Luminescent Terbium-Organic Framework Exhibiting Selective Sensing of Nitroaromatic Compounds (NACs)

Abstract

An open terbium-organic framework (UPC-11) based on a rigid tetracarboxylate ligand was successfully assembled, which exhibits excellent solvent-dependent photoluminescence (PL). Moreover, UPC-11 displays rapid and selective sensing of nitroaromatic compounds (NACs), especially for 4-nitrophenol (4-NP), which represents the first Tb MOF that can be used as fluorescence detection of 4-NP. N itroaromatic compounds (NACs) have become serious pollution sources of groundwater, soils, and other security applications due to their explosivity and high toxicity. 1,2 Hence, the convenient and high-efficiency detective technologies based on the NACs have received much attention from chemists. Although some traditional detective methods bear high selectivity such as metal detectors, gas chromatography, surface-enhanced Raman spectroscopy, electron capture detection, and cyclic voltammetry, 3−6 they are usually expensive, inconvenient, and not very good for manipulation. Therefore, new technologies need to be developed so that we may cheaply and rapidly complete detection. The fluorescencebased sensing materials have recently been considered as one of the most excellent and promising techniques in the detection of NACs, 7−9 because this kind of technique possesses several advantages such as high selectivity, simplicity, portability, and the ability to be applied in both solution and solid phases. 10−13 In the past decade, some oligomeric, polymeric, or nanoscale fluorescent materials have been prepared and used in the detection of NACs. 14−16 However, it is still a great challenge for chemists to develop novel fluorescent materials for the detection of NACs because it is not facile to introduce chromophores into the above-mentioned materials as fluorescence sensor.Metal−organic frameworks are a new class of crystalline materials, which are built from metal cations or clusters and organic ligands. 17−19 The fluorescent behavior of an MOF is highly dependent on the organic ligands and metal ion/cluster; thus, it is facile to construct fluorescent MOFs by using either organic ligands with chromophores or metal ions such as Zn 2+ , Cd 2+ , or Ln 3+ , or utilizing the combination of these two parts. 20−23 Li et al. pioneered the application of fluorescent MOFs on the detection of NACs. In 2009, they first reported a Zn MOF exhibiting fast and reversible detection of high explosives based on mixed ligands. 24 Following that, a series of fluorescent MOFs containing Zn 2+ and Cd 2+ ions were documented for the rapid fluorescence detection of NACs. 25−29 For example, Su et al. reported a two-dimensional Cd MOF that can recognize NACs with different numbers of nitro groups. 30 Moon et al. directly observed the interaction sites between NACs and the framework by a luminescent Libased MOF. 31 Surprisingly, fluorescence detection of NACs based on Ln MOFs was seldom explored, although Ln MOFs show characteristic emission properties and have been considered a class of popular luminescent materials that possess potential applications in bio...

Metathesis in Metal–Organic Gels (MOGs): A Facile Strategy to Construct Robust Fluorescent Ln‐MOG Sensors for Antibiotics and Explosives

“…This result indicates the excellent selectivity of the MOG (Eu) xerogel towards 4‐NP, even in the presence of other aromatics and aliphatic nitro compounds. As illustrated in Table S4, the high K sv value of the MOG(Eu) xerogel towards 4‐NP is comparable with that of the reported famous crystalline MOF sensors …”

Fluorene‐based Lanthanide Coordination Polymer: Structure, Luminescence and Sensing of Picric Acid

“…Up to now, various CP‐based sensors have been developed for the detection of cations, anions, small organic molecules and even humidity . To construct luminescent CPs, several factors must be taken into account, such as suitable structure, well‐defined topologies, coordination environments of the metal centers and choice of organic ligands . Generally, ligands which possess π‐electron‐rich aromatic moieties can enhance fluorescence intensity of CPs .…”

Highly selective and sensitive detection of metal ions and nitroaromatic compounds by an anionic europium(iii) coordination polymer

“…Many analytical techniques such as inductively coupled plasma mass spectrometry, cyclic voltammetry, atomic absorption spectroscopy and trained canines, ion mobility spectroscopy, Raman spectroscopy, high-pressure liquid chromatography have been employed to detect trace amount of Fe 3+ ion and 4-NP, [24][25][26][27] respectively. However, most of these methods require sophisticated equipment and tedious preparation procedures and accurate manipulation.…”