Self-Assembled Cd-MOF Material Supported by a Triazine Skeleton: Stimuli Response to Traces of Nitroaromatics and Amines

Abstract

As an important chemical raw material, nitro aromatic compounds (NACs) and primary aromatic amines are widely used in the chemical industry. However, they are serious pollutants, which have already threatened human beings and the environment. Therefore, it is critical to develop a simple strategy to detect them. Luminescent metal−organic framework (LMOF) sensors have been promising platforms for sensing NACs and aromatic amines because of stable pore structure, outstanding optical properties, fast response, excellent sensitivity, and low detection limit. In this work, a novel LMOF [Cd 3 (TDPAT)The structure was analyzed in detail and the results showed that Cd-MOF presented a unique hexagonal-petal shape composed of binuclear building blocks [Cd 2 O 13 ] connected by a triazine hexacarboxylic skeleton, which also showed an interesting three-dimensional porous structure. Through fluorescence properties and sensing experiments, we found that it possessed strong fluorescence emission and exhibited an excellent sensitivity for the detection of NACs. It could correspond sensitively to 2,4,6-trinitrophenol (TNP), 2,4dinitrophenol (DNP), p-dinitrobenzene (p-DNB), o-dinitrobenzene (o-DNB), p-nitrophenol phenol (PNP), and o-nitrophenol (ONP). Notably, it exhibited extremely low detection limits for TNP, DNP, and PNP at 0.089, 0.092, and 0.016 μM, respectively. In addition, it could distinguish a class of isomers of primary aromatic amines (OPD, MPD, and PPD) through fluorescence properties experiment and detect OPD and MPD sensitively.

Highly pKa-Sensitive Colorimetric and Fluorescence “Turn-on” Chemosensors for Trinitrophenol and Crystallographic Investigation of Their Solid-State NIR-Emissive Host–Guest Adducts

“…Fluorescence-based chemosensing is a cheap, sensitive, and portable technique for detecting hazardous species from various analytical and environmental samples. ,, Although several fluorescence chemosensors based on metal–organic frameworks (MOFs), ,− coordination polymers, ,, supramolecules, and quantum dots have been reported for TNP, many of those chemosensors show fluorescence quenching with TNP. A fluorescence “turn-on” signal is preferred for chemosensing applications, as it can provide a clear visualization. − However, reports on fluorescence “turn-on” chemosensors for TNP are minimal. ,− ,,, Most importantly, a chemosensor for TNP should be capable of distinguishing it from closely analogous compounds like TNT, 2,4-dinitrophenol (DNP), p -nitrophenol ( p -NP), o -nitrophenol ( o -NP), phenol, dinitrobenzene (DNB), DNT, 4-nitro toluene (NT), and nitrobenzene (NB), but development of such selective chemosensors is a challenging task. − The mechanism by which a fluorescent chemosensor works becomes crucial when the analytes under study have closely analogous structures. The TNP chemosensors reported so far work based on different mechanisms such as resonance energy transfer (RET), intramolecular charge transfer, ground-state complex formation, and photoinduced electron transfer (PET). , Moreover, some reported TNP chemosensors suffer interference from other NACs, especially from 2,4-DNP and p -NP.…”

High-fidelity detection of picric acid following proton prompted fluorescence quenching by a novel acridine yellow G-based binuclear ZnII-metallacycle

“…The immediate geometry acquired by each Zn II -centre was observed as a distorted tetrahedron wherein bond lengths and angles were comparable to those found in closely related systems. 41,42 This distortion of the binuclear metallacyclic assembly is hosted by anti -periplanar conformation of acridine moieties which most likely stabilized the acquired geometry of the molecule. Moreover, two solvent molecules, i.e.…”

Preparation of a Tetra-Imidazolium Salt and Sensing for p-Dinitrobenzene

“…The detection of nitroaromatics in recent years has attracted extensive attention because these types of compounds are explosive, posing a threat to public safety. − Compared with traditional detection methods (such as LC–MS, GC–MS, and HPLC), − the fluorescence method has some advantages, such as high sensitivity, speediness, and easy operation. − Among these chemosensors, the forces acting between the host and guest are mostly hydrogen bonds (such as N–H···O, O–H···O, and C–H···O). Hence, it is a meaningful work to design and synthesize hosts with active hydrogen atoms.…”