conditions and characterized by PXRD, IR, TG, and PL spectra. Single-crystal X-ray diffraction analyses showed that all compounds 1 – 5 display three-dimensional architectures with diverse topologies. Compound 1 was a 6-con pcu network based on dinuclear Cd cluster. Compound 2 features an eight-connected network constructed from a binuclear Cd cluster. Compound 3 presents a 3-fold interpenetrated four-connected dia topology. Compounds 4 and 5 exhibit a 3-fold interpenetrated six-connected pcu framework and a 3-fold interpenetrated four-connected dia net, respectively. Because compounds 3 – 5 have one-dimensional (1D) channels, the luminescence properties of 3 – 5 in different solvents were investigated systematically. Furthermore, compounds 3 – 5 display highly sensitive, selective, and well-recyclable properties in the detection of nitrobenzene (NB) and 2,4,6-trintrophenol (TNP) as fluorescent sensors.